No !. Full fill cavity insulation has to be all or nothing to prevent water using the edge of the insulation to cross the cavity. Maybe our resident BCO could comment on this.
- Vote on answer
- posted
20 years ago
Cavity Wall Insulation -> Advice?
Loading thread data ...
- Vote on answer
- posted
20 years ago
What water?
- Vote on answer
- posted
20 years ago
Wind driven rain getting into the cavity, which is there to stop the water getting into the house.
- Vote on answer
- posted
20 years ago
Is it really? what stops it getting into the cavity anyway?
- Vote on answer
- posted
20 years ago
Most bricks (engineering aside) and mortar are porous to varying degrees, and not every house was built by Gold Star brickies, which means the inevitable leaks. Cavity wall ties have a U-bend in the middle for the express reason that any water that gets in and flows along the tie, will drip off and drop down the centre of the cavity out of harms way. If we get a couple of days of driving misty rain, water drips in through the top of my south-facing patio door. The BBA? Agreement for rockwool cavity insulation gives more information, and there are plenty of references in Google, e.g. :-
Installation Details BBA Certificate No. 99/3637 relates to the latest design of cosythermRockwool blowing machinery equipment used with the 18mm or 25mm hole systems. The density achieved is in the target range 40kg/m³. The blown wool is installed through 18mm or 25mm diameter holes drilled at 1.5m centres in a staggered 'W' pattern. In facing brick or block walls these are normally located at mortar joint positions . Additional holes may be required, e.g.. at windows sills, around airbricks at the top of walls or under cables, to ensure the complete filling of the cavity. Making good usually takes place as filling proceeds.
Standards cosythermRockwool cavity wall insulation has been examined by the British Board of Agrément and certified for use in all exposure zones. The assessments are covered by Agrément Certificate 99/3637.
Building Regulations C4: A properly constructed masonry cavity wall insulated with cosythermRockwool blown wool will fully meet the requirements of Regulation C4, 'Resistance to weather and ground moisture'.