Awkward tight gap at window sil

limnam

I have a very awkward gap under a bedroom window sil i was looking for any tips on.


I originally was going to try getting some spray foam but the gap is not wide enough to get the foam in. The other problem is it's a very deep gap so just cauking at the won't give any insulation to the window

Calahonda52

any pictures
maybe widen the gap till u can get in the foam

Lumen

PU foam can do pretty small gaps if you use a proper metal gun rather than the plastic straws.

You just have to wind the flow rate right down.

limnam

sorry yeah should have uploaded a pic


hard to get at it with decent light

_Brian

Cauk and paint it

Turbohymac

If theres possibly of any dampness from outside maybe tec7 good quality silicone

_Brian

Turbohymac wrote: »

If theres possibly of any dampness from outside maybe tec7 good quality silicone

If dampness is a problem I’d be sealing on the outside surface and keep damp right out where it belongs. This is a very inside surface and no damp should get this far.

Turbohymac

Well caulk is ok but that crack is probably slightly increasing with time..caulk will only crack and flake again whereas silicone would allow for very slight movement..
In any instance I think the op.needs to investigate further as to what's causing this crack..a stitch in time and all that

limnam

_Brian wrote: »

Cauk and paint it

The problem with Cauk is the gap is very very deep so won't help with any insulation

listermint

With what insulation ?

Its under the windowboard , If heat is being lost there then filling it wont make any impact. For example if you decided to remove the window board entirely you should be able to and still have a warm room. The sealing should be done at window itself. The windowboard is not an insulator. its just a finish

limnam

listermint wrote: »

With what insulation ?

Its under the windowboard , If heat is being lost there then filling it wont make any impact. For example if you decided to remove the window board entirely you should be able to and still have a warm room. The sealing should be done at window itself. The windowboard is not an insulator. its just a finish

ah ok


so just do the front and not fill the full gap ?


grand job

limnam

Turbohymac wrote: »

In any instance I think the op.needs to investigate further as to what's causing this crack..a stitch in time and all that

I think it was just poorly fitted originally.

Calahonda52

limnam wrote: »

I think it was just poorly fitted originally.

No, It looks like shrinkage as the sill board fully dried out, very common

dok_golf

_Brian wrote: »

If dampness is a problem I’d be sealing on the outside surface and keep damp right out where it belongs. This is a very inside surface and no damp should get this far.

absolutely

_Brian

I’d be hesitant to put very much in round a window like that.

You could easily impede on the detailing and result in a damp or cold spot due to bridging or damage to dpc.

Check outside to ensure there is no opening for moisture to enter, seal with a good quality product if there is. If your seeing a significant corresponding crack on the outside maybe have a professional check out what is going on.

Then I’d just close up the interior gap with cauk, silicone or something similar. Choose something that remains flexible so if the opening does grow a bit more then it will stretch with the opening.

limnam

_Brian wrote: »

I’d be hesitant to put very much in round a window like that.

You could easily impede on the detailing and result in a damp or cold spot due to bridging or damage to dpc.

Check outside to ensure there is no opening for moisture to enter, seal with a good quality product if there is. If your seeing a significant corresponding crack on the outside maybe have a professional check out what is going on.

Then I’d just close up the interior gap with cauk, silicone or something similar. Choose something that remains flexible so if the opening does grow a bit more then it will stretch with the opening.

There's no dampness and doesn't seem to be any draught coming in.


The reason I started looking at it was due to the outside noise. The "sound" is like the window is "open" which is why i started looking at getting the foam under the sil.

listermint

limnam wrote: »

There's no dampness and doesn't seem to be any draught coming in.


The reason I started looking at it was due to the outside noise. The "sound" is like the window is "open" which is why i started looking at getting the foam under the sil.

These statements conflict

limnam

listermint wrote: »

These statements conflict

Not sure how to explain it, it seems outside noise sounds similar to if the window was open. But the window is not open. so I thought the sound was coming in through the gap if that make sense.

massy086

limnam wrote: »

Not sure how to explain it, it seems outside noise sounds similar to if the window was open. But the window is not open. so I thought the sound was coming in through the gap if that make sense.

If there is A opening part of the window.check if it is making a good seal when closed.you may need new seals or new hinges