Party wall rock wool fill.

[TKH]

I am doing a loft conversion on a semi detached bungalow. It has already had cavity wall insulation done before I got the house but the party was still has a 4 inch unfilled cavity. Talking to a very friendly neighbour we are thinking of getting the cavity filled with rock wool to help thermal insulation and more so acoustic insulation. Does this sound sensible and how much would you normally expect to pay for something like this? Also could anyone recommend a company to do the job in the ts9 area? Thanks

 

[theprinceofdarkness]

Normally for cavity fill, holes are drilled in its face and the insulation blown/pumped in. Are you proposing to have holes drilled in your sitting room wall?
Frank

 

[TKH]

Normally for cavity fill, holes are drilled in its face and the insulation blown/pumped in. Are you proposing to have holes drilled in your sitting room wall?
Frank

the house is gutted and walls are stripped down to block work. as long as they could get there equipment in to the house any mess and drilling would be no issue. Do you think it's possible? Thanks

 

[freddiemercurystwin]

Why?

 

[^woody^]

There is a reason that party walls have an air gap. Something to do with sound IIRC.

 

[theprinceofdarkness]

You would save a very little energy because the inside of your neighbours house is likely to be very similar to yours. i.e. your inside temperature might be 20*C and the outside temp, 0*C, so you have 20*C temperature differential. Your neighbours house might be as cool as 16*C, so the temperature differential would be 4*C, so the amount of heat saved would be 1/5 compared to the front or back walls. However there could be a slight reduction in noise through the party wall.
Frank