When standard flashings do not fit: ordering a custom folded profile

It is worth noting the missing dimension and making a cross-section of the installation point. Measuring the old flashing alone is often insufficient. The previous element may have been chosen incorrectly or may have become deformed. The reference point should be the current substrate, covering and the expected path of water drainage.

Two profiles shaped similarly to the letter L can perform different tasks. One protects a wall corner, the other forms a wall flashing. They differ in position, method of fixing and edge termination. The correct cross-section must take these conditions into account, not just the line visible from the outside.

This also applies to starter profiles. The element starting the standing seam covering has a different task than a flashing at the plinth with sandwich panels. Unusual flashings are worth describing by their place of use. The common name alone may be understood differently by the installer and the manufacturer.

During renovation, it is convenient to hand over the old flashing as a pattern. However, it must be stated whether it is to be copied or improved. Old water marks, bends and additional holes may show imperfections of the previous solution. A new copy will also retain its incorrect geometry.

Before ordering, check whether the roof or façade layers have changed. Insulating the wall, replacing the gutter and a different covering all affect the detail. Ridge caps, verge flashings and gutter aprons must match the current arrangement. Dimensions from before the renovation should not be adopted automatically.

In an asymmetric profile, it is easy to confuse its mirror image. The drawing must therefore indicate the visible side, the bending direction and the position on the building. For coloured sheets, this matters for appearance and for using the correct side of the material. The colour specification alone does not remove this ambiguity.

The leg lengths and angles must be given, together with information on how the dimensions were measured. It is worth indicating which edges are to be folded. The manufacturer can then assess feasibility. Not every tight arrangement of bends can be achieved on any machine and with any sheet thickness.

A longer element can reduce the number of joints. However, it will be more difficult to transport and handle. Access routes and the possibility of safe support must be taken into account. A long, thin profile can become permanently deformed before it reaches the installation site.

The order should include a breakdown into sections, taking overlaps into account. The sum of the total lengths of flashings ordered is not equal to the length of the finished eaves. Non-standard flashings should be planned together with the joints. This allows the number of joints to be reduced without making installation awkward.

Galvanised, aluzinc and coated sheets are not a single material category. The quotation should state the core thickness and the type of protection. For coloured surfaces, the colour, texture and gloss also matter. This allows offers for genuinely similar products to be compared.

The cost of a flashing depends on, among other things, the developed width, length, number of bends and material. A price per linear metre without the cross-section does not give the full picture. A wide profile uses more sheet than a narrow one. Additional ends and corners must also be included in the schedule before production is ordered.

If a detail is repeated many times, it is worth first verifying its geometry on a single section. A sample allows the fit, the side of the coating and access to fixings to be assessed. This applies particularly to complex corners and chimney flashings. A change before the entire batch is produced is usually simpler.

Once the cross-section has been agreed, the current version of the drawing must be kept. An additional verbal change to one leg can later make delivery inspection more difficult. Acceptance includes dimensions, number of pieces and surface condition. A non-standard profile should fit the designed detail without accidental adjustment on site.