Detail where cavity wall joins single skin wall?

[oly]

The drawing shows the new cavity wall (full fill insulation in blue) coming down to join an existing single skin utility room (red).

Any ideas best way to join the inner skin blockwork to the single skin?

If I straight join it I create a 'thermal-bridge'. If I finish it say, 100mm away from the single skin it isn't tied in.

Anyone know how to deal with it?

Is there any product made to deal with this situation?

Untitled

• oly
• 10 Feb 2015
• 1

 

[jsa242424]

Hello Oly

The cold bridge is from the warm air in the new room via the existing wall (red) to the exterior. Not joining your new wall to the existing wall (red) does not in any way help the situation, so I would recommend making a conventional join (walll ties etc).

You could beef up the insulation of your new wall by using Gyproc thermaline insulated plasterboard or similar. You could consider lining the inside of your single skin (red) wall too which would (at a price) treat that cold bridge.

I had a similar problem when I rebuilt the front wall of my bungalow. The party wall seems to run through to the front without a cavity.

In my case I lined only the outside (new) wall. I do get a small amount of condensation and mould at the top of the party wall which has to be cleaned from time to time.

I had to use the gyproc thermaline on my new wall, because without it I could not have met the building regs for heat loss.

Julian