Bay window problems...advice needed.... :(

[David5247]

Hi,
The bay window in the main bedroom of my house has been cracking, the crack goes from the bottom of the window down to the skirting board. Within a few months the cracks have become bigger, I paid for a structural report, in the report it said that the bottom bay window double glazing was not strong enough to support the above bay window which was causing the cracking. We then paid for a stronger reinforced double glazing hoping that this would solve the problem but it did not. I removed the plaster around the cracking to reveal the brick work ect underneath and to my shock you can see sun light through the cracks, the cracks go from the inside to the outside and do not appear to be stopping, it seems to have slowed down after the reinforced glazing was installed but not stoped. The bottom bay window seems to show no signs of cracking ect. I read on the web that the slabs which support the bay can sink and move ect causing this?? am unsure of what to do next to resolve this and so far attempts have cost alot of money and have not sorted the problem?????

left side bay Jan 2012

• David5247
• 27 Jun 2012
• 1

left side bay June 2012

• David5247
• 27 Jun 2012
• 1

left side bay June 2012

• David5247
• 27 Jun 2012
• 1

left side bay June 2012 close up

• David5247
• 27 Jun 2012
• 1

right side bay june 2012

• David5247
• 27 Jun 2012
• 1

view of bay june 2012

• David5247
• 27 Jun 2012
• 1

Rear pic

• David5247
• 27 Jun 2012
• 1

rear pic 2

• David5247
• 27 Jun 2012
• 1

front bay pic

• David5247
• 27 Jun 2012
• 1

front bay pic 2

• David5247
• 27 Jun 2012
• 1

front bay pic 3

• David5247
• 27 Jun 2012
• 1

front bay pic 4

• David5247
• 27 Jun 2012
• 1

front bay pic 5

• David5247
• 27 Jun 2012
• 1

front bay pic 6

• David5247
• 27 Jun 2012
• 1

Updated pics as requested, sorry for the poor quality, used phone camera.

 

[catlad]

A few more pictures showing your whole house from the outside and a few more of the bay from outside, plus the roof line will help.

 

[David5247]

updated pictures.

 

[David5247]

thank you, yes looks much better.

 

[tony1851]

This is a common problem when uPVC replacement windows are put in bay windows of older houses.
The wall between the top of the lower window and the cill of the bedroom window is usually lightly-built, often with single-skin brickwork, perhaps reinforced with a few timber uprights, rendered inside and out.
As originally built, this wall would have rested directly on the window frame.
The original window would have been timber, with 4 or 5 substantial uprights, which would have been adequate to support the wall, All you have now is a thin PVC member, which will not be sufficient to support the load without excessive deflection. In some houses, the floor beams of the bay also rest on the frame.
In many instances, the movement eventually stops, but it can eventually affect the seal of the double glazing.
There is no easy solution to this problem as much depends on the original method of construction which can only be ascertained by a careful survey.
I wouuld suggest this is beyond a DIY job, and in this instance, you really need to get an SE to give it some thought and come up wih a suitable repair scheme. The report you have already had just states the obvious.

 

[stuart45]

I would guess that the structure above the lower bay is probably timber framework, which is quite common when it's been rendered. It may be possible to fix the studwork back to the brickwork with a better fixing as well as using bay poles below.

 

[catlad]

Not a lot to add to that plastic is not as strong or as stable as wood.

 

[tony1851]

I would guess that the structure above the lower bay is probably timber framework,.

Stuart, if you magnify his 3rd and 4th image down (the ones with the missing plaster) it looks very much like a brick-on-edge wall behind, and I doubt just fixing the side studs to the main wall will restrain it.
Yes, ideally he needs corner poles, but those by themselves won't take the bend out of the pvc at the top of the frame.
I had to design a repair for a similar situation recently, and had to re-build the brickwork above, on top of a steel angle fixed to plates on corner poles. The aim was to keep the weight of the wall (and of course the bedroom window) off the lower frame.
Personally I feel the OP needs to do something comprehensive with this,
even if it means re-building from frame up. A makeshift repair will probably be spotted on a survey if he sells.

 

[stuart45]

The brickwork looks like the main house to me with studwork to the side, which is more common over a bay when rendered or tile hung.
Can't be 100% from a photo though and the wall needs to be exposed more to identify the problem better.

 

[David5247]

Thanks for the advice guys. Why would the original SE survey recommend replacing the old bottom PVC window (which replaced the wooden ones about 3 years ago) with a reinforced PVC window if is would not resolve the issue? (These windows have adjustable steel poles either corner that the previous PVC window did not for extra support which by the sound of things is not enough) Would the SE not of seen this without removing the plaster?

 

[stuart45]

Have read of this.
http://www.expertexpert.com/bays.htm
BTW, is that timber or brickwork above the bay?

 

[David5247]

The bay is made of timber uprights with brick in between, from what I can tell after removing some more plaster.

 

[stuart45]

The brickwork is an infill and the timber frame is the main structure.

 

[tony1851]

David, if you read the link given by Stuart, you will see that it may not be a simple DIY job.
The link advises a steel angle sopported off tubular corner posts, to take the load of the brickwork off the plastic frame.
You will notice that the bricks in your bedroom bay are laid on edge rather than flat. This was done to save weight but because it is not a particularly secure way of building, they would reinforce the brickwork with pieces of timber.

 

[tony1851]

Why would the original SE survey recommend replacing the old bottom PVC window (which replaced the wooden ones about 3 years ago) with a reinforced PVC window if is would not resolve the issue?

Answer: because he does not know his job.