Sealing internal gaps between new plaster and windows

I have just has new windows installed and the walls plastered. All looks good apart from a gap surrounding the windows and doors between the UPVC windows and new plaster.
The window guy tells me the plasterer should have plastered right up to the windows and the plasterer says the window installer should fill the gap with some cork material. Either way it looks like i am going to have to do it.
Could someone tell me the best method and product to use in this sitiuation. I believe it has to breathable???
Thanks

Hi, diamnot,
You don't say if the gaps are small and regular, I wonder how this has happened? I agree with the installer (on the face of it).
I should think any of the propriety fillers would do, but consider decorators filler first, as it is slightly flexible. (when set)
I don't see any reson why it should be breathable.
I would check first there is no movement of the frames
Decorators filler comes in tubes and is applied with a gun.

They are normal size gaps, about 4-5mm. Does that make a difference?

No, that sounds ok to fill, probably just shrinkage
wait to see if any one else offers something before rushing off to B+Q.

Thats all sounds ok then..... but i am more of a wickes man myself!!!

diyiamnot said:

The window guy tells me the plasterer should have plastered right up to the windows

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Yes he should have, why didn’t he? I always use a stop bead against the frame it makes plastering the reveal a doddle & gives a nice straight line against the frame. Any shrinkage around the frame can be rectified by a bead of decorators caulk (don’t use silicone as paint wont stick to it) but this doesn’t usually happen for a few months & will only be a couple of mm at most, not 5mm!

diyiamnot said:

and the plasterer says the window installer should fill the gap with some cork material.

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That’s a total load of carp!

I think i should try and explain where the gap is ......

The gap is around the window and the wall. Imagine if you have a two squares one large and one small. Place the small square inside the large square and then you will have a gap around the outside. Basically my window was slightly smaller than the exsisting hole thus the gap.

Dont think in that sense it is as easy to fill the gap with plaster?

The window should be made to fit the outside brickwork with a 3-5mm gap not the internal plaster which can be up to 16mm thick! Packers are used either side of the fixing screws & if they’ve made the windows the correct size, all that should be needed on the outside is a bead of silicone to seal the frame. You should not be able to see a gap all around the frame on the inside, if you can, either the windows have been made too small or the plasterer didn’t line the reveals before skimming, was the plaster completely removed on these?

Hi, All,
This starts to sound interesting, and there are various possibilities I didn't think of.
obvious question, but have you looked at the window from the outside?
I know I suggested this before, but, picasa is good for posting pics, and a picture is worth a thousand words.
chessspy

The windows look great from the outside and fit nicely, with silicone sealant round the edge.

The plaster was not removed. The plasterer then skimmed over the top of the exisiting old plaster.

Whats the solution then? Get the plasterer to fill the gaps or get the window installer to fill the gaps?

Or for me to put some decorarters chaulk in the gap?

My vote is to put it on to the plasterer, however if you get no joy,
I should think you could just caulk it.
If the windows fit well from the outside with a weatherproof sealant, then that should do the trick.

diyiamnot said:

The windows look great from the outside and fit nicely, with silicone sealant round the edge.

The plaster was not removed. The plasterer then skimmed over the top of the exisiting old plaster.

Or for me to put some decorarters chaulk in the gap?

Click to expand...

Well I'm at a loss to understand what's gone wrong without actually seeing it; when the old frames are removed, the new ones slot into the brickwork opening from the outside & will either butt up against or be very close to the edge of the original plaster; all that then may be required is to fill the gap with plaster/plaster based filler or apply a bead of caulk around the inside against the frame. The frame should always be below the level of the plaster inside & I can’t visualise how you can have a gap you can see around the frame on the inside but not on the outside. One trick that’s used if the window has been made too small is to fill the gap with expanding foam & stick a UPVC trim (quadrant or D nose) around the outside of the frame with silicone, butted up against the brickwork to hide the gap. It looks OK for a while but it doesn’t alter the fact that the window has been made too small for the opening & it may mean the frame is not very secure; makes a nice snug home for bugs, ants & other crepies to colonise though!

5mm is too much of a gap to fill with another skim (although I suppose he could skim it twice!) or fill with decorators caulk; it shrinks back & will always notice. I would stick some plasterboard around the reveal to take up the gap & re-plaster; do you have the same problem at the bottom or is a sill not yet fitted?