Opinions please.

[treequip]

I was told that heave would only happen if the tree was there before the house! is this right?

 

Pretty much yes

[Lee Winger]

If a tree is causing subsidence a building can subside during the summer as the soil beneath its foundations dries out, and it will rise during the winter as the soil completely rehydrates. This is broadly what does in fact happen, except that the constant movement of foundations causes a gradual long-term settlement (sometimes referred to as "dynamic settlement"). Many buildings - particularly those of a more traditional construction - will tolerate considerable movement, so that there may be no harm done (or some that can be tolerated) But excessive movement of foundations can lead to serious harm to the building above. (C. Mynors)

 

 

 

Good question

 

What about the large visible cracks left the summer dessication/soil drying out?

 

Modern buildings ie house's built in the last 20 years are the only house built to with stand potential tree caused subsidence, all it means is the footing have been excavated deeper..........

[Jellystock]

That oak looks like its been pruned before, and I like others doubt it is having any affect whatsoever on the foundations next door. The connies are a bigger issue, but the biggest issue is the shoddy extension work, but its just so much easier to persue the tree than go back to a biulder who may have followed the rules and done the foundations to spec, but we all know these extensions are never as good as the old build.

 

Id go back to the nieghbours and ask them for a copy of the report and contact details of the surveyor, and start with an inquirey to him over the phone.

 

From these photos alone there is no evidence of any extension.

Houses are quite often built from new with various elevational and storey differences. Just because it looks like a box with additions it may have been built like that.

 

And on that note, theres nothing to suggest that the clients house has NOT been extended.

 

Oh, Tim Craig, Its Jellystock! I might not have a six pack but I also have no Jellybelly either!!

 

Jellystock.

[Lee Winger]

Pretty much yes

 

 

Incorrect, heave can happen any time, its only soil re-hydration around the footings........

[Lee Winger]

From these photos alone there is no evidence of any extension.

Houses are quite often built from new with various elevational and storey differences. Just because it looks like a box with additions it may have been built like that.

 

Wouldn't make any difference, building regs would stipulate footings to accommodate the subsidence potential...........

 

As I have already said investigation pits and plasticity test, is the only way to be certain, those conifers would be first on my list of culprits........

Edited January 16, 2010 by Lee Winger

[Lee Winger]

Branching out this summer? NHBC offers advice to homeowners

[treequip]

Incorrect, heave can happen any time, its only soil re-hydration around the footings........

 

It can’t happen anytime, it requires a shrinkable, desiccation and re whetting.

 

That circumstance isn’t universal therefore it can’t happen any time.

[Lee Winger]

 

That circumstance isn’t universal therefore it can’t happen any time.

 

looks like we are both loosing something in our posts, agreed shrinkable soils are a must............

 

Arborist wrote this ''I was told that heave would only happen if the tree was there before the house! is this right?'' you said pretty much yes.............which imo is incorrect

Edited January 16, 2010 by Lee Winger

[Mesterh]

I would say that the oak wont be causing the prob 0(if any), and like others have said it would be the conifers if anything, they would be drawing more water than the oak since they are sweating all year.

 

As Lee says though unless a soil/root sample has been taken then the tree cant really be brought into the equation.

[treequip]

I said pretty much because it’s way too broad a subject and would derail the thread.

In a nutshell it needs to be a shrinkable soil with a serious amount of desiccation (depending on how shrinkable the soil), caused and maintained by vegetation. Once the vegetation is removed the soil will re hydrate and expand as it does so. If your structure is sat on this soil you will probably have a problem.

 

Thankfully this is a pretty rare situation.

 

As you said modern building regs are a bit more up to speed but only if the inspector is clued up. Some aren’t!

 

Andy