Opinions roof above bay window

[80sman]

Please see attached photos showing roof above bay window.

My thought was to seal all the gaps up with silicon, then use celotex to insulate with expanding foam to hold it in position.

Use some new damp proof membrane under that and finish with some new 12.5 plasterboard.

My worry is would that be sealing it too much, does the timber need to breath?

And would it be better to use the green plasterboard than ordinary grey?

Thanks.

Pics attached

IMG_20181127_152006

• 80sman
• 27 Nov 2018

Gaps

IMG_20181127_151945

• 80sman
• 27 Nov 2018

Gaps around window board

IMG_20181127_151935

• 80sman
• 27 Nov 2018

Vapour barrier was nailed to wood frame. Plasterboard had started to sag

IMG_20181127_151923

• 80sman
• 27 Nov 2018

Distance shot

 

[80sman]

I should probably of mentioned that it's just a lead roof on top of the ply.

 

[Ian H]

I’d foam 50mm between the joists, screw a full 25mm layer under, then plasterboard.

 

[bobasd]

thats a poor Pvc bayinstallation.

can you post pics showing the lead roof an the left hand side (from inside) of the fascia?

besides the insulation issue,why have you removed the bay ceilin?
what kind of steel lintel(s) has been installed?
no edge support or backing showing - plasterboard needs supportin at the edges.
presumeably ther are two posts in the bay?
i can see daylight at the left hand side fascia level mitre

 

[80sman]

I've realised I've named these incorrectly. I think they should be called bow windows, they have gallows brackets underneath the lower sill.

We moved in to the house about 4 years ago, it had single glazed wooden windows in that were very rotten. So the first job was getting them replaced with upvc.
The fitter at the time had some problems with the structure being rotten and replaced some pieces (I think in the bottom part).

There are 2 posts in there, they're round and look to be aluminium (but could be steel).

I removed the plasterboard as there was some damage (sag) from when the windows were replaced and I could feel a draught coming through, the plaster board felt cold (I've just been patching up the ceiling in the same room after we had extra electric run in for a kitchen fit earlier this year and figured it was a good time to re-insulate, see if I could remedy some of the issues with the window. This one isn't too bad, the lounge one is twisted I think as one of the windows doesn't shut properly. I had the installers back a few times to remedy but in the end gave up and figured I'd fix it myself when I re-decorated the rooms.

I'm concerned about the gaps at the edges. I'll get more pictures in the morning.

When your referring to a lintel do you mean the one for the house main wall? If so that was the lintel the house was built with. You can see drywall adhesive stuck to it in the last picture.

There is no lintel over the posts on the window installation, as far as I can work out, the roof is just resting on the window units.

Not sure if I've clarified or confused things there.

I'm doing all the work myself, I'm practical but don't have knowledge in this field.

 

[80sman]

I shot of the house from the front before the windows were replaced.

IMG_0482

• 80sman
• 27 Nov 2018

 

[bobasd]

the day light at a mitre suggestion maybe wrong - its not a mitre and the "daylight" streak could be somethin else. an outside detail pic of fascia will show what it is if its anything.
i wasnttalking about the outside brackets under the sill.
the pic of your lintel is clearer now an i can see its probly a Catnic cavity wall lintel. remove the old adhesive an pack down from th lintel an fix a one piece of plasterboard when you come to board it up.

use search button for - "bay roof insulation" to get an idea for how to insulate your roof.

 

[80sman]

Thank you for the help Ian and Bob, I'll celotex it as Ian suggested.

Regarding the daylight, I've attached some pictures from the outside, I think it's just where trim meets up with the beam, I'll fill the gap with some brown silicon.

IMG_20181128_092033

• 80sman
• 28 Nov 2018

IMG_20181128_092021

• 80sman
• 28 Nov 2018