What should first (top) floor UPVC windows be attached to at the top?

[Beginerz]

We are shortly due to have old windows replaced with UPVC. The plaster above the window recess (rear first floor bedroom) looked loose so I decided to tap a bit out to check all looked ok behind it.

I am a beginner DIYer (first home project) and found what looks like one length of timber above old wooden window frame and then a hollow gap where I can see through to roof soffit/facia area.
Above the window recess plaster itself is one timber, presumably when they plastered to wooden plaster frames, and a gap to the timber above the old wooden window frame.

Is this as it should be in order for a new window to be fitted?

We will be having replastering done later on.

Thanks all.

 

[noseall]

You are unlikely to find much to mechanically fix to above the soffit. You'll have to rely on sealant. Mechanically fix the sides. Use foam from the inside.

We always provide fixing points in our soffit space....

Bolt1

• noseall
• 27 Apr 2022

 

[Beginerz]

You are unlikely to find much to mechanically fix to above the soffit. You'll have to rely on sealant. Mechanically fix the sides. Use foam from the inside.

We always provide fixing points in our soffit space....

Thank you.
Regarding the plasterboard, does there ideally need to be anything else there behind it to support it or would there normally be a gap behind it?

 

[23vc]

The timber is a lintel supporting a couple of courses of bricks up to the wall plate on the inner skin, and the gap is the cavity (cavity wall) and should be insulated

 

[Beginerz]

The timber is a lintel supporting a couple of courses of bricks up to the wall plate on the inner skin, and the gap is the cavity (cavity wall) and should be insulated

Thanks. The timber above the window frame itself just has a gap above it into the space above the soffit so surely trying to insulate this would be difficult as the insulation would be in the soffit space as well as the cavity??

 

[23vc]

Should probably be loft insulation above it then. Any sign of any?

 

[Beginerz]

Should probably be loft insulation above it then. Any sign of any?

[Post edited with new information]:

I don't think the space above the window frame/recess goes into the loft area.

I have screenshot these photos from our survey:

Insulation can be seen at extreme edges of loft but this can't be seen above the plasterboard in front of the window frame.

There must be a cavity type area above the window but the cavity on the outside facing part is just open straight into the area above the soffit?
Should this be insulated?

Also can anyone point out what type of insulation this is and is it likely to be an asbestos containing type or is it likely to be safe?

Thank you.

 

[23vc]

The loft insulation should be continuous into the wall cavity, ideally but obviously isn’t in your case. I’m still not sure what’s above the timber beam, unless the beam’s the wall plate that the rafters bear on to. But I’d just insulate wherever you can from the window recess as best you can.
That loft insulation is the fibre wool type, not asbestos, but makes you cough so wear mask if disturbing it much

 

[Beginerz]

The loft insulation should be continuous into the wall cavity, ideally but obviously isn’t in your case. I’m still not sure what’s above the timber beam, unless the beam’s the wall plate that the rafters bear on to. But I’d just insulate wherever you can from the window recess as best you can.
That loft insulation is the fibre wool type, not asbestos, but makes you cough so wear mask if disturbing it much

Thanks.

Is there actually a wall cavity here, as from the third picture I've posted at the top of thread, it can be seen that the window touches the soffits on the outside?
I understand there are a few courses of bricks above the window recess on the inner skin but directly opposite this within what we are referring to as the wall cavity is simply the hollow space behind the soffits and fascias. Would these hollow spaces behind the roof soffits and fascias normally be insulated?

 

[23vc]

window is fixed to outer skin, and touches soffit, probably covers part of the cavity too
Then you’ve got a cavity, as it’s deffo a cavity wall
Then you’ve got your inner skin
Soffit space doesn’t need insulating, but any of that space you can see from inside, does

 

[Beginerz]

window is fixed to outer skin, and touches soffit, probably covers part of the cavity too
Then you’ve got a cavity, as it’s deffo a cavity wall
Then you’ve got your inner skin
Soffit space doesn’t need insulating, but any of that space you can see from inside, does

Ok thanks and apologies for my confusion.

The part I am struggling to understand is that I can see directly through to the soffit space as there is only the one piece of timber above the window (which the window is fitted to) between the gap in the plasterboard and the soffit space. If for example foam was to be sprayed behind this plasterboard, I would think it would go straight through into the soffit space as there is only that one narrow timber in between, and so the space would effectively never be filled.

I could knock away some more plasterboard above the window recess and adhesive some rigid insulation above. If I pushed rock wool etc in I'd think it would just fall away straight into the soffit space as there's nothing forming a cavity on the outer skin here as it appears to be just one timber above the window frame and then soffit space.

 

[23vc]

Yep, I’d put rigid in then. You just need to think of the room as needing to be enveloped with insulation, with no uninsulated part apart from the window itself

 

[Beginerz]

Yep, I’d put rigid in then. You just need to think of the room as needing to be enveloped with insulation, with no uninsulated part apart from the window itself

Makes you wonder how much behind the plasterwork in a lot of houses is just left uninsulated simply because nothing has been knocked back to open up the cavities. I suspect there's no vertical DPC either side of the first floor window but without knocking off the wall plaster I'd never know and it's probably existed like this for decades.

 

[23vc]

Most of them probably. But in your case adding it makes sense, as it closes the gap and reduces a bit of heat loss/cold spot. Your walls (assuming 60s?) wouldn’t have been insulated originally either, just a clear cavity.

 

[robinbanks]

Thank you.
Regarding the plasterboard, does there ideally need to be anything else there behind it to support it or would there normally be a gap behind it?

Ideally there would be insulation behind it rather than a gap; if you're talking about the vertical sides to the window, insulation backed plasterboard bonded on with foam would be best. For other areas, if there is a chance it will be exposed to draught, rigid foam may not be best. Though wool doesn't perform as well a PIR/PUR in a lab, it is easier to fit and deform around awkward shapes leaving less opportunity for draughts to reach the plasterboard. Of course, rigid would work well if it can be guaranteed sealed up to be draught free but doing so can be really fiddly and time consuming in restricted space