I ve seen a number of houses with problems even though they re insulated with spray foam.
Foam cavity wall insulation problems.
Reinsulate with dense packed cellulose still my personal.
So here s the part that sucks for me what has to be done to fix the problem.
Spray foam insulation is a better insulator than mineral wool loft insulation as you need less of it to get the same insulating effect.
Remove the foam to reinsulate.
In some cases the damp and mould resulting from cwi can cause health problems or exacerbate existing conditions particularly respiratory conditions.
When we went undercover to investigate the quality of insulation suitability inspections in 2011 our findings suggested that you can t always rely on assessors to carry out thorough inspections or warn of potential damp problems even those from big brands such as marks spencer npower and tesco.
Spray foam isn t thick enough.
Until the recent fad for cavity wall insulation took hold the only times rainwater penetration was a problem was when the steel wall ties were dirty with mortar droppings and or built sloping downwards from outer leaf to inner leaf or the cavity itself was blocked at low level with mortar droppings or other debris.
What is a cavity wall.
Some spray foam insulation sets rigid and can also be used to help reinforce roofs that are suffering from nail fatigue when the nails used to hold slates in place rust or support cavity walls where the wall ties are failing causing cracks and bulges in walls.
Remove enough siding to jimmy the foam out probably 2 3 pieces per story per wall cavity.
If your cavity is full of insulation and no moisture water or water vapour is getting into the cavity then you re probably going to be fine.
Damp walls as one of the most well known problems with cavity wall insulation damp is an issue that no homeowner wants to see.
So how is cavity wall tie failure linked to problems with cavity wall insulation.
However if moisture is getting into the cavity the insulation can hold that moisture against the metal wall ties and speeding up the rusting process.
Spray foam installers missed some of the air leakage sites.
Expanding foam insulation has increased in popularity as the manufacturers have praised its uses and abilities and its applications have reached to include cavity walls.
In order of prevalence here are the problems i ve seen with explanations following the list.
Find out if your home s likely to be affected.
Yes you can use expanding foam insulation in cavity walls.
Incorrectly installed cavity wall insulation causes water to seep into a property s walls causing structural problems and damp patches that may also manifest into mould.
Better yet remove it.
Cavity wall insulation can cause damp.