FR2517726A2

FR2517726A2 - Semipermeable roof linings of nonwoven fabric with bitumastic coating - rendered microporous by crazing developed on cooling hot coating

Info

Publication number: FR2517726A2
Application number: FR8122750A
Authority: FR
Inventors: Jean-Yves Meynard
Original assignee: Siplast SA
Current assignee: Siplast SA
Priority date: 1979-10-18
Filing date: 1981-12-04
Publication date: 1983-06-10
Also published as: FR2517726B2

Abstract

Semipermeable membranes for lining roofs covered with tiles or shingles are made by coating a nonwoven fabric with a layer of hot bitumen thin enough that, upon cooling, microcracks or crazing develops so that the coated layer is permeable to air but not to water. Membranes allow ventilation to reach the underside of the roof, without letting any water penetrating or condensing beneath the roof to fall into the space below the coated fabric. Pref. the nonwoven fabric is made of polyeser, polyolefin or vinyl fibres and weighs 75-100 g/m2 and the bitumastic coating weighs 150-300 g/m2. Bitumastic coatings may be applied to both faces of the fabric, pref. are sufficiently flexible for the coated sheet to be stocked in rolls.

Description

te Brevet principal décrit un matériau étanche à l'eau et perméable à l'air pour sous-toiture en éléments tels que tuiles, ardroises, shingles, constitué par une feuille de filaments agglomérés, tels que des filaments de propylène thermosoudés, enduite sur au moins une face d'une couche de bitume présentant une structure micro-trouée s'opposant au passage de liquide mais permettant l'aération. On obtient ainsi une barrière efficace contre les intempéries, à la fois souple et légère, résistante à la déchirure, permettant une bonne ventilation de la toiture tout en évitant la condensation en sous-face et dans l'isolant et en gardant l'isolation thermique. main patent describes a waterproof and breathable material for sub-roofing in elements such as tiles, slate, shingles, consisting of a sheet of agglomerated filaments, such as heat-sealed propylene filaments, coated on at least one face of a layer of bitumen having a micro-perforated structure opposing the passage of liquid but allowing aeration. This provides an effective barrier against the weather, both flexible and light, resistant to tearing, allowing good ventilation of the roof while avoiding condensation on the underside and in the insulation and retaining thermal insulation. .

On a en effet observé qu'en enduisant à chaud par les moyens usuels une nappe fibreuse non tissée d'une couche fine de bitume à chaud, celle-ci en se refroidissant présente une surface percée de multitude de petits trous ou craquelures, qui s'opposent à la pénétration d'un liquide, mais permettent le passage dé l'air. It has in fact been observed that by hot coating by conventional means a nonwoven fibrous web with a thin layer of hot bitumen, the latter on cooling has a surface pierced with a multitude of small holes or cracks, which s oppose the penetration of a liquid, but allow the passage of air.

On utilise par exemple du bitume fillerisé à raison de 200 à 300 gr. au m2 sur un support perméable en fibres d'un 2 poids de 75 à 150 gr. au m2. For example, fillerized bitumen is used at a rate of 200 to 300 gr. per m2 on a permeable fiber support with a 2 weight of 75 to 150 gr. per m2.

Or on a constaté que l'on obtient un produit ayant les mêmes propriétés, c'est-a-dire imperméable au liquide mais perméable aux vapeurs et à l'air, mais un peu plus lourd et résistant tout en restant souple, en enduisant la nappe fibreuse sur ses deux faces. However, it has been found that a product having the same properties is obtained, that is to say impermeable to liquid but permeable to vapors and air, but a little heavier and resistant while remaining flexible, by coating the fibrous web on its two faces.

A titre d'exemple indicatif et non limitatif, on répand à chaud par les moyens usuels d'enduction, sur les deux faces externe et interne d'une nappe de fibres de polyester, polypropylène, polyéthylène ou similaire, d'un poids d'environ 100 gr. au m2, des couchés de bitume fillerisé 90/30 d'un poids d'environ 200 gr. au m2. On constate qu'au refroidissement, ie bitume devient poreux tout en s'opposant au passage de liquide par capillarité. Malgré cette double enduction, le produit reste souple et léger et peut se présenter en rouleaux. As an indicative and nonlimiting example, hot spreading by the usual means of coating, on the two external and internal faces of a sheet of polyester, polypropylene, polyethylene or similar fibers, weighing about 100 gr. per m2, layers of 90/30 fillerized bitumen weighing approximately 200 gr. per m2. It is found that upon cooling, the bitumen becomes porous while opposing the passage of liquid by capillarity. Despite this double coating, the product remains flexible and light and can be presented in rolls.

Claims

- CLAIMS

1. Water-tight and air-permeable or vapor-permeable material according to claim 1 of the main patent for roofing in elements such as tiles or slates, characterized in that the flexible and light sheet of nonwoven fibers is coated with hot by conventional means on its two external and internal faces of a film of bituminized bitumen of a thickness such that on cooling these films have a micro-perforated or micro-cracked structure opposing the passage of liquid even by capillarity and allowing the passage of air or vapor.

2. Material according to claim li characterized in that the sheet of polyester, polyethylene, polypropylene, polyvinyl or similar fibers has a weight of about 75 - 100 gr. per m2 and each bitumen film with a weight varying from 150 - 300 gr. per m2.

3. Material according to claim 1, characterized in that the bitumen films, of the same thickness or not, remain flexible enough to allow the presentation of the material in rolls.