Doorway..laying a slab

Hi

Building a conservatory: doulble wall to 600mm

Question: when laying concrete slab..... for a conservatory.. what is the method for bridging both walls(ie the cavity) over the doorway?

Thanks

R
Reply to
ramrod
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I just used some old roof slates when I did mine. Worked fine.

mark

Reply to
mark

ramrod coughed up some electrons that declared:

You can get "cavity closer" which is a lump of insulation designed to press into the cavity by a couple of cm, backed with a sheet of PVC which wholly covers the "damp" side leaf and hangs over the dry side leaf by a couple of cm.

Make sure you measure the cavity gap before going to the builder's yard - though there is a trimmable universal version available.

One old way was to return the inner leaf (dry side) bricks into the cavity (90 degree turn) so that they were almost touching the outer leaf. Length of standard DPC over the end where they nearly touch the outside. Use DPC over all edges of the outer damp leaf between frame/cill/step and leaf.

The former has the advantage that it maintains cavity insulation better.

Cheers

Tim

Reply to
Tim S

Ramrod I appreciate you are getting useful answers but I find your query confusing and wonder if you are getting the answers you want.

I read the answers as dealing with the cavity at the door lintel, but you seem to be asking a question about the cavity at the door cill, but say "over the doorway", which doesn't fit in with "...laying concrete slab...".

Rob

Reply to
Rob G

The cavity in a cavity wall goes below the DPC......

Reply to
Phil L

Thanks Tim .... you answered my question Many thanks for taking the time.

Reply to
ramrod

Rob G coughed up some electrons that declared:

Not really an expert - but I had a window cut down into a doorway, which is when I saw the trick of returning the bricks towards to outer leaf.

It leaves me with an open cavity on the lower half of the door, including threshold.

I'm going to leave the upper section alone and use cavity closer over the lower half of the sides. Undecided on the cill - might wack the cavity closer along there too, or just DPC both inner and outer leafs. I'm putting a cill over which will happily bridge the cavity, support wise.

Not sure how conventional this is, but it works for me (prevents damp bridging - we won't get too hungup on cold bridging the cavity insulation because there are many potential cold bridges in this house anyway)

Cheers

Tim

Reply to
Tim S

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