Sheet for the snap seam part 2
Mounting strip
Seam sheets are most often ordered in long dimensions. Steel or aluminum sheet is subject to dimensional change due to temperature difference. In this case, we are talking about the length of the sheets, the size of which changes between the seasons of the year by 1,2mm/m for steel and 2,2mm/m for aluminium. With a rafter length of 7 m, a steel sheet is 8,4 mm longer in summer than in winter. Such a significant change in length must have its basis in the method of fixing the product to enable the sheet to work freely, because permanently fixed to the sheet base, without the possibility of length compensation, it will be deformed, i.e. the surface between the seams will be unevenly wavy. On the other hand, sheet width compensation, which is negligible, takes place between the seams.
Bratex Snap Lock seam sheets are attached to the substrate with galvanized screws without gaskets, through the mounting strip, which is covered after applying (snapping) the next sheet. Thus, unlike in the case of trapezoidal sheets and roof tiles, the product is mounted without visible screws. The mounting strip has pre-drilled holes. Each mounting hole has a length of up to 25mm, which allows the material to work freely between the seasons.
Seam mounting strip with mounting holes
As a result, even twelve-meter-long sheets can be laid on the roof without worrying about thermal expansion between the seasons, when the temperature of the material in the ground reaches -30oC and in the summer the sheet heats up to 70oC. The temperature difference between seasons is 100oC.
Double ended
The Bratex Snap Lock standing seam has a double-sided start of the sheets. It's 30mm of material that wraps underneath on the fastening belt at the eaves and stores at the ridge.
Two-sided hem finish
Please note that for the ridges (top and corner), dedicated F23 system ventilation slats are used, which are screwed to the sheet itself (not to the substrate), to which the ridge flashing is then screwed.
F23 ventilation strip for the snap seam
In this way, the sheet is not permanently attached to the substrate, it is possible to work when the dimensions change due to temperature differences. In addition, the ventilation strip ensures proper air flow between the eaves and the ridge. The strip is perfectly matched to the Bratex Snap Lock seam.
Rounded corners
The Bratex Snap Lock standing seam has rounded corners of the mounting strip and the beginning. It's a more comfortable job for contractors, less body scratching and material damage.
Rounded corners of the mounting strip
Lid of the seam
The product is delivered from the factory with a seam-shaped lid on both sides. Depending on the decision on the direction of coverage (from left to right or vice versa) or depending on the application (e.g. on the attic), the roofer has the option of closing one or two lids.
Closure of the snap seam lid
The lid is closed with roofing pliers.
Soundproofing and anti-condensation fleece
As an option, we offer factory-applied SOUNDCONTROL soundproofing fleece with a thickness of approx. 4mm. It is used only for thermally insulated roof partitions. The purpose of this interlining is to dampen the sound of rain and other sounds from the environment by up to 6dB, and to reduce the possible operation of the display surface on windy days.
SOUNDCONTROL soundproofing fleece
It is worth noting that the soundproofing interlining raises the level of the display surface. For the version of the product with soundproof fleece, we recommend using full boarding, because on openwork boarding, places with boards will become visible on the surface of the sheet.
The second product option is the DRIPSTOP anti-condensation fleece, which is used only for non-insulated roof partitions, e.g. when the sheet is installed in warehouses and garages. Anti-condensation fleece absorbs moisture resulting from condensation and prevents condensation from falling on the building equipment. Care should be taken to ensure efficient gravitational ventilation in the direction of the eaves-ridge, then the surface of the interlining is subject to continuous drying.
It is worth noting that the Bratex Snap Lock seam with an applied interlining (SOUNDCONTROL or DRIPSTOP) is also available with a profiled display surface. In addition, as befits a high-quality product, the interlining is finished 15 cm from the edge of the sheet. Thanks to this, the transverse connection and overlaps on the eaves do not require tanning or peeling off. This way of applying the fleece is possible thanks to the use of an applicator behind the profiling line and the guillotine, i.e. the fleece is glued to the sheet that leaves the profiling line.