1950s Cavity Closing

Anton · Post by **Anton** » Thu Jul 23, 2009 7:52 am

Hi everyone
My first post on this forum so just want to say hello

I’m half way through renovating my first house. It’s a 1950’s semi. I have worked my way around a lot of it but I’m a bit stuck on cavity closure around the windows. It still has the (as far as I can see) older style cavity closers which is basically mortar and slate. I have a friend who lives in same house on the road and all his walls around windows are constantly damp and black so I think now would be a good time to sort it out properly. However, I can’t find any cavity closers that will fit the gap (it’s around 30-40mm at the moment and very uneven) as half the cavity has been closed by brick from the inner wall. Photos below:

Is it worth cutting the brick back to open it up fully and fit a proper cavity closer or can I remove the slate and pack it full of foam? Any other suggestions would be great

leebwk · Post by **leebwk** » Thu Jul 23, 2009 12:12 pm

Hi,

I would basically cut out the slate and replace with 150mm dpc then foam in on the warm side to hold it in place, if you try and chop out the closers and part of the 3/4 bricks to expose the cavity you could be creating a whole lot of trouble

Anton · Post by **Anton** » Thu Jul 23, 2009 2:13 pm

That’s great thanks for the advice, this may be silly question but what stops me using just foam without the dpc? Does the foam not act as a dpc itself?

thescruff · Post by **thescruff** » Thu Jul 23, 2009 2:46 pm

Fold the DPC into a U, otherwise you will fill the cavity with foam

leebwk · Post by **leebwk** » Thu Jul 23, 2009 2:57 pm

Hi,
Foam is not a dpc and you must apply this only to the warm side ie inner leaf plus if you are careful this will not enter the cavity.
The foam will hold the dpc tight and also eliminate cold bridging

Anton · Post by **Anton** » Thu Jul 23, 2009 9:47 pm

Thanks guys will have a do