Big gaps above windows

dr_bogenbroom

I have 2 small downstairs rooms each with a small uPVC window - one is a cloakroom and the other is a guest toilet. This is the only single storey part of the house (not sure if there is a name for this type of design) pictures below:

Ignore the moss in the roof - it’s getting cleaned tomorrow! These rooms are always freezing and I figured this was because I don’t believe this small roof has any insulation but today I discovered big gaps above the 2 windows: 

Can I fill these gaps and if so with what? There are no eave vents on this small roof section so I don’t want to block something up that’s keeping away condensation. 

Thanks.

MikeJXE

Silicone sealant but if the gaps are quite wide get some pvc plastic quadrant to stick in the corner with said sealant 

dr_bogenbroom

MikeJXE said:

Silicone sealant but if the gaps are quite wide get some pvc plastic quadrant to stick in the corner with said sealant 

Thanks will look into this. Would expanding foam not be advisable?

Beeblebr0x

dr_bogenbroom said:

MikeJXE said:

Silicone sealant but if the gaps are quite wide get some pvc plastic quadrant to stick in the corner with said sealant 

Thanks will look into this. Would expanding foam not be advisable?

It can be difficult to control the flow of foam as it expands. It will also be messy to clean off the excess. Far better to use silicone sealant/quadrant as previously advised.

flashg67

If they are deep gaps I'd be tempted to use expanding filler first, or foam gap filler backing strips (google them!) then frame sealant

ThisIsWeird

The problem with exp foam is that it's tricky to control, and also doesn't give you a neat finish, so frame sealant would be needed afterwards in any case. So, yes, frame sealant is the best thing to use straight off.

I personally wouldn't use silicone sealant, as paint doesn't adhere to it - but it's otherwise good stuff.

The easiest type of frame sealant is water-based stuff, as excess can be wiped off with a damp cloth. By all means inject a good-sized bead into the gaps first, as well as leave a neat bead on the outside. Fugi-type rubber finishing tools will work on it - I've tried - and will give a professional, bevelled, finish - tho' it'll likely shrink a bit as it dries.

If you want that room easy to heat, it'll really need insulation adding to the wall. 

Adhering quadrant beading as suggested above it also a neat method. Again, inject the adhesive/sealant into the gap first, and then a coat on each contact side of the beading, and press into place - wipe away extruded excess.

FreeBear

Had similar gaps along the tops of some of the windows here - Replacement wood framed DG dating from the mid 1970s. When they were replaced with uPVC a couple of years back, I had lengths of timber fixed to the (wooden) lintels, and the frames screwed to the timber.Unlike your windows, I had ~200mm of trim above mine to hide the extra timber.With your window, I would see if the soffit can be removed. If it can, glue/screw a length of 3x2 to the lintel. Run a generous bead of sealant along the top of the frame first. Then put a couple of screws up through the top of the frame in to the new bit of timber. This will stop the frame from rattling around in high winds. Once everything is secured, squirt some expanding foam (use a gun) in to any gaps from the inside.

Being on the first floor, access is not going to be easy... It may pay to ask a local window fitter to do the work (or a window doctor). Slapping a bit of uPVC trim on or just squirting loads of expanding foam in to the gap is not a long term solution.

dr_bogenbroom

Thanks all - I’ve never heard of quadrant before and looking on Google brings up a few different looking options… what kind would you suggest?

MikeJXE

This should do it 

Wickes PVCu White Quadrant Window Trim - 17.5 x 2500mm