IKO ULTRA Torch-Free (T-F) Underlay is a polyester reinforced bitumen membrane used as an underlay within a built-up roofing system. The membrane is coated on both sides with a self-adhesive bitumen SBS elastomeric coating.
The upper surface is protected with a protective film that facilitates rapid bonding of the waterproofing layers. The self-adhesive coating underside is protected by a release film.
The underside has a self-adhesive bitumen coating that provides a 40% partial bond, allowing vapour dispersion between the membrane and substrate. It also has a 75mm selvedge that facilitates rapid installation of the lap joints.
The IKO ULTRA T-F Underlay is used as a partially bonded underlay within a built-up roofing specification system. It is to be used only for main flat roof areas and roof pitches up to 5° if reliant on adhesion alone.
For roof pitches over 5°, this underlay should also be mechanically fastened in accordance with BS8217 Table 5 or the IKO specification documents.
The unique self-adhesive profile of the IKO ULTRA T-F Underlay allows for a partial bond to be achieved to the substrate, therefore, reducing the risk of blistering from any trapped vapour.
