cavity wall does it breathe
Cavity wall insulation currently very cheap or free but be warned it can do more harm than good.
Just because the government is urging everyone to embark on a mass insulation program with generous attractive grants available, don’t be tempted into having this type of work done until you do your homework.
Cavities allow building to breathe, both moisture from inside the home and any damp that enters the wall from the outside has to dry out, bridge this cavity with material that can stay wet and you have the perfect recipe for disaster. Your may not notice the cavity is working until you stem the flow of air with moisture retaining material.
Over the years we have put right a few cavity wall jobs that caused horrific damp problems
We recently repaired a double brick cavity wall that had the mineral stuff blown in, it had been forced in with so much pressure it was just about solid.
The gable was in an exposed location, wind driven rain etc. They had experienced no problems until they had this work done, soon after they noticed internal damp patches all over the upper sections bedrooms, landing, hallway the lot.
Remedial work: When we opened up the wall we had to remove a mass of sodden insulation material, we replaced 50 bricks, re pointed the gable in natural hydraulic lime, and it’s now a breathable dry wall.
So If you want to get the cavity of your home filled then go for foam or bonded polystyrene beads, most firms use mineral wool as its cheap, go for foam or polystyrene or if the walls are old just don’t bother having this done, insulated from the inside with dry lining or go for exterior wall insulation, both these methods allow the walls to breathe and leave the integrity of the cavity intact
Chris Beaumont
Director
Wall2wall Solutions.co.uk
For more information Read this excellent article by the knowledgeable
Ask Jeff
http://www.askjeff.co.uk/cavity.html