Big diagonal cracks by my window... eek!

JennyB

I've just recently noticed a very long diagonal crack running across my bathroom window. I say across the window but it is actually two diagonal cracks running away from opposite corners. It starts about a foot away from the bottom right hand corner of the window recess and heads up to the corner of the actual frame and is pretty much the same in the top left hand corner of the window. I'm not sure how long these cracks have been there but if they've been there long I'm surprised they weren't noticed before. I've lived in this house for a year, it's about 100 years old, not in a mining area. There is a rather large tree in our neighbour's garden which stands about 3 metres from the window in question. It's a pine tree and it's taller than our house.

You know what I'm thinking right? :eek: Is it the S word (subsidence) or is there some other more innocent explanation. I'm a little bit concerned...

polybear

Two questions:
1. Are the cracks visible inside and outside the house?
2. How wide (not how long) are the cracks?
Polybear

JennyB

Inside only - i think, though can't be sure (dark so can't check at the mo')
Narrow - certainly not as wide as the edge of a coin

roswell

can you tell how deap they are : eg are the bruicks cracked as well or just the plaster? also is there dirt / dust /cobwebs etc in them

polybear

If the cracks are internal only then don't get too worried at this stage. Also, they're not very wide either which is another good sign. My own house is prone to similar cracks (1920's, shallow foundations, large tree outside the front garden, clay soil). The cracks tend to appear in the summer (when the soil dries) and close up again when the wet weather starts. Some advice:
1. Don't panic and assume the worst.
2. Don't take too much notice of people who think they are experts.
3. Don't get onto the insurance company at this stage - no need in my (non-expert) opinion. The last thing you want is to raise the possibility of a subsidence stigma on your house if it's uneccessary, especially if you want to sell again in the not-too-distant-future.
4. Remember, subsidence claims (usually) carry a £1000 excess.
5. If things do start to get very serious then underpinning can get very complicated. For example, if it's a terraced house then it may be necessary to underpin the whole block. Otherwise your house will be nice and solid and the others will still move up and down with the seasons. Equals cracks. (A row of five terraced houses is actually one building with five front doors)
6. Houses move. Always will. Cracks, whilst often a pain cos' they spoil the wallpaper, are rarely structural.
7. Remember, once things are written down then you can't go back.
8. Start to be wary about swapping building insurance companies every year - can make things awkward if two companies start arguing about who is responsible for picking up the tab......
9. Be very,very wary about any idea of removing the tree. This can cause heave (basically the opposite of subsidence, i.e. the house goes up instead of down). In serious cases equals demolition.......
10. If the tree is very large (as in your case) then it's been there a long time so the tree/soil/house should hopefully be fairly balanced out. When a new tree starts getting large and changing the soil around/beneath an existing house then that is bad news.
11. People often blame trees. There are other causes, such as leaking pipes etc. I know of one case where a pipe had been leaking for a long time. When the owners realised and had it fixed it the resulting drying out of the soil caused such serious structural damage that the house had to be demolished.
12. Cracks from corners of windows (as in your case) are common - the corner creates a stress point that cracks just love to start from.

To summarise, please don't worry just yet. If you are really concerned then consider asking the opinion of a good reputable builder, or possibly a surveyor (ask an estate agent for a few names). Keep it low key though - personally I wouldn't advertise the fact to the neighbour's too much.....

p.s. I'm not in any way an expert, just been in a similar situation with a tree affecting the neighbour's house (mildly). The outcome? About £1800 to my neighbour for repairs (replacing damaged brickwork etc.) and the local council reducing the size of the tree GRADUALLY over several years.

Hope this helps.
Polybear.

JennyB

Thanks Polybear that's very helpful. Hopefully it's nothing to worry about by the sound of it. I think I will just continue to monitor things at the moment. It gives me a dilemma about the tree. We've been lobbying our neighbour to cut the tree down because it shades our garden so much and drops a lot of pine needle type things on the garden. The neighbour is also keen to cut it down so I imagine he may get onto it soon. So do I now reverse my position and start lobbying him to not cut it down! I say "it" but it is in fact two very large trees planted only about 2 feet apart... what were they thinking? And about 2 metres away from these trees they have a horse chestnut tree which is about 10 feet tall and growing... this is a terraced house with a smallish garden... hmmmm

Roswell - nothing inside the cracks as far as I can tell, they are really quite narrow. I've just checked outside and there don't appear to be any cracks in the brickwork. Hoping this is good news :-)

culpepper

When we came to view our house, my late FIL came too. We noticed a large crack on the stair well and he (architect and surveyor) said it was common in older houses and not to worry as it was only inside ,not out.

When they cut down trees, I suppose they leave the roots in the ground don't they? So there wouldn't suddenly be a hole under the house.

polybear

Jenny B said:
>It gives me a dilemma about the tree. We've been lobbying our neighbour to >cut the tree down because it shades our garden so much and drops a lot of >pine needle type things on the garden. The neighbour is also keen to cut it >down so I imagine he may get onto it soon. So do I now reverse my position >and start lobbying him to not cut it down!

Cutting the tree down would be VERY VERY bad news. Before even contemplating such a move I would recommend seeking the advice of a (a) good structural engineer (one who understands trees); (b) an Arborculturalist (tree surgeon with qualifications); (c) the local council buildings control dept. and tree officer. At the very least I would expect that they would take the precaution of reducing the size of the tree over a number of years. They may say leave it alone completely; they may say that after reducing the size of the tree then leave it alone, or they could agree to it's removal. It'd be a long term project though, so don't expect things to happen overnight. Your neighbour won't be happy though, because it'd mean multiple visits from the tree surgeons, rather than doing the job in one go. Long term though - he'll be glad he did do it that way....

>Roswell - nothing inside the cracks as far as I can tell, they are really quite >narrow. I've just checked outside and there don't appear to be any cracks in >the brickwork. Hoping this is good news :-)

This is very good news.

Culpepper said:
>When they cut down trees, I suppose they leave the roots in the ground >don't they? So there wouldn't suddenly be a hole under the house.

Two problems then arise:
1. The water that was being taken up by the tree now remains in the soil - this can cause the ground to swell, which in extreme cases can cause heave (very bad news).
2. The roots in the ground gradually die off and rot away, leaving voids (holes) in the soil. Soil settles. Anything above settles too....

Any ideas about what type of soil your house is on? London Clay, for example, is notorious for swelling & contracting due to moisture content. That's what's under my house...
For anyone else interested in this this subject, the type of tree makes a big difference also. Some for example, can even detect water inside underground pipes and will actively seek out the pipes and break them. Tree roots can extend over a large area also (from memory some go 3 times the distance of the tree's height).

When I was battling my local council to stop them removing the tree outside our house (their tree) - I kept parking my car underneath every time they came to cut it down - they said they had to because my neighbour was suing them (he didn't want the tree down either, he only wanted his house fixed). I asked that if the council had to cut it down then please do it over a number of years, to reduce the risk of heave. The council refused - they said that (if I were to get heave) they'd worry about it if & when it happened!! Then my neighbour died, so the threat of court action disappeared. Suddenly all the council experts said that it was better to reduce the size of the tree over a number of years then maintain it at that size. I'd been telling them that all along.........

Polybear