Adhesive membrane
A self-adhesive permeable membrane sheet ( 1 ), for use in a building structure, includes a continuous layer of a permeable pressure sensitive adhesive ( 8 ) attached to one surface of a permeable membrane sheet ( 2,4,6 ). Methods for using the permeable membrane sheet ( 1 ) in construction are also provided.
1. A self-adhesive construction membrane sheet comprising a continuous layer of an air and water vapour permeable pressure sensitive adhesive attached to one surface of a permeable membrane sheet, wherein the permeable membrane sheet is:
a water vapour permeable air barrier laminated construction membrane comprising three layers: a spunbond polypropylene layer, a microporous polypropylene film layer and a spunbond polypropylene layer, wherein the adhesive mixture used to form the continuous layer of an air and water vapour permeable pressure sensitive adhesive comprises, before drying or curing:
an acrylic pressure sensitive adhesive as base compound;
an air permeable agent;
a cross-linking agent; and
polypropylene glycol;
so as to provide, after drying or curing, the continuous layer of air and water vapour permeable pressure sensitive adhesive having tortuous air permeable paths therethrough.
2. The self-adhesive construction membrane sheet according to claim 1 wherein the continuous layer of an air and water vapour permeable pressure sensitive adhesive is from 30 to 100 microns thickness.
3. The self-adhesive construction membrane sheet according to claim 1 wherein the water vapour permeability of the continuous layer of an air and water vapour permeable adhesive is 50 perms or more.
4. The self-adhesive construction membrane sheet according to claim 1 wherein the self-adhesive construction membrane sheet maintains more than 70 percent of the water vapour permeability of the permeable membrane sheet.