Weather resistant sealing band forming e.g. under-tile roofing felt on pitched roof - comprises nylon with added copolymer improving tear resistance, with specific water vapour resistance properties, UV inhibition and fibre reinforcement.

Abstract
A weather sealing band used in building construction, especially on pitched roofs as an under-tile roofing felt, is novel in comprising a polyamide sheet. Its mean vapour diffusion resistance is expressed as an air layer equivalent diffusion thickness of 0.1- 0.5 m. Preferably the actual sheet thickness is 20-250 mu m, especially 50-150 mu m. The polyamide is PA6 or PA6.6. It is thermally stabilised and may be mixed with a copolymer. UV stabilisation is included, together with fibre reinforcement. USE -Used as a nylon weather sealing band for external use, especially as an under-tile roofing felt on pitched roofs. ADVANTAGE - The band has improved water (vapour) resistance under a variety of climatic conditions. It can be produced by an extrusion process. Incorporation of a copolymer inhibits tear propagation. The UV inhibitor can be simply carbon black. Glass or plastic fibres are usefully incorporated for reinforcement.