Drafty gap round window - how to fix it?

[valve90210]

Hi All

Taking a slight break from the Lounge transformation as we haven't got babysitters for a little while, so we're concentrating on doing a few other jobs around the house.

One we want to tackle is the landing window. Having put up a sprung-loaded net curtain pole, we discovered that the half inch or so from the inside frame of the window has nothing more than a thin layer of plaster over it.

We discovered this as the fairly gentle pressure of the pole pushed a hole in the plaster. A further bit of gentle pushing enlarged the hole easily. This hole was letting in quite a draft so we've temporarily block it up with tissue:

We then found that the trim at the bottom was barely fixed in place and a little bit of effort removed it completely. Underneath it was a thin layer of mortar (?) again quite a draft was coming through.

A little bit of pressure and the mortar gave way to reveal there was also a gap underneath this too.

Excuse the terrible photo but this sort of shows the mortar pushed down into the gap.

I'd obviously like to sort this out as it looks a mess and is very drafty. I was thinking of chipping away the mortar/plaster all around the window so I can see exactly what the gap is looking like, then filling it with something, refitting the trim and then sealing with acrylic sealant.

Is this the best way of doing this? if so, what would be the best thing to use to fill the gap? I was wondering about expanding foam but it's not a huge gap so that'll probably be overkill.

Any thoughts very much appreciated.

 

[Mark A]

You could just fill the holes with expanding foam and put a PVC trim around the whole window and then seal the trim to the frame with a very thin silicone seal (But use acrylic to seal the trim to the plaster so you can paint up to the trim). This is how most window installers do it. Problem with using acrylic to seal the PVC frame to the plaster is that it will often crack away from the PVC window. You could try it first and then if it cracks put a trim around.

Here's one I did earlier (2004 )

Some don't like a trim around the window, but personally I think it looks nice and neat.

 

[valve90210]

That's exactly what I was thinking!

I did wonder if I could use normal filler as I have quite a bit left over from decorating the lounge, save me spending out on expanding foam...

 

[Nightglow]

Better to clear out mortar & use which doesn't expand too much to fill the the gaps.
All the windows here are exactly the same, a almighty draft removed a piece of trim top & bottom which was loose to reveal a lap gap, I also was able to push the nozzle up the sides from the top & bottom to fill any gaps.
Also took the oppertunity to replace all the concrete window cills with upvc ones.

That top hole I foam the frame, then use a filler on the hole in the plaster.

http://www.toolstation.com/shop/Exact+Gap+Foam+Hand+Held/p66044

 

[Nightglow]

Better to clear out mortar & use which doesn't expand too much to fill the the gap.
All the windows here are exactly the same, a almighty draft remove a piece of trim top & bottom which was loose to reveal a lap gap, I also was able to push the nozzle up the sides from the top & bottom to fill any gaps.

That top hole I foam the frame, then use a filler on the hole in the plaster.

http://www.toolstation.com/shop/Exact+Gap+Foam+Hand+Held/p66044

DELETE THIS ONE PLEASE.

 

[valve90210]

That looks like the perfect product as I was rather worried about expanding foam going everywhere having never used it before!

Would it be advisable to remove the plaster down the sides too as I don't definitely know how much gap there is and I don't really want to end up leaving an air pocket if I don't get foam in everywhere to fill it?

I'm thinking fill the gap with the foam, then filler to get a nice level finish for the trim to go over. Stick the trim with no nails or something similar. Then seal it all up with nice white acrylic...

 

[Nightglow]

No, I would only remove one or two small patches, only need a small hole,, just enough to slide the nozzle up & down the gap between frame & wall, sides, top & bottom. I usually do the holes, twice the length of the nozzle apart, I find it's virtually guarantee to fill the whole gap that way, push nozzle up or down the gap, squirt or two as you slowly pull the nozzle out.

Go easy with the foam, too much you & you might dislodge any internal trim around the window, if it's been poorly fixed.

And wear the gloves which come with it, or some others, as the foam is a swine to get off your hands.

With the trim use a non solvent adhesive, some sealants will also stick the trim.

 

[valve90210]

That's good thinking there!!

Small holes it is then, also minimises the amount of filler I'll need to use.

I'll probably remove all the mortar at the bottom as it's just crumbling away anyway, should give me a chance to get a feel for how the foam works before I start on the sides and top...

Good point re the trim, don't want to end up meltng it! lol