1930 Upstairs bay window cracks

[Tiptop28]

Hi, I'm in a 1930 semi with Canterbury spur render. Was starting to decorate front bedroom. Had a crack on bay corner so decided to chip away to fill in properly. In doing so in chasing out the cracks to fill I've found the chisel goes into a 4-6in depth gap. It varies in depth as you work up the wall. As you can see its wider at top than bottom. Small crack on opposite corner but nowhere near as bad.
Had new pvc windows put in 8 years ago, replacing aluminium ones.

I've seen the forum here discuss bay straps or have the bay underpinned. Hoping to call a builder tomorrow but wanted to hear other opinions.

Images show corner working way up as you go. I stopped chipping away as hole got bigger!!

Cheers

 

[blup]

It might be the result of the installation of the double glazing.

How long has the crack been there? Has it got bigger. Does it go through to the other side?

If not you could fill it and see if it gets worse.

As I understand it - as a DIYER - bays are not always properly tied in to the main structure of the house and comprise a frame of wood and brick infill, hence the void you have found.

You could see what your builder says and if it's serious consider a second opinion from a structural engineer.

Blup

 

[mrrusty]

I agree it may well be because of DG installation. I have seen a lot of very similar threads on forums. maybe not the case here, but it seems to me an awful lot of window companies don't realise that the window bay poles are often fully structural, take out a timber window and don't replace properly.

 

[catlad]

Outside pictures of the property will help.