Cavity Wall Insulation and Thermal blocks

Hi

Thinking of adding extra insulation to our 2001 home by getting CWI installed. Currently there is now CWI as the inner blockwork is thermal blocks. I have had one quote so far, looking to get a few more before making a decision. First company who came said that as my house is thermal blocks, the usual insulation they use cannot be used as it gets caught on the thermal blocks. So, I would need to use the beads instead. However, the beads are not subsidised by the government, so it would cost an EXTRA £250.

Is this correct? Waiting for another company to get in touch to see if they tell me the same thing. Just thought I would ask on here first.

Thanks

Rubbish.

Blown fibre works with thermalite blocks - in fact I had mine done last year under a subsidy, and the installer did not say a dicky bird

Energy Care UK Ltd - £99

Thanks for the reply.
He told me that the insulation gets caught up on the thin layer of insulation that is stuck to the thermal block. Said this does not allow the CWI to fall as it should and creates voids / pockets where there is no insulation. This creates cold spots and this is when damp can form.

ooops .... re-reading your post, you wrote "thermal blocks" and I read "thermalite blocks" which is a type of block

You need to clarify what these blocks are, and if we are talking about the same thing

There were (still are?) blocks available with a layer of insulation stuck to them, but I don't know how these can cause a problem.

From what the guy has told you, I can't see how the problems of voids and cold spots can be associated with "insulated blocks" as the fibre is still blown in under high pressure and drill holes are close enough together to fill the cavity. In addition, even if a void was left, if the blocks are already insulated then a cold spot issue is remote, so I would disagree with him on that

See what other installers say ... but don't mention the blocks yourself, let them tell you