Introduction: Moisture can cause persistent and often expensive or difficult to solve problems in buildings. If the moisture penetrates the structure, mould or even rot can develop. A roof must be designed and built to prevent moisture penetration as much as possible. In the event that moisture makes its way into the structure, it must be able to escape without harmful consequences.
We recommend the use of a vapour barrier if there is reason to believe that there is insufficient ventilation in the space under the roof. The vapour barrier is designed to prevent condensation formation and stop moisture from penetrating the roof insulation. Start by attaching the vapour barrier to the bottom of the roof at the gutter, in lengthwise strips along the roof. Attach the vapour barrier to the battening every 200 mm.
Begin installation from the LEFT side of the roof, seen from the gutter to the ridge. This ensures that the built-in gutter is always properly mounted and there is no problem with the sheet alignment. It may seem illogical to slide one sheet under the other, but it allows you to keep an eye on the overlap between the “tiles” during installation. These should be kept close together so that the gap remains as small as possible. This minimises the amount of water that gets under the plate, which has to be removed by the built-in gutter.
The correct positioning of the first sheet is very important for the final result of the roof. A mistake made on the first sheet will compound in the rest of the roof and will result in a poor final product. As such, we recommend aligning the first sheet very carefully. The easiest method is to attach a board to the underside of the roof at a distance of 40 mm, and align the roof from there. This keeps the roof perfectly straight and avoids a saw tooth effect along the bottom edge. This is necessary because the roof is not always perfectly rectangular, and deviations are always possible, especially on older roofs.
Screws must be driven into the sheets at right angles. A normal drill and bit holder should be sufficient.
NOTE: when installing ALUMINIUM roofing sheets, ONLY use stainless steel/Bi-Metal screws! NEVER use galvanised screws!
Place the screws in the valley of the sheets, just below the horizontal line of the roof tile pressings. The same screws can be used on overlapping sections. You will need approximately 9 to 10 screws per square metre for proper installation. This minimises the chance of noise problems or sheets blowing loose due to insufficient screws. This amount also takes the trim installation into account.
Distribution of the screws in a cross pattern:
A recurring question our help desk receives: can I walk on the roofing sheets during installation?
Yes, you can walk on the roofing sheets without damaging it. You will need to place your feet as illustrated below. Only place your feet at the same level as the screws.