Damp Problems

[fredrika]

We had insulation pumped into our house exterior walls 2 years ago. This was under the free scheme offered by the government. Now we have damp problems very severe in our hallway. My husband was never a fan of this method as rain can travel across cavities on the wall ties. He was assured that the materials used prevent this. Are this company responsible or shall we have to pay to correct all this, bearing in mind this could happen again. If anyone else has experienced this I would love to read their views. Thank you.

[The Builder]

Contrary to what a lot of people think, Fred, cavity fill doesn't result in damp transfer. Dirty wall-ties can do it though. Although if they were that bad, I'm surprised it didn't show before.

To be fair to the Company, they can never know just how good or bad the wall-ties are when they install. It's very rare to get this with cavity fill. It's usually some other cause.

What's the outside wall... brick?

[riptide]

I was going to have cavity wall insulation, had an inspection by the surveyor, he said there was rubble at the bottom of my walls that would need to come out before the insulation was installed, otherwise damp may occur. Never did have it done, as several bricks would have to be removed from bottom of brickwork and was not sure if they could be matched or what sort of mess would occur. Good luck with sorting it out.

[buildersmate]

As TB says, the way this happens is across the mortar that sticks to the brick ties. Brickies are supposed the hang wood gap fillers into the cavity as they build so the mortar lands on them. They then pull the spacers up periodically during work to remove the mortar. Some don't bother.
When the cavity is filled with insulation, no air circulates around the damp water-laden tie and the moisture wicks more easily to the inside.
I was an early adopter of cavity insulation and a house filled in about 1985 first time. In the winter damp occurred. The company dealt with it by spraying the outside brick wall with Aquaseal, a clear water-proofer. It solved the problem.
Don't forget we've had a he'll of a wet winter and driving rain into the wall is unlikely to be experienced like that again for a while.

[fredrika]

Thank you everyone for the sensible sounding answers. We feel the answer is spraying the seal on the walls. I look forward to this being a solution.