No point in injection insulation into hollow block/cavity block wall?

ReadySteadyGo

SEAI, say if you are going to insulate internally, that there is no point, in injecting, as most of the heat is lost via thermal bridging on the solid part of the hollow brick, so filling the hollow part does little. I was surprised with this.

Does anyone have any experience on this?

I have all the internal of my external walls exposed back to block (in prep for insulated drylining). So now would be an easy time to pump them from inside the house, without turning the outside of the house into swiss cheese.

http://www.seai.ie/Power_of_One/FAQ/Insulation/insulating_Hollow_block.shortcut.html

Thanks,

Sean.

bbam

It makes perfect sense, the % of the wall with coldbridges is too great to have any effect on cold transfer...
Why not spend more money on greater thickness of insulation on the inside where you know it will work...

aujopimur

Why have you stripped the walls back to bare blockwork?.

michael999999

why are the goverment giving massive grants towards it so?

Radiotower

The purpose of insulation is to stop heat from escaping through the walls so your internal insulation should do this - the amount of heat that gets through the internal insulation should be minimal and therefore the injected insulation would have very little to do and would not be cost effective.

Its a matter of one of the other really - personally I'd go for the internal since you seem to be prepared for it with having the rooms stripped out and are going to have them re-plastered either way.

Obviously some home-owners cannot have the disruption of doing the internal insualtion and thats why they go for the injection - thats why the government have it grant aided.

bbam

Pumping insulation into a wall constructed from cavity blocks is very different to pumping the cavity of a standard double leaf construction...

If the wall is constructed from cavity blocks I doubt injecting the insulation would do much good..

Carlow52

aujopimur wrote: »

Why have you stripped the walls back to bare blockwork?.

+1
very curious

ReadySteadyGo

Why Stripped back.

House is a complete refurb job.

Reclaim space to limit room size loss. Especially on stairs wall.

Concern about fixings though 10cm of new board, and 2cm of old board before getting to the wall. (see my other post in DIY).

And I might fill in some mortar now that I can "see" drafts.

ReadySteadyGo

Thanks for all the feedback. It seems everyone agrees with the seai on this one. I will continue with the dryline insulation only!