Cavity Wall and Plastering question.

[bon98uk]

Hi, I'm new to this forum. I hope someone can help I have following 2 questions.

1) I have had a Patio door removed and a window fitted to replace it. This has involved bricking and blocking around and under the window. The room is plastered with base coat and top. The plasterer wants to fill in the area around window with plasterboard and skim. I am not happy with this as I would prefer it to be 'as the original'. Anyone know if I should hold firm or go with his recommendation?

2) At same time I had a window taken out and french door inserted. This meant cutting an opening beneath the ex-window to take the bottom half of door. The door reveal is currently revealing the wall cavity. The old window reveal has this cavity bridged with blocks to close. The plasterer wants to cover the unclosed cavity with plaster board. I beleive this should be bricked or blocked closed before being plastered over. (I am not happy about just covering an open cavity with a piece of plasterboard.
Any comments on proper or best practice?

Sorry explanations seem long hope someone can assist.

best regards,

bon

 

[rangersman]

Hi, I'm new to this forum. I hope someone can help I have following 2 questions.

1) I have had a Patio door removed and a window fitted to replace it. This has involved bricking and blocking around and under the window. The room is plastered with base coat and top. The plasterer wants to fill in the area around window with plasterboard and skim. I am not happy with this as I would prefer it to be 'as the original'. Anyone know if I should hold firm or go with his recommendation?

2) At same time I had a window taken out and french door inserted. This meant cutting an opening beneath the ex-window to take the bottom half of door. The door reveal is currently revealing the wall cavity. The old window reveal has this cavity bridged with blocks to close. The plasterer wants to cover the unclosed cavity with plaster board. I beleive this should be bricked or blocked closed before being plastered over. (I am not happy about just covering an open cavity with a piece of plasterboard.
Any comments on proper or best practice?

Sorry explanations seem long hope someone can assist.

best regards,

bon

My experience is predominately timber frame, but I can offer the following:

1) I don't think this approach would matter too much, but I (like you) would prefer to see the plaster built up from the brick

2) The cavity needs to be closed and the reveal plastered as above. Without closure I suspect you would get cold bridging and possibly damp

No doubt one of the "brickies" will give you a response based on better experience.

 

[Darkrob_DIY]

Usually the cavity will be closed by either a series of blockwork with a vertical DPC positioned between it and the external leaf to prevent any moisture from getting through.
However a much simpler option would be to use a proprietary cavity closer which incorporates DPC and insulation, and is very easy to fix.
I would advise you to use a cavity closer such as these;

http://www.buildingdesign.co.uk/arch/rmcpanel/rmcpanel.htm

As if you simply plasterboard over it, you will have problems with damp migrating from the external leaf over the plasterboard and into the building.

Hope this helps

R Critchley

 

[Richard C]

I would insist he replicates the original, if a plasterboard ‘patch’ is used you may get cracks due to differential expansion. Make sure he chips the edges of the old plaster away to create a rough, uneven edge as this also helps prevent cracking where the new & old plaster meet.

Insist he uses a proprietary cavity closer (may be tricky with the new door in place!) these are a lot easier than messing around with blockwork & a vertical DPC. You could use plasterboard to line the reveal (over the closer) & then use a finishing plaster depth corner mesh to tie it in with the wall face.