Cavity Wall Insulation - a good idea?

LiveOnce

Hi there,

Is it a good idea to get cavity wall insulation in a concrete built semi-detached house built in the 1930's?

My parents suffer from heating issues and saw this as a potential solution. They will be in the property for next 20-30 years

The risk I have heard is it may cause damp? Is this a common problem? Or am I reading about rare cases?

Weighing up the risks and pro's is it a good thing to do?

forestwn6

We have had cavity wall insulation in a conventional build house for over 20 years with no damp issues.

[Deleted User]

I think the issue is geographical, damp is a common problem if you install CWI on a house that's subjected to persistent driving rain in an exposed location. That said, CIGA have a notorious reputation for not honouring the guarantee, so if you do have damp problems expect to end up funding the remedial work yourself.

Furts

Would a 1930s concrete built house have cavities? It may not. This is a specialised area, but my default answer to CWI would be no.

If you want to go ahead it is absolutely vital you seek a detailed, professional analysis. Do not rely on any CWI companies to give you a truthful answer. Do not rely on any CWI companies to do a thorough survey. Do not believe anything any CWI company tells without first researching 100% on everything.

The CWI industry is stuffed full of rogues, conmen, snake oil sales people and all round never do wells. You have been warned!

patman99

All newbuilds have CWI consisting of small round pellets coated with adhesive. This allows moisture to rise up and away.

As for concrete construction, is it concrete panels fixed to a steel framework?, or is it just a solid concrete wall?.

Even with a solid wall, there are optioms such as external screw-fixed insulation panels that can then be either rendered, or clad in external weatherboard, to make them fully weather-tight.