Assembly instructions

1. INTRODUCTION

The purpose of the following instructions is to facilitate the handling, storage and installation of the supplied trapezoidal sheets, cassette profiles, facade slats, sandwich panels (hereinafter referred to as "cladding elements") and related bendable supplementary roofing elements. At the same time, we want to contribute to ensuring the correct functionality of building systems (e.g. roofs, walls or ceilings) made up of these elements. These recommendations correspond to the current state of technical knowledge. They are based on the applicable standards and regulations and take into account the applicable ČSN EN and regulations valid in the EU countries. Their aim is to help to ensure a technologically correct assembly procedure or the correct use of thin-walled profiles. However, they do not relieve the installer of the obligation to assess whether special measures or modifications to the generally applicable rules are necessary in individual cases. In the event of any ambiguity or doubt, it is essential to consult immediately with the designer, structural engineer or the technical department of the manufacturer or dealer. The installation of thin-walled profiles should, as a matter of principle, be carried out by companies with the necessary expertise and personnel. They must be able to carry out the installation in accordance with the detailed design, generally accepted technical principles, relevant applicable standards and safety regulations.

2. BEFORE ASSEMBLY

2.1. Technical documentation

When the installation starts, a detailed project must be available on site.

This should include the following information: the laying plan, the anchoring plan and the static calculation, as well as - to the extent necessary - the supporting structure - the type and width of the supports - the type of thin-walled profiles used, their dimensions, thickness and surface treatment, details of their laying - type of fastening and joining, including details of the appropriate type of fasteners and the necessary pre-drilling diameters - method of transverse and longitudinal contact of the individual sheet plates, including the type of sealing, if any - the method of termination at the edges and at least the main details - any bending-rigid connections together with the number and location of bolts - the planned openings including any necessary static reinforcement - if necessary, the length expansion of the profile material (roof and façade expansion) - the drainage and earthing solution (lightning protection) - any limitation of the profile clearance during the installation of the sheets or the laying of other roof layers - the marking of the shear fields for the reinforcement of the load-bearing system.

2.2. Transportation

CB PROFIL trapezoidal sheets and edge profiles are transported mainly on trucks in sealed packages, which usually have a maximum weight of 3 tons. The construction site is obliged to provide the necessary access route for the truck to the unloading site, with a total length of up to 18 metres and a weight of 40 tonnes. If the route is not ready, the driver is not obliged to unload at the required location and will dump at the nearest possible location due to the risk of damage to the truck and goods.

2.3. Receipt on delivery

After the trapezoidal sheets have been transported to the construction site, it is necessary to check before unloading that the number of packages, sheets and other accessories corresponds to the data on the delivery note and that there has been no visible damage to the delivery during transport. In case of any discrepancies, it is necessary to indicate this on the delivery note and CMR document, draw up a complaint report and then stop the acceptance and immediately contact our company CB PROFIL,a.s.
Each package of sheet metal is marked with a label on which the following information is usually given: the manufacturer, the name of the customer and the customer, the order number of the manufacturer and the package number.

According to the data on this label, it is then necessary to check when unpacking the packages whether the number of pieces of sheet metal in the package and their lengths correspond to the text on the label or the delivery note. When transporting multiple orders on one truck, care must be taken to ensure that the correct and appropriate order is unloaded. If you unload something different, you risk penalties for the extra costs incurred. Should any discrepancies be found, please contact our company.

2.4. Unloading

Before the shipment is unloaded on site, it is necessary to have sufficient space not only for storage, but mainly for handling the packages of delivered profiles. When stacking multiple packages, it is essential that the wooden pallets lie exactly on top of each other and that the sheets cannot be damaged (e.g. by subsequent lifting of the sheet package, shifting, etc.). Sheet metal packages must be stacked using appropriate handling and mechanisation equipment. For smaller lengths, generally up to 6 m, a forklift truck can be used. When handling with a forklift truck, it is recommended that the rails of the truck be lined with a suitable soft material to prevent damage not only to the profiles but also to their surface finish.

For longer or heavier deliveries, it is necessary to use a crane for unloading. When using construction or mobile cranes, fabric straps must be used as tie-downs. Steel ropes or chains must never be used. For packages over 8 m it is advisable to use a hoist. The slings must be secured symmetrically and at the centre of gravity.

Shocks and vibrations must be avoided when unloading the sheets. It is necessary to protect the edges of the packages in a suitable way during unloading to prevent mechanical damage - e.g. use spreader boards. CB Profil a.s. recommends unloading bales of metal sheets individually as a matter of principle, even necessary for long and heavy bales. When unloading several bales at the same time, damage to the sheets in the lower package is very common, as the wooden pallets used to stack the profiles are not designed to withstand the possible dynamic load of the upper bale during stacking.


For sandwich panels, we recommend the use of spacers, e.g. planks, to prevent the influence of the binding means on the edges of the packages from breaking (bending) the panel locks.
In case the sheeting package is placed directly on the roof, it is necessary to place it in a place that is statically assessed for this purpose (most often at the point of contact between the purlins and the columns). If there is any doubt about the correct placement or handling, the technical direction of the construction should be consulted immediately. Once the sheet piles have been placed in a suitable location, it is necessary to prevent any further movement of the sheet piles, in particular slipping or tipping. Care should also be taken to avoid strong winds after the profile bundle has been unwrapped during all handling operations.

2.5. Storage

In the event that the trapezoidal sheets, edge profiles and sandwich panels are not fully used on the day of unloading, they must be protected against weathering, mechanical damage, UV radiation and against deformation due to poor storage.
Sheet metal packages must be properly supported and stored at a slight slant in the longitudinal direction to allow any water ingress or condensation to drain away. For short-term storage (up to approx. 1 week) in the open air, the sheet metal packages must be covered with a cover that protects the sheet metal from rain and atmospheric impurities contained in the rainwater, but this must not be airtight (e.g. plastic sheeting), so that the sheet metal does not steam up and damage the paintwork! Proper ventilation must always be ensured so that the sheets are open at the ends of the packages. When storing bundles of sheets for longer periods, they must be stored under a roof in a dry and ventilated area in the storage hall. This prevents water from entering the bales, condensation and possible mechanical damage.

The Supplier assumes full responsibility for damages caused by improper storage of sheet metal bales.

Failure to comply with the storage conditions as described above may cause damage to the surface finish of the trapezoidal sheets and bent profiles on both sides. In the case of galvanised or aluminised finishes, so-called white or grey corrosion can occur = grey or whitish zinc oxide layers. The formation of white corrosion to a lesser extent does not constitute a serious defect and can be easily cleaned, for example by brushing with a nylon brush or by washing with special cleaning agents. If grey corrosion develops (due to condensation during storage) the surface damage is irreversible. In case of insufficient moisture drainage and failure to ensure ventilation of condensed water in the painted profile package, the reverse protective paint may adhere to the face side or the view side and maps may form together with dirt from the air, which can be washed off with a slightly acidic substance (e.g. diluted vinegar), but also corrosion may occur under the paint, resulting in cracking and peeling of the painted sheet layer.


Furthermore, the protective self-adhesive film must be removed, as it only serves as protection during handling and transport! We recommend removing it within 1 week at the latest. If the film is not removed in time, it will permanently adhere to the surface, which will crack over time and form a flaky surface. The exact degenerative process of the film cannot be determined in advance, it always depends on the intensity of light, UV radiation, air temperature and weathering.

2.6. Cutting of thin-walled profiles during assembly

The cutting of especially painted (coated) profiles on site must be minimized by careful design and subsequent production of sheets in precise lengths.
For example, electric sheet metal shears are suitable for cutting. In no case does the manufacturer recommend cutting trapezoidal sheets, sandwich panels, edge profiles and straight sheets with a grinding wheel tool !!!
When cutting or drilling sheet metal, the resulting dirt and sawdust must be removed from the surface of the sheet metal, e.g. by plastering with a soft broom. This must always be done at least at the end of the working shift, immediately in case of increased humidity, because especially hot sawdust or dirt starts to corrode quickly on the profile surface, which does not look aesthetically pleasing and is often the cause of claims for alleged corrosion of the profiles. Later, these sharp and corroding debris can erode the coating layer and become a site of increased risk of sheet metal corrosion.

3. ASSEMBLY

3.1. General instructions

We recommend checking the support structure before starting the installation, especially in terms of installation accuracy, horizontality, perpendicularity and parallelism. This is especially true if the installer is taking over this part contractually from another entity. If the structure is not in accordance with the design, we recommend that this be noted in the construction log or the work acceptance report and that any resulting extra work be resolved with the installer.
The installation must be carried out in accordance with the installation plan. If the reality on site is in conflict with the installation plan (e.g. different dimensions, different support structure, openings, etc.), the installation plan must be adjusted on the basis of a structural assessment of the specific situation.


The assembler must be aware that trapezoidal sheets are a construction product, i.e. they are not manufactured with zero tolerance, and that he is familiar with the ČSN EN 508-1 standard, which CB Profil a.s. has adopted as an in-house standard and all profiled products follow this standard. The standard specifies general characteristics, definitions, product marking and classification, together with requirements for the materials from which products may be made.

This European Standard incorporates standards related to the manufacture of trapezoidal sheets and their materials CSN EN 10143,CSN EN 10169, CSN EN ISO 6270-1, CSN EN ISO 6988, CSN EN ISO 9227 and related standards CSN EN 1993-1-3, CSN EN 10204, CSN EN 14782. Failure to comply with the above standards, especially for large roofs or facades or floors or other large units of trapezoidal sheeting, could lead to displacement of the grid and possible violation of the structural assumptions, therefore it is always important to stretch or compress the trapezoidal sheeting to the prescribed dimension (composite width). For facade sheets, the recommended maximum length of trapezoidal sheeting is up to 5 m in 0.50 mm thickness and up to 6-8 m in 0.63 mm thickness, depending on the height of the wave; if the length is different from the maximum recommended length, the lengths must be consulted. An additional problem with incorrect installation can be caused by people moving over the unattached sheet to the support structure, where wave expansion can occur. Sheets should therefore be accurately measured during installation and slightly compressed or expanded as necessary to ensure that they are laid in accordance with the laying plan. Any narrow gaps around the perimeter of the roof caused by manufacturing and assembly inaccuracies should be covered by a suitably shaped sheet metal flashing.

If the upper surfaces of the support structure are not parallel to the trapezoidal sheet, the resulting wedges need to be filled with a suitable material or the support structure needs to be supplemented with a shaped sheet metal storage rim so that the trapezoidal sheets are placed on the support with the entire surface. Storing the sheets on the edge only is not permitted. The possible suspension of lights, process piping, etc. directly behind the trapezoidal sheeting is only possible provided that the resulting stresses on each individual wave of sheeting do not exceed those considered in the structural design. It must be taken into account that the waves do not practically interact with each other and therefore cannot 'help' each other in transferring the loads. For an approximate calculation of the maximum load locally suspended behind a single wave, the relationship can be used:
‘maX = qtech b1. I [kN], where qtech [kN/m2] is the area load from technology (etc.) considered in the design of the sheet, b1 [m] is the modular width of one wave of the sheet (e.g.: 0.28 m for CB 150/280/0.75) and I [m] is the distance between the individual hangings on one wave of the trapezoidal sheet, where the value of I must not be greater than half the span of the trapezoidal sheet.
The actual connection of the hanging to the trapezoidal sheet shall not cause local weakening of the sheet and shall be designed for the corresponding load.

3.2. Connections - types of fasteners

A joint is usually the point of contact between steel trapezoidal profiles and another profile or similar building component, including the relevant fastener. The axis distances, the type and type of not only the connections but also the connecting material as well as the connections in the shear fields must be correctly assessed statically when designing and these data prescribed in the project documentation and anchoring plan must be observed unconditionally during installation. Furthermore, it is necessary to assess whether the actual state of the construction corresponds to the construction project. Any changes must be consulted immediately with the designer or the author of the anchoring plan. The fasteners are applicable according to the specific situation. However, they have some limitations, mainly depending on the type of material and the intended use. The manufacturer recommends the use of prescribed tools and installation aids for working with fasteners. For all types of bolted connections, the bolt tension and shear characteristics specified by the manufacturer can only be taken into account if the tightening torque forces and installation principles specified by the manufacturer are strictly observed. These include, in particular, for self-drilling screws, the diameter of the pre-drilled hole in question (this information should have been included in the laying plan or anchoring plan) and, for self-drilling screws, the drilling speed and the thickness of the materials to be drilled. When using screws with sealing washers, we recommend using tightening devices with a so-called depth stop so that the washer cannot be "over-tightened". The correct type of thread (in wood, sheet metal or thick-walled steel) must be selected for each type of connection. Self-drilling and thread-locking screws are most commonly used.

3.2.1. Screws and their applications

Screws can be divided according to different aspects:

A)      Depending on the need to pre-drill

1. Threaded - must be pre-drilled according to manufacturer's recommendations.
2. Self-drilling - are screws with a pressed drill bit, which the screw drills itself. With self-drilling screws it is necessary to remember:

  1. The drilling capacity of the screw varies in different ranges specified by the manufacturer, e.g. 1.5 - 6.0 mm. When used in steel less than 1.5 mm thick, the screw will not hold in the structure. When used in steel thicker than 6 mm, the bolt will not screw in or will break
  2. The so-called clamping or usable length of the screw - specified by the manufacturer. The length of the self-drilling screw is given from the bottom of the screw head to the end of the drill bit. The drill bit and several lower (leading) threads cannot be used for fastening (e.g. for screws with a drilling capacity of 4.0 - 12.0, the difference between the total, stated and usable screw length is more than 20 mm!!!).
  3. The maximum speed specified by the manufacturer must be observed, especially for screws with higher drilling capacity. Failure to follow these instructions may result in the drill bit "melting" - the screw cannot be used.

B)       According to the material of the screw

  1. Steel with different quality surface anticorrosive treatment.
  2. All stainless steel (mostly A2 steel). ATTENTION! All stainless steel screws are not drilled into steel plates, they are only suitable for joining aluminium plates or wood.
  3. Bimetallic - self-drilling stainless steel screws with welded steel drill bit suitable for steel structures.

C)       According to the material of the supporting structure

  1. Into ordinary structural steel.
  2. For high strength steel - special screws must be used.
  3. In wood - anchor depth min. 35 mm.
  4. In concrete - there are no self-drilling screws, anchorage depth min. 25 mm.

3.2.2. Anchoring of facade trapezoidal sheets and sandwich panels

Facade trapezoidal profiles are considered to be mainly trapezoidal profiles placed in a positive position (wider wool with a view) on a steel or wooden structure (cold halls) or on supporting thin-walled cassettes (insulated halls) filled with insulation material, usually mineral felt. In consultation with the sandwich panel manufacturer, the façade trapezoidal sheets can also be attached to sandwich panels with a polyurethane (PUR; PIR) or mineral core. The trapezoidal profiles can also be stacked in a negative position (narrower wool face), but this is a rare phenomenon from an aesthetic point of view.

The facade trapezoidal profiles are always attached to the structure in a narrower wave, or in the riverbed of the trapezoidal profile. Unlike the trapezoidal sheets used for the roof, this connection to the supporting structure is permissible.

Facade sandwich panels always have a wide choice of external face sheet depending on the manufacturer's range. Facade panels are divided into two basic types. Façade panels with an acknowledged joint and façade panels with a so-called hidden joint. In sandwich panels with an admitted joint (the screw head is visible on the façade), the profiling is so fine and the panel is so rigid that it is practically irrelevant at which point the screws are anchored, whether at the top of the wave or at the water drainage points. The only thing that must be observed is the distance of the attachment point from the edge of the sandwich panel, usually a minimum distance of 50 mm from the edge of the lock measured from the edge forming the vertical joint. At the same time, the connection must be 50 mm from the end of the sandwich panel (measured from the cut point). Failure to do so could result in panel deformation affecting the aesthetic appearance and strength of the façade cladding. Facade sandwich panels with a concealed joint have a precise location in the concealed lock area, but even here a minimum distance of 50 mm from the start and end of the sandwich panel measured from the cut point must be maintained.

Facade screws are produced for all types of structures - wood, concrete, steel. Facade screws must be made of stainless steel (natural or painted), as it does not corrode and so there are no rust lines from water running down the facade trapezoidal sheet or sandwich panel. Facade screws for sandwich panels differ in the length of their shank. In addition, these screws have a two-thread system, which differ in the pitch of the threads so as to secure the sandwich panel to the structure, but also to clamp the upper face sheet and the internal interior sheet together with the structure. This is to provide additional continuity between the layers of the sandwich panel. The facade screws are also available in more aesthetically demanding designs, e.g. the screw heads can have several shapes, from the most famous hexagonal SW 8 head to small hemispherical heads with torx, Allen, square or special toothed system hidden under the completely smooth screw head. It is also possible to meet with moulded plastic heads in the RAL colour scale.

When insulating masonry houses, where ventilated facades are used and where the external visual element is trapezoidal or corrugated sheet metal, it is usually necessary to use dowels for fixing to the lower supporting structure. When installing, the manufacturer's instructions must be followed, in particular as regards the method of fixing the dowel, the appropriate length and type according to the masonry material (brick, concrete, etc.).

The number and type of fasteners is determined by the designer, structural engineer, or the technical department of CB Profil a.s. or by one of the renowned fastener manufacturers. The design must take into account the slope of the façade, the relevant wind zone according to EN 1991-4, the height and shape of the building. Based on empirical experience, we list below the standards we have encountered in practice. However, please note that these cannot replace the design or anchor plan. In addition, basic general rules must be taken into account, namely that the wood bolt must be drilled at least 35 mm into the wood lath and for steel the thread must extend 15 mm beyond the structure. If the bolt is fitted with a drill bit (TEX), its length must be added.

- for eaves and plinth 5 - 6 pcs/m2, in the field 2 - 4 pcs/m2.
- edging elements (corners, eaves, etc.) 1 piece per 300 mm.
- longitudinal joint 1 piece á 300 mm.

The correct execution of the connection is considered as not overtightening but sufficient tightening of the bolt with washer by suitable setting of the depth stop on the tightening tool (profile tightener suitable for construction). The washer under the bolt must not push the vulcanised EPDM rubber beyond its edge during tightening and at the same time the rubber must be sufficiently compressed to ensure that the joint is watertight (see Figure 1, 2, 3).

All screws used on the outer casing must be fitted with a sealing washer. The normal diameter of the sealing washer is 16 mm. When using basalt sandwich panels, a larger diameter of 19 or 22 mm is recommended.

Align the screws with the colour of the facade:

A) Caps - tend to be (for standard colours) the cheapest and most used solution. However, apart from the risk of the cap falling off, steel screws (even with a good surface finish) can rust their heads and cause rust to run down the façade even earlier than if the cap had not been used. For this reason, we do not recommend using steel screws with or without caps on the facade!!!
B) Painting screw heads is therefore a much better solution in the long run. The disadvantages are higher price, longer delivery time and possible abrasion of the paint part during tightening.
C) The plastic coating of the bolt heads is pressed firmly onto the bolt head, so that rust can not occur. The disadvantage is the enlargement of the bolt head and, in terms of economic viability, the need for larger volumes of several thousand pieces.

3.2.3. Anchoring of roof trapezoidal sheets and sandwich panels

The anchoring of the external roof trapezoidal sheets and roof sandwich panels laid with the narrower wave upwards (negative position, the lock must always be on top!), which serve for water drainage, is always carried out via the top strip and via a suitable type of calotte. The calotte is a special aluminium alloy washer that follows the geometry of the top of the narrow wave. The calotte is fitted with a vulcanised elastomer or bonded neoprene. Kalota can be painted in the same shade as the trapezoidal sheet in the RAL scale or can be supplied uncoated in natural aluminium only. Kalota provides two basic functions, it reinforces the top wave of the trapezoidal sheet and contributes to a better watertight joint.

The main advantage of anchoring over the top wave of the trapezoidal sheet is the fact that the connection material does not lie in the riverbed of the trapezoidal sheet and is thus not subject to permanent water stress, including torrential rains, which can cause a full-scale water runoff over its top wave. For these reasons, it is advisable to consult the designer or the technical department of CB Profil a.s. about the appropriate shape of the profile in terms of water drainage through its riverbed. Another reason for anchoring over the top wave is the thermal expansion of the steel from which the trapezoidal sheet is made. The longer anchorage allows the bolt to work similarly to a hinge. Millimetre displacements of the sheathing due to thermal expansion or contraction are virtually zero or have a more favourable movement (swing) in the material due to the longer length of the bolts in contact with the plate structure. The most delicate load-bearing structure is the timber structure. Wood is an inhomogeneous soft material, for which the anchoring of the trapezoidal sheet through the top wave is more than suitable!!!

If this recommendation is not followed, and the installer anchors the trapezoidal sheets, metal tile roofing or sandwich panels through the bottom wave to the wooden structure, the following phenomenon can be expected. The screws will loosen due to thermal expansion and contraction and the joint will no longer be watertight. Due to the positioning of the bolts in the river bed, there will be a gradual retraction and consequent rotting of the bolt around the timber structure. The joint will therefore become structurally unreliable. Another danger is the aforementioned softness of the wood. If the installer does not sensitively select the depth stop in the tightening device, the bolt with the washer will be pressed into the wood, the washer will deform under the bolt head, forming a funnel shape and the bolt will be completely without EPDM sealing material at the shank under the head.

Roof fasteners for trapezoidal sheets are produced for all types of structures, wood, concrete, steel. In roof constructions, it is possible to use galvanized steel screws with steel or aluminium backing, which is provided with vulcanized EPDM sealing material (rubber type) or stainless steel screws with stainless steel or aluminium backing and also with vulcanized EPDM, the length of which always depends on the type of trapezoidal sheet used (wave height). The fasteners for sandwich panels are structurally different from those for trapezoidal sheets. Firstly, they differ in the length of the bolt shank, but more importantly they differ in the twin thread system. The threads are differentiated by the pitch, so that the sandwich panel is attached to the structure, but at the same time the upper face sheet and the inner interior sheet are clamped together with the structure. This is to provide additional continuity between the layers of the sandwich panel.

The number and type of fasteners is determined by the designer, structural engineer, or technical department of CB Profil a.s. or one of the renowned fastener manufacturers. The design must take into account the roof pitch, the relevant wind area according to EN 1991-4, the height of the building and the roof shape. Based on empirical experience, we list below the standards we have encountered in practice. However, please note that these cannot replace the design or anchor plan. In addition, basic general rules must be taken into account, namely that the wood screw must be drilled at least 35 mm into the timber lath, and for steel the thread must extend 15 mm beyond the structure. If the bolt is fitted with a drill bit (TEX), its length must be added.

- 5 - 6 pcs/m2 for the eaves and ridge (the ridge can be anchored into the bottom wave, the joint is covered with a ridge profile).
- in the field 2 - 4 pcs/m2.
- edging elements (ridge, gables, etc.) 1 piece á 300 mm.
- longitudinal joint 1 pc á 300 mm.

Attachment of metal sheets or sandwich panels to the roof is possible:

A) In the top wave over the mud - the best but also the most expensive solution. When the plates are expanded thermally, the desired bending of the bolts occurs together with the expansion or contraction of the plates.
B) In the bottom wave only on the steel structure!!! It is necessary to use a larger diameter washer (19 or better 22 mm) and for sandwich panels to use a threaded bolt under the head at the same time. As water flows through the bottom wave, extreme care must be taken when fitting. We consider it to be a mistake to install the bottom wave on a wooden structure, as the drying out of the wood may cause the screws to loosen and the subsequent loss of tightness.

3.2.4 Anchoring of the bottom bearing plates

The anchoring of load-bearing trapezoidal sheets in the positive position, laid with the narrower strip towards the structure, is usually carried out with the help of a shooting nail, a bolt in the concrete, a bolt in the steel structure or a bolt in the wood, depending on the type of structure and its strength, with a minimum placement on the structure of 40 mm in the extreme supports.

- The studs are used for attaching steel trapezoidal profiles to the supporting steel structure, most often from a thickness of 6 mm (in specific cases from 3 mm, see the documentation of the manufacturer of the respective studs).  The nails are shot into the steel structure using a shot gun. The nail is fired using a cartridge. The hubs differ in the force of the required blow depending on the thickness of the steel structure or the thickness of the top flange. As a rule, the impact force is around 350 J. The manufacturer's instructions must be strictly followed when using the hub.

- The connection of the bearing plates to the steel structure using the self-drilling screw (TEX) is carried out with a depth stop tightening tool. The self-drilling screws are fitted with a disposable drill bit at the end of the shank. The length of the drill bit determines the drilling capacity of the screw and the length of the screw shank determines its clamping capacity. It is also possible to use thread-locking screws in steel structures in pre-drilled holes of smaller diameter. The size of the drill bit is determined by the fastener manufacturer.

 - The connection of the bearing plates to the wooden structure with a threaded bolt into the wood is made using a tightening tool with a depth stop. These screws are distinguished by a steeper pitch and a sharp screw tip.

- The connection of the bearing plates to the concrete structure with a threaded bolt into the concrete is made using a depth-stopping tightening tool in pre-drilled holes. It is very important that the drilled hole has the correct width prescribed by the fastener manufacturer and that the depth of the hole is at least 10 mm deeper than the length of the bolt. This is due to backfilling of the bottom of the hole below the bolt tip due to the formation of a thread in the concrete. Should the screw tip hit the accumulated concrete dust at the bottom of the hole during the thread formation, the tightening tool will damage the screw head or bend the screw head. Care must also be taken to position the steel reinforcements in the concrete structure so that they are not damaged.

All the above mentioned fasteners, if they do not have an integrated washer under the head, shall be provided with a suitable washer of minimum diameter 16 mm. This will significantly improve the dynamics of the joint.  It must be remembered that trapezoidal profiles are thin-walled sheet metal products and therefore are at risk of being pulled over the bolt head or torn apart by sudden gusts of wind.

The number and type of fasteners is determined by the designer, structural engineer, or technical department of CB Profil a.s. or one of the reputable fastener manufacturers. The design must take into account the roof pitch, the relevant wind area according to EN 1991-4, the height and shape of the building. Based on empirical experience, we list below the standards we have encountered in practice. However, please note that these cannot replace the design or anchor plan. In addition, basic general rules must be taken into account, namely that the wood bolt must be drilled at least 35 mm into the wood lath and for steel the thread must extend 15 mm beyond the structure. If the bolt is fitted with a drill bit (TEX), its length must be added.

- at a distance of 1000 mm from the attic, gutter or ridge 2 pcs in each lower wave of the trapezoid at the contact with the purlin.
- around openings (RWA flaps, skylights, etc.) 2 pcs in each wave at the contact with the purlin or auxiliary structure.
- In the normal field, 1 piece in each wave at the contact with the purlin is sufficient.
- around - 1 pc every 300 mm.
- longitudinal joint 1 pc á 300 mm.

If the fastener does not have an integrated washer under the head, it must be fitted with a suitable washer with a minimum diameter of 16 mm!!! Make sure that any pre-drilling is correct!!! Take special care when selecting studs and follow the manufacturer's recommendations!!!

3.3 Mounting on the structure

Precise measurements must be taken before installation begins. Inspection of the supporting structure must be carried out so that errors and inaccuracies arising during installation can be eliminated in a timely and professional manner. It is recommended to mark the points for continuous checking of the assembly so that the installer can monitor the perpendicularity and compositional width of the trapezoidal sheet throughout the assembly. In practice, this means to measure and carefully fit the first sheet, check its perpendicularity and maintain its composite width. When laying the other trapezoidal profiles, it is necessary to ensure that they are seated in the correct position. The trapezoidal profiles can be slightly deformed in shape during assembly by 'stretching' or 'squeezing' them or, conversely, by compressing them in the direction of their width, thus introducing an error into the assembly if this deformation is accidental. Conversely, the same (but controlled) procedure can be used to eliminate any shape inaccuracy of the sheets from the factory. When anchoring the profiles to the structure, it is therefore recommended to continuously check the overall width on both sides of the profiles to avoid any "running away". Slight deviations in the flatness of the straight parts of the trapezoidal sheets caused by rolling or stresses in the sheet, as well as slight waviness of the free ends, do not adversely affect the service life or load-bearing capacity of the trapezoidal profiles and therefore do not constitute a significant and serious defect in the delivery. Major permanent changes in shape, in particular edge fractures at the transition between the flange and the rack, may reduce the load-bearing capacity of the sections. It must therefore be professionally assessed whether such profiles are still qualitatively sufficient. The fasteners should always start from the centre of the sheet and work towards the edges, paying particular attention to perpendicularity and width. The second option is to fix the first and last screws at the edges and then "fasten" the intermediate screws. (This is often how, for example, plastic light boards are often installed between steel trapezoids.) Depending on the project and the static calculation, the trapezoidal sheets can be mounted in both positive and negative positions. For safety reasons, overhanging trapezoidal profiles must be secured against tipping immediately after laying. It is then advisable to fit a steel termination profile at the free end of the trapezoidal profile. When laying, it is necessary to organise the work in such a way that, whenever the shift is finished or work is interrupted, all the laid sheets are fixed and preferably longitudinally connected to each other. At the end of the shift, the already unwrapped bales must be secured against spontaneous sliding, e.g. during wind gusts, storms, etc. Openings in the roof, e.g. gullies, in particular, but openings for skylights or roof lenses which have not been indicated in the project documentation may only be installed with the permission of the designer. See also the paragraphs 'spans' and 'shear fields'.

3.4 Sealing and connection to the roof pitch

The prescribed sealing of roof or wall systems with suitable sealing tapes or compounds shall be carried out at longitudinal and transverse joints. When designing the three, it is advisable to refer to CSN 73 19 01 and CSN 73 05 44. For the outer sheathing, when the roof pitch is below 10 degrees (approx. 17%), it is recommended to insert an additional sealing tape in the longitudinal joint of the two sheets, while it is necessary for pitches below 5 degrees (approx. 9%). It is advisable to seal the transverse joints of two trapezoidal sheets with tape at gradients below 6 degrees (approx. 10.5%). As the gradient decreases, the distance between the joints of the longitudinal joint also decreases. The minimum slope of a trapezoidal sheet with sealing of longitudinal joints (without connecting the sheets transversely) is about 2.5 degrees (approx. 4.5%) for a minimum wave height of 50 mm. For sheets that are cross-linked, a minimum slope of 3.5 degrees (approx. 6%) is quoted. These figures must of course be taken as ideal, with almost zero deflection etc. Similar principles apply to most sandwich panels (except special panels designed for low gradients).

3.5. Drainage

Drainage of roof areas should be addressed by the project. During the actual implementation, the installer must comply with all the measures specified in the project. If the drainage is carried out after the roof has been laid with a slight or zero pitch, it is advisable to make a drainage hole by cutting a cut-out at the point of greatest deflection of the roof profiles. The trapezoidal sheets should then be reinforced with reinforcing profiles with a recommended minimum thickness of 1,25 mm at the cut-out. If the trapezoidal sheets are used as a load-bearing structure of the roof or ceiling and do not form the roof covering, no special requirements are imposed on the direction of laying the sheets. However, it is preferable to lay the sheets against the main wind direction to prevent rainwater from blowing between the profiles. However, if trapezoidal profiles or sandwich panels are laid as the outer skin of the roof, laying against the main wind direction is necessary. When laying trapezoidal profiles as external roof sheathing, it is always necessary to lay the trapezoidal profiles so that the two sheets laid side by side meet longitudinally in the upper wave, not in the lower wave on the structure (i.e. in the 'negative' position), so that water cannot flow in the joint.

3.6 Ventilation and ventilation

The ventilation or cladding ventilation solution proposed in the design must be followed without fail. In the case of non-insulated cladding, condensation on the inside can be addressed by means of a special anti-condensation surface treatment CB FLIS (vlies or spraying).

3.7 Spans

For all openings in wall or roof profiles (skylights, lenses, RWA dampers, flues, technology penetrations, ventilated windows, doors, etc.), the load transfer at the opening must be statically correctly resolved. Openings in the roof must be properly secured during installation (nets, barriers). An EPDM pipe sleeve can be used to ensure the watertightness of penetrations up to a diameter of 660 mm.

3.8. Shear fields

Shear fields are part of the structural system of the building structure and must therefore be designed exactly as specified in the design. Subsequent changes to shear field areas such as roof openings must be structurally assessed and designed prior to implementation. Care must be taken to ensure that the trapezoidal profile is fixed in each wave in this area and that the specified joint distances are maintained at the longitudinal edges and longitudinal joints exactly as specified in the detailed design. In many cases, these joint distances are noticeably smaller than in conventional construction. Areas in the roof which serve as shear fields must be particularly visibly and clearly marked in the design, indicating that they affect the structural integrity of the whole building. Changing them on the building (e.g. by installing a roof lens) without first calculating the structural effect of these design changes is not possible.

3.9 Contact between different metallic materials

Coated thin-walled profiles can be assembled arbitrarily with all other metals, provided that a coating (painting) is maintained at the interface between the two metals. However, galvanised and aluminised or aluminium sheets must be separated from these other metals by subsequent painting or by inserting other material at the point of contact if the subsequent negative effects resulting from contact with other metals are to be avoided. The table below gives a useful overview of the possible or not recommended contacts between two different metals.

3.10. Repairs to the surface finish during installation

Repairs to galvanisation (e.g. indentation by the corner of the sheet metal being transferred, after a sharp object has fallen on the sheet metal) can be carried out by subsequent dry coating with a varnish with a minimum zinc content of 90%. The thickness of the varnish layer should be 50-100% greater than the thickness of the original zinc layer being repaired. Repairs to the coating layer - varnish (scratch, badly drilled hole, e.g. as a result of a broken drill bit or impact with a steel reinforcement, etc.) are carried out with an air-drying coating. It is advisable to consult the supplier for the selection of a suitable repair varnish, as different types of repair varnish are suitable for each type of finish. In any case, only those areas where the paint layer is scratched down to the zinc should be repaired. The repair should then be carried out with the smallest possible brush or wooden skewer and only at the point of damage and in the thinnest possible layer to avoid a colour trace on the façade. It must also be remembered that even a suitably selected varnish never has a degree of shade and gloss completely identical to that of the original varnish layer. In the event of a very slight scratch on the coating layer in areas where there is no direct water drainage, it is advisable not to repair the area in question, as the cathodic reaction of the inorganic material with the organic duroplast means that there is no risk of corrosion of the zinc layer lying under the duroplast layer. If it is necessary to subsequently paint larger areas of duroplast-coated profiles, the following principles must be observed:

3.11. Cleaning

As a matter of principle, areas contaminated with substances that may cause an increased risk of corrosion should be cleaned immediately. Often this can be done simply by washing with a damp cloth. Water or mildly alkaline cleaning agents are suitable for cleaning coated profiles. However, when using cleaning agents, a subsequent rinse with clean water is necessary. When cleaning mechanically, damage to the coating by abrasion or abrasion should be avoided. Even slight abrasion of the coating, e.g. with a powdered cleaner, results in a loss of gloss. Products containing chlorine or salmiak, nitro-solvents or sand must not be used. When cleaning PVC-coated profiles (Plastisol), agents containing PVC solvents such as aromatics, Xylol, etc. must also not be used.

3.12. Protective films

Furthermore, the protective self-adhesive film, which only serves as protection during handling and transport, must be removed! It is recommended to remove it within 1 week at the latest. If the film is not removed in time, it will permanently adhere to the surface, which will crack over time and form a flaky surface. The exact degenerative process of the film cannot be determined in advance, it always depends on the intensity of light, UV radiation, air temperature and weathering.

3.13. Handover of the building after installation

It is recommended to hand over the building immediately after the completion of the installation, but especially before starting work of other professions such as sealing, insulation, building skylights, masonry, etc. The handover of parts of the assembled cladding is also an appropriate solution. If this procedure is followed, many subsequent unpleasant conflicts, misunderstandings and claims of defects in the finished work can be avoided. The handover of the work or part of the work should take place by a joint inspection of the building and a handover report should be drawn up immediately afterwards.

3.14. Handover of finished shear fields

The handover of the installed profiles used to reinforce the building or part of the building is carried out in the same way as for the handover of other parts of the building, but acceptance by the investor, the client or the designer's delegated body is absolutely necessary. A written report must be drawn up on the handover of these parts of the building, the original of which is kept with the other documents on the construction work, one certified copy of which remains with the erection company.

3.15. Safety instructions during installation

  1. it is unacceptable to cluster people on the roof and thus exceed the loads considered in the structural design, person max. 110 kg/m2
  2. the storage of material on the roof must not exceed 75 kg/m2 (unless the structural design of the supporting structure and roof sheathing indicates otherwise), it must be evenly distributed, the material must be stored on the truss or its immediate vicinity. It is strictly forbidden to step on the stored material on the roof. It is forbidden to store material on or near a cantilever that will carry a skylight or other equipment in the future. The load at the point of the load can only be FULL, not on a prism not on a pallet. In other words, if the goods came on one pallet of X kg, these goods must be rearranged on two or more pallets or other suitable sub-sets that will distribute the load flat so as not to overload the structure.
  3. it is essential to use soft rubber shoes only, without a sample, to avoid damaging the zinc coating.
    !!!THE SAMPLE HAS A STREAK!!! (be careful in the rain it is dangerous). This applies to all installers who will be moving around the roof. At the entrances to the scaffolding tower landing, or other roof entry, we recommend that plastic mats are fixed to clean shoes. ENTRY IN BOOTS OR WORK SHOP SHOES, CANVAS SHOES WITH HARD PATTERNED SOLES IS STRICTLY PROHIBITED.
  4. Any highly exposed areas, the main routes where material is transferred, must be covered with geotextile or other suitable protective film that will resist tearing. The fabric or sheeting must be fixed or weighted to prevent personal injury (slipping)
  5. IT IS STRICTLY FORBIDDEN TO DRAG, PULL, MOVE, ETC. THE SHEETS ON THE ROOF. EXCEPT WHEN THE SHEETING IS SEATED DIRECTLY IN THE JOINT. Sheets may only be carried with regard to the BZOP of the building.
  6. IT IS STRICTLY FORBIDDEN TO ENTER THE SITE WITH A FLEXO, ANY CUTTING OR GRINDING OF ANCILLARY STRUCTURES MUST BE CARRIED OUT AT A SUFFICIENT DISTANCE FROM THE BUILDING.
  7. IT IS STRICTLY FORBIDDEN TO DRILL INTO THE TRAPEZOIDAL SHEET AFTER CLOSING WITH INSULATION FROM THE BOTTOM (EXCEPT FOR THE TEX SCREW), ONLY ORIGINAL LEVER SCISSORS MAY BE USED TO CUT THROUGH THE STANDING BOTTOM NARROWER WOOL, E.G. THE LEVER SCISSORS FROM HILTI.
  8. IT IS STRICTLY FORBIDDEN TO LEAVE BROKEN DRILL BITS, SCREWS, CUTTER BLADES AND OTHER IRON CORRODING MATERIALS ON THE ROOF.
  9. PLEASE NOTE THE INCREASED DANGER AT SKYLIGHT OPENINGS AND AT THE EDGE OF THE BUILDING WHERE INCREASED AIR INTAKE CAUSES A RISK OF SWEEPING THE INSTALLER OFF THE ROOF.
  10. Others such as workplace safety, health and protective equipment are governed by the Construction Health and Safety Code.

4. INSTALLATION OF VARIOUS TYPES OF CLADDING STRUCTURES

4.1 Installation of roof and ceiling structures

The unloading of the profiles is described in the Unloading and storage chapter. If whole packages of sheet metal are transported to the roof or ceiling structure, it is advisable to secure them with ropes against major movements, especially due to wind. In most cases, the roof or ceiling can be assembled directly from the structure, as trapezoidal sheets and sandwich panels can usually be considered as a load-bearing surface immediately after fixing to the structure. They are usually walkable (beware, not always!!!). Larger lone loads over 100 kg (such as bitumen bales, tanks, containers, machinery, apparatus, etc.) may only be temporarily placed on the profiles on beams or other suitable means of ensuring that the load is distributed over a sufficiently large area. The load-bearing capacity of the plates and the supporting structure must be taken into account. To be installed, the individual profile sheets are usually transported into position by hand. For safety reasons, it is advisable to wear protective gloves. The profiles should not be pulled or moved around the structure as this could damage the protective coating. The same applies to the correct laying of the profiles, the securing of the sheet metal sheets during installation, sealing, drainage, ventilation, penetrations, shear fields and contact between the various metal materials, the repair of the profiles during installation, their cleaning or the handover of the finished work as mentioned in the general section on the installation of the profiles.

4.2 Installation of wall structures

The installation of single or double wall structures is carried out depending on the height of the building, the type of construction and the applicability of the floor in front of the wall to be installed. According to these data, the use of mobile or stationary scaffolding, the possibility of using suspended scaffolding or a suspended gangway shall be assessed.
During the installation, the trapezoidal sheets are transported to the place of attachment, precisely positioned, fixed against unwanted movement and then attached to the substructure in the same way as described in the chapter "Installation on the structure". Even more care must be taken when installing walls than with roofs or ceilings, as the profiles are usually coated and even the slightest damage to the surface of the profiles, e.g. light scratches or abrasions, may be the subject of a claim. The attachment of the façade profiles should be carried out using a template or, for example, at least a taut string, as the fasteners are visible on the façade and irregular or inaccurate positioning has a negative effect on the appearance of the façade. For the same reason, it is also necessary to remove any drilling or cutting marks from the profiles immediately after installation, as they soon become corroded. This can damage the coating layer and, last but not least, the rust residues that run off leave unwanted marks on the facade. Slight variations in the length of the individual panels must be taken into account during installation. This phenomenon cannot be completely eliminated in production. When assembling the façade, it is necessary to align the sheets at the bottom of the eaves at the visible joints and to cover any length differences under the attic flashing at the roof (or under the bottom edge of the window). For securing the sheet metal sheets during installation, sealing, drainage, ventilation, penetrations, shear fields and contact between different metal materials, repairs to the profiles during installation, cleaning them or handing over the finished work, the same applies as mentioned in the general section on the installation of profiles and in the previous chapter.

4.3 Installation of trapezoidal sheets as hidden formwork

When using trapezoidal sheets under concrete, CB Profil a.s. recommends a minimum thickness of 0.88 mm for any trapezoidal profile that is suitable for the given span of the trusses, even if a thinner sheet would be suitable for the given load or concrete layer thickness. The reason for this is the large and difficult to calculate unexpected local loads, e.g. metal pipes pushing concrete (swing), which practically bounce on the upper flanges of the trapezoidal sheet, also the operators handling the pipe in protective footwear (boots, other hard-soled work shoes) are able to damage the shape of the trapezoidal sheet (stepping on the wave or otherwise deforming the

4.4 Installation of the torque connection

The moment connection serves to ensure the correct static action of the trapezoidal sheet, which was considered by the structural engineer when designing the sheet dimensions. It is formed by the mutual overlapping and bolting together of the two sheets to be contacted, which are already suitably extended for this purpose from the factory. The overlap of the plates is symmetrical to the support and must have a total length of 1.0 m.

Moment connections designed and marked by the designer - structural engineer in the erection plan, as overlapping of plates and detail of the moment connection drawn by the designer in the anchorage plan, must be made (offset) with an accuracy of ±1-50 mm. Failure to comply with this requirement constitutes faulty assembly, which may result in the need for additional fasteners, or the addition of additional reinforcing plates, or even the replacement of defective elements - based on a static assessment of the specific situation. The moment connection must always be made in accordance with the design (laying plan and anchorage plan). In particular, the connecting elements must be identical to the design. Any confusion between them may result in insufficient reliability of the moment coupling. In this case, the structural design of the plates would not be valid. The moment connection must be made in such a way that there are no gaps between the materials to be joined. The installer must ensure that the plates are joined precisely. Above all, gaps between the plates to be joined must be avoided in order to prevent additional stresses on the bolted joint (e.g. from levering).

4.5 Installation of arch profiles

The curved trapezoidal sheets are transported to the construction sites mainly on trucks in wrapped bales weighing max. 2.5 t, taking into account the length of the sheets and the radius of the curve. During transport, each bale must be properly supported so that the transport does not cause permanent deformation of the sheets, in particular an increase in the so-called taper. It is not possible to transport more than 2 bales on top of each other. Site acceptance, handling and storage are the same as for straight sheets. For prolonged storage, the manufacturer recommends careful shimming of the arches to prevent damage to the finish and permanent deformation of the shape. Before starting to assemble the arches, the supporting structure should be checked for accuracy of manufacture and assembly, particularly with regard to perpendicularity and parallelism. However, the most important thing is to check the accuracy of the designed radiuses.

The manufacturer recommends that these measurements be taken before the trapezoidal sheets are actually bent at the factory. This is because the bending technology allows the specified radius to be changed even during the actual forming. It is therefore possible to eliminate any differentiations that may arise during the manufacture and assembly of the supporting structure by curving the trapezoidal sheets. The manufacturer draws attention to the double-sided tilt when bending the trapezoidal sheets into curves. During the actual bending, the length of the run-up (distance of the first forming roll) is 340 mm for all lengths and the radius is 340 mm. The smaller the radius and the shorter the sheet, the more the run-up effect is felt. At larger radii and lengths, the effect is negligible. The manufacturer recommends marking check points so that the installer can monitor perpendicularity, parallelism and compliance with the composite width throughout the installation. In practice, this means taking a bearing, carefully fitting the first segment, checking its perpendicularity and composite width. It is not advisable to permanently attach the trapezoidal sheets to the substructure immediately after the first segment has been fitted. The manufacturer recommends that the installation process be carried out in such a way as to eliminate as far as possible the possibility of stresses between the cladding and the supporting structure. This means that 2-3 segments of the roof sheathing are carefully fitted, the sheets are secured against displacement and shimmed, interconnected and the shimming removed. The roof sheathing is then "seated" on the supporting structure. It is only at this point that it is connected to the supporting structure in the same way as for the wall structures.

The procedure is similar in the case of the installation of the insulated sheathing with the difference that the outer part of the roof sheathing "sits" on the spacer profiles. The fasteners must be fitted from the centre of the sheet to the edges, paying particular attention to the perpendicularity and width of the composition. Caulking, drainage, ventilation, finish repairs and handover follow the same recommendations as for untwisted roof construction. These manufacturer's recommendations apply only to the installation of curved roofs on a supporting or load-bearing structure.

4.6 Installation of translucent profiles

They are supplied both single-skinned boards in the form of corrugated and trapezoidal profiles and double-skinned insulation elements matching the sandwich panels. The following principles apply to single boards. When installing double skin elements, please ask for detailed installation instructions, which you will receive from us immediately.

INSTALLATION MUST BE ADAPTED TO THE TYPE OF MATERIAL:
In general, the following principles should be observed: the bolt holes should be larger than the bolt diameter.  In addition, when mounting in the top wave, the profiles (top wave) must be backed with a solid washer, the longitudinal joints are preferably joined with special rivets with washers, the so-called bulbtite rivets.

PVC
Characteristic: Transparent, possibly cloudy to a smoky or opal shade, but more brittle at the edges, least heat resistant, most extensible in length.
Installation: Pre-drilling holes 5 mm larger than the diameter of the bolt. Do not tighten washers too tightly, screws with a washer diameter of at least 22 mm are suitable. The support structure on which the lightening profiles rest must be painted white or silver, ventilation must be ensured underneath the lightening profiles, if the lightening profiles are overheated there is a risk of cracks forming and thus structural damage to the material. When cutting parts, we recommend cutting with a fine-toothed saw. When handling the parts in a bale, pay particular attention to the fragility of the material, especially edges and corners are at risk.

!!!THE TRANSLUCENT PROFILES ARE NOT WALKABLE!!!

Roof pitch min. 10' i.e. approx. 18%. Cleaning of light profiles is possible with water or common detergents, the surface must not come into contact with chemical solvents.

POLYESTER

Characteristics. The fibreglass is approximately 80% translucent, not clear, not transparent. Its great advantage is its resistance to thermal radiation, it can withstand temperatures up to 120°C. Fibreglass is mechanically more resistant than PVC. Depending on the quantity, fibreglass profiles can also be offered in different colours.
Pre-drilling holes 2mm larger than the diameter of the screw. Do not tighten the washers too tightly, screws with a washer diameter of at least 22 mm are suitable. When cutting parts, we recommend cutting with a fine-toothed saw. When handling parts in a bale, pay particular attention to the fragility of the material, especially edges and corners are at risk. !!!!TRANSLUCENT PROFILES ARE NOT WALKABLE !!!

POLYCARBONATE
Characteristic: Transparent with high impact resistance, excellent optical and favourable fire characteristics. Other advantages include cold bending, very good light transmission and a wide temperature range of use from -40°C to +115°C.

Installation: Cutting with a fine-toothed saw, also possible with a hand saw. Pre-drilling of holes 50% larger than the diameter of the screw. When cutting parts, we recommend cutting with a fine-toothed saw. When handling parts in a bale, pay particular attention to the fragility of the material, especially edges and corners are at risk.

!!!!TRANSLUCENT PROFILES ARE NOT WALKABLE !!!

4.6.1 Storage of translucent profiles

Translucent panels must be stored in a dry, flat area. Condensation between the panels must be prevented, and the panels in the package must be protected from external weather and sunlight (which can cause a "lens effect" and damage the bottom panels), as well as from heat radiation.

5. MAINTENANCE OF BUILDING UNITS MADE OF THIN-WALLED PROFILES

Maintenance of building units made of thin-walled profiles, trapezoidal sheets, sandwich panels and their accessories - e.g. flashing profiles - must be carried out according to the following guidelines.
Periodic inspection is to be carried out in particular for the fasteners by which these products are attached to the steel or concrete structure, and periodic inspection of the fasteners in the longitudinal connections of the sheets or longitudinal connections of the sandwich panels, the supporting cassettes and their accessories, the flashing profiles. The above inspections must be carried out after the first year in which the building is handed over to the owner for use, and subsequent inspections may be carried out at intervals of three years. At the same frequency, the sheets themselves must be checked for deformations indicating possible overloading or damage. Their surface finish should also be checked to prevent corrosion damage to the sheets. Where the sheets are contacted on site above the support by means of torque bolted joints, these bolts should be inspected annually after winter.
In the event of hazardous meteorological events occurring during the use of the building, where it can be assumed that the wind or snow loads have exceeded the local limits set by EN 1991-4 and EN 1991-3, it is imperative that an inspection is carried out immediately on all the above elements.

In particular, the following should be considered as a serious defect requiring immediate solution: dropped bolt head, trapezoidal sheeting over the bolt head, bolt pulling out of the sheeting or supporting structure, disintegration of the rubber part of the washer under the bolt, tearing or breaking of the trapezoidal sheeting, deformation or corrugation of the sheeting. The same applies to sandwich panels, load-bearing cassettes or trim elements. In these cases, it is imperative to contact the manufacturer to assess the situation on site and then to suggest appropriate repairs.
Common defects caused by ageing of surface materials, e.g. surface corrosion or loss of aesthetic appearance due to UV radiation, do not affect the load-bearing function. However, if corrosion is detected, it is necessary to renew the surface protection in time to prevent significant corrosive loss of material. If the sheet metal products are no longer under warranty and the building user is not satisfied with the appearance and wishes to restore their appearance with a new coating, it is imperative that a professional painting company be contacted and advised of the type of coating that was applied to the sheet metal products during manufacture. This will then prevent any possible flaking of the new finish.
The surfaces of thin-walled structures need to be kept clean. In particular, staining with aggressive substances (including many building materials) should be avoided. If dirt, algae, etc. adhere to these products, they must be removed gently so as not to damage the surface protection.
Inspection and maintenance should always be carried out by a suitably instructed person and should follow the prescribed safety instructions for working at height.

Please contact us if you have any further questions.