Free grants - blown mineral wool cavity wall insulation

[matz]

Just had a guy round flogging cavity wall insulation. We appear to be entitled to have it done free of charge via a grant etc and I think they would use blown mineral wool. Our house is detatched about 30yrs old, brickwork not rendered.

After reading up on this method of insulating wall cavities, it seems it may not be such a good idea due to the wool possibly getting damp, condensation forming etc through cold spots in unfilled areas etc etc

I'm not bothered about having it done really but its free of charge and I guess will improve heat loss etc.

Is this method of wall insulation ok? and will we get a decent job bearing in mind its grant funded and therefore free (to us) ?

 

[flameport]

After reading up on this method of insulating wall cavities, it seems it may not be such a good idea due to the wool possibly getting damp, condensation forming etc through cold spots in unfilled areas etc etc

All probably lies or people failing to understand what cavity wall insulation actually does.

Cold spots - since your entire outer wall is currently 'cold', adding insulation to it can't possibly make this any worse. In the unlikely event that an area was unfilled, it will be exactly the same as it is now.

Condensation is caused by excessive humidity inside the building, typically due to lack of ventilation and people misusing facilities (such as not using or even having extractors for kitchens/bathrooms, drying clothing on radiators, using condensing tumble dryers, cooking food in pans with no lids, not opening windows and so on).

For cavity wall insulation to get wet, water must be entering the cavity somehow. The main reason for this is the external wall being in a poor state of repair, or blocked gutters/pipes causing water to pour down the outside of the building.
The insulation might make the problem apparent sooner, but the answer is to fix the problem that already existed, not avoid the insulation.