Renewing cavity wall insulation…

[HughF]

Is there any merit in having our old cavity wall insulation sucked out (chopped/blown fibreglass, it would seem) from our 2” cavity, and having it replaced with blown beads?

 

Forever home, happy to spend the money on it if it will improve things going forwards.

[SteamyTea]

3 hours ago, HughF said:

from our 2” cavity

That is your real problem.

Apart from maybe reducing air movement a little bit, as an insulation area, not really wide enough.

 

Probably going to have to do a mixture of internal and external insulation.

[LiamJones]

I’m in a similar situation, 2” cavity with old blown EPS beads. Considering replacing them with the new bonded EPS beads to eliminate any gaps and reduce future slumping. I will be adding 100mm EWI regardless. Not sure replacing the beads is worth it, not even sure on cost at this point? I guess once the EWI is on, it makes it harder to replace the existing cavity fill. 

[HughF]

3 hours ago, SteamyTea said:

That is your real problem.

Apart from maybe reducing air movement a little bit, as an insulation area, not really wide enough.

 

Probably going to have to do a mixture of internal and external insulation.

We'll fill the cavity up as the recent building work has highlighted some areas where the loose fill hasn't gone, then look at some IWI. Not keen on EWI on a terraced house.

[embra]

Hey @HughF, @LiamJones, did you come across any guidance on how to remove the existing insulation, or whether it would be possible to simply pump in more EPS to try and fill the gaps?

 

I have a similar situation in that we seem to have ~25 mm thick EPS foam boards in the cavity between outer brick and inner block, but  it doesn't look particularly well secured, or evenly distributed. I'm fairly confident it's not working as intended, so looking to find a way to improve things (or guidance to shift focus to internal insulation only).

[Temp]

I suspect the professional companies that do insulation removal have figured out a way.