Damp Bay Window

Smalltowngirl_95

Smalltowngirl_95

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Hi All - I'm looking for advice we've recently bought a house and we have got damp on the inside of the upstairs bedroom on the bay window reveal. Previously the windows were wooden framed but we have had them replaced to UPVC.

From looking inside we have noticed there doesn't seem to be insulation as we can see the wooden frame and what appears to be black felt.

Just wondered if it is due to cold air that we are getting the damp? The guttering has all been cleared and isn't leaking.

Any advice would be much appreciated.
 

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When they took out the old downstairs window, what did they add to support the bay above it?

Or is it just standing on PVC?
 
To be honest I haven't got a scooby doo as I wasn't there. I know behind the rendering it's a wooden frame
 
OP,
What did the mortgage surveyor have to say about any bay defects that were obvious at the time of the survey?
Given the large size of the defect below the window board, and the historical, repaired damage over the outside corner bead it might be worthwhile for you to open up the interior damp affected area - and post a pic of what you expose - and a larger context pic of the pic #2 whole area?

Are there any damp stains on the ground floor bay ceiling?
That a supporting ledger batten has been installed below the window board suggests that support for the window board was lacking - typically, a 2x framing top plate would provide support for the board & the Pvc window frame.
 
OP,
Presuming that you have suspended floors I also noticed that the lower cavity wall brickwork doesn't seem to have any air bricks - although its difficult to see clearly on your photo?
The Pvc frames FWIW appear to be level and plumb.
 
ree said:
OP,
What did the mortgage surveyor have to say about any bay defects that were obvious at the time of the survey?
Given the large size of the defect below the window board, and the historical, repaired damage over the outside corner bead it might be worthwhile for you to open up the interior damp affected area - and post a pic of what you expose - and a larger context pic of the pic #2 whole area?

Are there any damp stains on the ground floor bay ceiling?
That a supporting ledger batten has been installed below the window board suggests that support for the window board was lacking - typically, a 2x framing top plate would provide support for the board & the Pvc window frame.
Click to expand...
To be honest the surveyor didn't really mention anything about it, they just mentioned to get the rendering re-pointed where it joins the brickwork and to get he guttering cleared.

No there was no damp stains in the ground floor bay window ceiling or anywhere underneath. The window fitter did mention that the upstairs window cill wasn't the best as it was very tiny in depth.
 
ree said:
OP,
Presuming that you have suspended floors I also noticed that the lower cavity wall brickwork doesn't seem to have any air bricks - although its difficult to see clearly on your photo?
The Pvc frames FWIW appear to be level and plumb.
Click to expand...
I've checked and there is air bricks at the bottom of the bay as we do have suspended floors. We've already renovated downstairs

We've checked all the frames and they're all sealed and levelled correctly
 
JohnD said:
I think it's cracking and falling away as not properly supported, enabling rain to get in through the gaps.
Click to expand...
I asked the window company and they mentioned the Frameworks supporting the bay is wooden, as what was used in the 1930's when the house was built
 
Downsey_95 said:
I asked the window company and they mentioned the Frameworks supporting the bay is wooden, as what was used in the 1930's when the house was built
Click to expand...
It's possible that they are skipping over the fact that when the house was built, it had sturdy window frames made of thick wood, capable of supporting a bay, and now it hasn't.

I am not in the window trade but I believe supportive metal pillars are supposed to be used, concealed inside the plastic, when pvc is used in these situations.

It might be relevant that it costs extra....
 
Thank you John, I'll speak with the window firm and take it from there. Appreciate your advice
 
Bay single skin? Usual for 30’s , bays were often just a pile of bricks laid between timbers which move and crack render ( which has failed externally) , add to that poorly installed Uvpc windows and it leaks like a sieve.
With mine I removed external render , added wire mesh reinforcement and re-rendered. Internally added 25mm of Celotex , boarded and skimmed adding deeper window boards to hide the deeper walls .
 
foxhole said:
Bay single skin? Usual for 30’s , bays were often just a pile of bricks laid between timbers which move and crack render ( which has failed externally) , add to that poorly installed Uvpc windows and it leaks like a sieve.
With mine I removed external render , added wire mesh reinforcement and re-rendered. Internally added 25mm of Celotex , boarded and skimmed adding deeper window boards to hide the deeper wall
Click to expand...

Thank you for this advice it's a great help! Yes our bay window seems to be single skin. It looks like the render which joins onto our way forming the corner has come away and we can see straight outside. I think we're more concerned how it's all held up but it's probably used reinforced timber.

I think we will be removing the current render and have it redone, will consider adding the wire mesh if this helps support.

Did you leave a gap between the celotex and the reverse of the render for airflow? Our window cill is absolutely tiny so we're probably going to build a false wall in front to get the deeper cill.
 
JohnD said:
It's possible that they are skipping over the fact that when the house was built, it had sturdy window frames made of thick wood, capable of supporting a bay, and now it hasn't.

I am not in the window trade but I believe supportive metal pillars are supposed to be used, concealed inside the plastic, when pvc is used in these situations.

It might be relevant that it costs extra....
Click to expand...

Do you think it's worth asking the window firm? I'm guessing they will know it was load bearing when they fitted the new windows
 
I haven't had one quite like yours, but I've had them with a strong timber frame, tile-hung or pebbledashed on the outside and L&P on the inside.

Easily improved by cleaning out and adding membrane, insulation and plasterboard, with extra sockets on the bay and mineral wool in the floor to block draughts. I like to pack mineral wool into the frame as it is easy to fill tightly with no gaps, blocking draughts, but the foam is a better insulated. You can lay an extra sheet onto the face.

But in your case I think a new timber box frame is needed, and I would use sheathing ply on the outside for extra strength and rigidity, and new brackets off the wall. IMO the old frame is poor and falling off.

If you can find a leadworker, they can probably make it more weathertight than you could do yourself.

I don't think your window contractor is up to it.

When you expose the timber, there is a chance you will find it is well made and just needs woodworm killer, new brackets and screws

But I doubt it.
 
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