Cavity closing in the early 60's - Anyone had experiences?
 

I have one of those wonderful house that dont have patio/french doors. I'm therefore going to be ripping out a window in my dining room and installing some sliding-folding (concertinaing) doors in the near future. As I will be chopping down the portion of brickwork below the current window cill, it will result in me having about 1.2m of cavity exposed either side. This in itself is not a problem as I was going to stick some Thermabate (or similar) cavity closer in there.

My question is this:

The current window reveal obviously has the brickwork returned to close off the cavity on either cheek as in the 60's insulated cavity closer were not even dreamed of!. So before commencing, would you expect the cavity be closed off by:

a. brickwork fully bonded to both internal and external skins
b. bricks bonded to internal skin with a full height vertical joint where it butts the external skin
c. brick bonded to external skin with a full height vertical joint where it butts the internal skin (unlikely as there are no internal vertical cracks which you would expect)

In b & c above would they have potentially installed a vertical damp membrane/course/barrier/goo-paint to stop moisture penetrating straight through from outer to inner skin?

Finally, I was going to chop out these bricks currently bridging the cavity anyway, allowing me to install a full height (2.1m) cavity closer. Is this advisable, worth doing or to be avoided at all costs?

N.B. I won't be grinding the reveal down, but toothing out and making good. Don't think the missus (or the little one come to think of it) will like a house full of brick dust caused by grinding! ;-)

Cavity closing in the early 60's - Anyone had experiences?
 

Cordless Crazy wrote:
I have one of those wonderful house that dont have patio/french doors.

snip

My question is this:

The current window reveal obviously has the brickwork returned to close
off the cavity on either cheek as in the 60's insulated cavity closer
were not even dreamed of!. So before commencing, would you expect the
cavity be closed off by:

a. brickwork fully bonded to both internal and external skins

defnitely not


b. bricks bonded to internal skin with a full height vertical joint
where it butts the external skin

correct.

60s/70s era would have been a bitumastic felt (150mm wide IIRC but
could be 100mm/4inch??) dpc against the outer wall and cut brick or
block closer turned in from the inner skin plus wall ties inboard along
the wall not too far away

HTH

Cool. Thats wot I suspect. Glad I was thinking along the right lines.