Installing UPVC Door

aidanki

I have to fit a UPVC Door into a cavity wall. The Cavity wall was built 40years ago but no door ever installed. The space which was left in the blockwork is 7ft 1" high and 3ft wide, 3-4" cavity. When the doorway was plastered up the remaining gap is 7ft high X 3ft wide. Its nice and square.

I was wondering what size of door should I be ordering here.

It would be quite easy if it was into a solid wall, get a door as follows 6ft 11.5" high and 2ft 11.5 wide and put screws into the solid wall sides.

10-10-20

I'm not sure when you refer to the cavity in this way. Is this a solid-block double-leaf construction with a cavity OR constructed using one leaf of cavity-blocks? Back in 1980, I think they were starting to use double-leaf over cavity-blocks, but need to know which is which.

Is it going to be an external door, or internal? Is there a lintel fitted?

It sounds like you just need to fit the door to the existing gap and secure it with concrete screws, but I take it that you have concerns around the purchase within the block and plaster, right?

aidanki

https://www.boards.ie/discussion/comment/117825074#Comment_117825074

The wall is built from 2 X 4"blocks on edge, and the cavity between them, (this is the solid block double leaf you are referring to I think) Its an external door on the shed beside the house. Yes there is a lintel fitted. Timber is all that was used to cover off the cavity, I guess it was planned to fit a timber door at some stage but it never materialized so step 1 is to pull that out of it.

External door.

10-10-20

If it's all plumb as you say, then I would probably size the door for the opening in the external leaf (minus at least 5mm each side), then knock out the wooden frame before fitting. Fit the frame into the external leaf. You can usually pick the depth of the PVC door jamb to suit. Run some DPC through a mortar bed under the jamb (sloping out if possible) and also a vertical DPC if you're going to close the cavity with plaster/mortar etc.

When I was replacing my PVC windows yesterday I just sized it to the exact dimensions of the existing PVC and knocked out the internal lintels so that I can push in the new frames and then replace the lintels with insulated plasterboard. The proper window/door expanding foam makes this all very easy to seal off.

10-10-20

I meant to type reveals above and not lintels! - anybody who knocks out lintels to install a window is clearly looking for trouble. 😝