Bay Window Subsidence

figgyroo

When I bought my 1930s house I was made aware that the bay window had been underpinned several years earlier. When my builders were installing the new windows they dug down and told me that the bay had not been underpinned, so they said they had poured concrete in to support it. The floors into the bay were really out so they jacked these up as much as possible. All cracks were made good, new sills fitted and everything redecorated.

This was about 5 years ago; cracks have now started to appear around the bay for example there are cracks between the windowsill and the wall as though the sill is moving away from the wall. There are also cracks down the side of the windows where they meet the wall and also cracks in the sill itself (it is a curved bay so the sills are made up of several separate pieces of wood). All crack as fairly narrow.

My question is, is this normal settlement or should I be worried i.e. does it suggest the bay window is subsiding again?

Any advice greatfully received as I am clueless about this sort of thing. Thanks.

ormus

you need to measure the cracks and keep an eye on them.
ie,
can you fit a small coin inside the cracks yet?

figgyroo

ormus wrote: »

you need to measure the cracks and keep an eye on them.
ie,
can you fit a small coin inside the cracks yet?

The largest cracks are those at the edge of the windowsill where it meets the wall. I can fit a 50p piece in these. The other cracks aren't large enough to fit any coin in.

leveller2911

Hi OP can you post some photo's as that would help ?.....

Just to add with bay window sills especially curved segemneted sills the joints will always shrink and expand during the coarse of the year. When we make bay windows we bolt the sills together with Kitchen worktop bolts and glue and they still crack. Its due to the fact that the sills are made up of several segments each moving at differnt rates..

Post some pics if you can........

ormus

the masonry cracks are the dangerous ones. keep an eye on those.
dont take too much notice of any cracks between wood and masonry. they expand and contract at different rates. thats normal.

figgyroo

http://photobucket.com/windowsandskirting

Never uploaded pics before so hope this works....

I've taken pics of the upstairs window and skirting board. Also there is a pic of the downstairs window. I hope you can also see the gritty sandy stuff which seems to accumulate there from somewhere above I presume. I only wiped them down yesterday and there is loads there again which I presume is not normal.

ormus

they appear to be normal settlement/expansion cracks.
the whole house moves a few mm over the seasons. hence the cracks between differing materials.

figgyroo

ormus wrote: »

they appear to be normal settlement/expansion cracks.
the whole house moves a few mm over the seasons. hence the cracks between differing materials.

thanks, that puts my mind at rest a bit.

leveller2911

Nothing to worry about they are just expansion/contraction cracks. If you scrape out all of the loose plaster,silicone sealant. Then use some decorators caulking in the cracks,allow to dry fully and then paint. The caulking will help stop cracking and you can paint over it.Don't use silicone on the inside as you can't paint over it...

Caulking you can buy at most diy stores and you will need a silicone gun to apply it with..

PS thought you had timber windows.........:D Pictures speak a thousand words.

figgyroo

leveller2911 wrote: »

Nothing to worry about they are just expansion/contraction cracks. If you scrape out all of the loose plaster,silicone sealant. Then use some decorators caulking in the cracks,allow to dry fully and then paint. The caulking will help stop cracking and you can paint over it.Don't use silicone on the inside as you can't paint over it...

Caulking you can buy at most diy stores and you will need a silicone gun to apply it with..

PS thought you had timber windows.........:D

Thanks, I'll do that. I did have timber windows when I moved in, the original ones...they were completely rotten! Not a fan of upvc but new timber ones were out of my budget.

ormus

yes i noticed that. you have three different materials there.
plaster, plastic and wood. all moving at varying rates.