OP-TV
Wall abutment flashing for trapezoidal sheet.
Category
Flashings
Unit
per linear metre
Category guide
Flashings are folded profiles made of flat sheet that close the edges and junctions of a roof: the finish of trapezoidal sheet at the eaves (eaves trim), the ridge cap, the wall abutment flashing and the verge flashing for trapezoidal sheet, the eaves comb that closes the corrugations of the profile, and the cap for the T-18 profile. Flashings by developed width are made to a drawing for any detail of the roof or the facade, in the RAL colour of the roof covering.
The sheet is steel S320GD, galvanising Z275 (275 g of zinc per m², both sides) to EN 10346, polyester coating 35 µm. It is folded on a CNC machine to a tolerance of 0.2 mm, so the profile repeats identically on every piece. The sheet standard guarantees the steel substrate and the zinc thickness, not the shape — the shape and the developed width are set by the customer.
The developed width is the sum of all the sides of the profile in the flat, including the folds — the flashing is placed in a class by it, so it is measured before ordering. The flashing is laid in the direction of flow with the pieces overlapping and fixed with screws with an EPDM sealing washer or with rivets, and long runs need a point for expansion because the sheet lengthens in the sun. It is cut with shears or a nibbler, not with an angle grinder, so that the zinc layer and the coating are not burnt.
Questions and answers
The developed width is the width of the flat strip of sheet from which the flashing is folded: the sum of all the sides of the profile and the folds. Flashings are placed in classes by it, and the sheet is galvanised steel S320GD Z275 to EN 10346 with a polyester coating of 35 µm.
On a CNC machine to a tolerance of 0.2 mm, so the angle and the lengths of the sides come out the same on every piece of the batch. That matters for flashings that overlap in a run — eaves trim, verge flashing, wall abutment flashing — because pieces that differ cannot be fitted together without a gap.
Of colour-coated steel S320GD with Z275 galvanising (275 g of zinc per m², both sides) to EN 10346 and a polyester coating of 35 µm — the same sheet as the trapezoidal roof covering, so the colour and the service life are the same. On request also of aluminium, copper or stainless steel.
With a sketch of the profile giving the lengths of the sides and the angles, or with a drawing in the Flashing Designer tool on the site, together with the RAL colour and the total length. The developed width is calculated from the sketch, and the profile is folded on a CNC machine to a tolerance of 0.2 mm.