Trapped water under metal roofing can soon produce corrosion problems, which will adversely affect the working effectiveness of the roof, produce leaking problems, and reduce the aesthetic qualities.

All of these problems can be solved by Delta-Trela which prevents moisture build-up and stops corrosion. It also has the added benefit of absorbing rainfall noise.

The two-part construction is made up of a base sheet (Delta-Vent S) which is a three-ply spun-bonded polypropylene breather underlay, which is covered by an 8mm thick dimple-textured random-fibre mat which provides both an air gap and effective method of drainage.

The complex structure of the dimpled spacer mat allows the use of standard fixing clips, and gives freedom to the metal cladding to expand and contract with temperature changes.

Delta-Trela can be used in all types of metal-clad pitched roofs and walls. It allows residual water vapour in rafters and sheathing to escape, thanks to the high permeability of the base sheet.

With noise pollution becoming an increasingly important factor in materials specification, Delta-Trela again offers benefits. It reduces the transmission of noise of rain and hail pelting against the metal surface by up to 8dB – figures backed up by tests carried out by the Scientific and Technical Construction Centre in Brussels.

Installation time reductions are another bonus from this system. It can be installed in any direction required so structural details are not a problem.

Fire resistance figures given by the company show that Delta-Trela has a B2 rating/DIN 4102.

In addition to the standard Delta-Trela, the company also offers Delta-Trela Plus. This option has an integrated self-adhesive strip to further ease installation of the sheet to the roof’s sub-structure.

Standard roll size for both options is 30m x 1.5m, with each roll weighing-in at 17kg.

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