T-Diff Pro

The installation is done by fastening to the roof beams and in a direction across the roof slope. The first strip starts at the eaves and then overlaps upwards towards the ridge or another connection. Airtight joints are made in the overlaps with a self-adhesive tape edge. When there is underlying roof insulation, the air gap is completely omitted against the underside of the underlay. For details and complete installation instructions, see the separate installation guide.

• The underlay roof is installed hanging over the rafters, not on solid wooden substrates.
• Unless otherwise stated, the latest recommendations in AMA-Hus (JSC.6) apply
• The roof's surface layer determines the minimum slope for the underlay roof, but always at least 14° (1:4)
• T-Diff Pro is a so-called diffusion-open roofing underlay where optimal function requires airtight installation from roof to ridge. An air gap between the underlying insulation and the roofing underlay is not required!
• Gently load the surface and immediately seal and repair any damage. Minor damages are repaired with repair and sealing tape recommended by TECCA. In case of major damage, replace the entire fabric between the rafters with a new piece.
• T-Diff Pro meets the requirement for penetration safety when all fastening such as nailing and battening (nail and load battens) of the fabric is complete! The maximum C-distance from the roof beams is 1200 mm.
• No depressions or backfalls should form in the underlay roof during fastening and fixing. Rolls should be stored upright on a flat and dry surface, protected from sunlight (UV) and precipitation.
• When installing in colder weather (< +5°C), the adhesive tape may need to be gently heated for optimal adhesion, as well as pre-warming the rolls beforehand.
• The surface should be dry, clean, and free from grease for the best adhesion of the adhesive tape and during all installation occasions.
• After installation, the underlayment must be completely enclosed and protected from sunlight (UV-). The maximum exposure time (UV-) before top covering is four months.
• Always cover with the surface layer as soon as possible to avoid impact from bad weather.
• TECCA T-Butyl splice tape is an approved splicing aid and sealant.
• To achieve optimal sealing at each mounted batten, the TECCA Batten Sealing Tape should be placed between the battens and the underlay before fixing and nailing. Screwed battens also improve the seal against the underlay.
• The use of TECCA Distance for underlay roofing is recommended centered under at least every other support batten (approximately 2 pcs/m roof) for better fixation of the sheet and its overlap between the rafters.