survey found signs of subsidence - need advice

mmoalem

Hi there all - a survey (home buyer report) on a house we are planning to purchase in london have come up with the following (the house is a typical 1930s end of terrace, 2up 2down affair with small extension on the back):

The main wall fabric to the main building, in particular the two-storey front bay and single storey extension, have, in our opinion, been affected by past structural subsidence emanating from foundation level.

This movement emanates from the building's location upon a clay sub-soil, which is susceptible to shrinkage during periods of prolonged dry weather, a factor marginally aggravated by a replacement immature tree with the front pavement.

It is clear that the main movement occurd during the building's early history; similar movements including modern fracturing being noted to the neighbouring properties in the terrace, in particular to front bays.

There are however, hairline internal plaster cracks to the right-hand side of the front bay at ground level; hairline plaster cracks above the side window and rear external door in the kitchen extension, together with a hairline external crack to the front bay at ground floor level projecting through a modern decorative finish, together with pulled joints at first floor level between the front bay and main elevation.

It is likely that modern internal plastering and external redecoration has been completed to the front bay to conceal past movements.

There is, therefore, a risk of further subsidence which could require expensive and extensive foundation repair, i.e. underpinning.

notwithstanding the above, the degree of movement, as indicated by the modern cracks, is slight and in our opinion further subsidence of any consequence is unlikely to the main building during normal climitic conditions.

under 'Risks:' he adds

The adverse site conditions should be reflected within the building insurance cover, i.e. a fire insurance policy which incorporates a valid 'subsidence, landslip and/or heave' clause.

In view of the building structural history, it would be prudent to continue with the building's existing insurers, these insurers confirming in writing that they are aware of the building's structural history.

to my untrained eyes this looks very scary and reading about it a bit on the web seems like it could be very difficult to insure the property. on the otherhand i was told i am unlikely to find a property in the area not effected by subsidence and that the surveyor just want to cover his a**

what do you think? a complete no-no or just an average property?

the vendor said she changed insurer recently and they sent someone to look at the house and than said there was no problem insuring it.

talking to the surveyor directly he put it like this - on a scale of 1 to 10 an average property risk will be 5 and this one is 6.

talking to one insurer (swinton) on the phone they said they would not provide a quote to a house which suffered subsidence damage unless repairs been done to the damage. (in his report to the bank the surveyor mentioned he could not see evidence of work done on the property as a result of movement caused by subsidence - not even sure what this exactly means)

not sure how to tackle this - should i get a builder or structural engineer to advise on repairing the damage (from the above i dont even know what is the damage!)

Yorkie1

Who told you you're unlikely to find a property in the area unaffected by subsidence? Do they have an interest in you buying this house or are they truly independent and well-informed?

The insurance is always a difficult one. Some insurers will automatically decline, some will load the premium / excess, others will not be bothered once they know they full history and have checked its current condition. Don't necessarily believe what the seller tells you, they may be legit but then they have a house to sell...

When I was buying my current house I previously looked at one which had had underpinning quite a few years ago. Everyone told me to avoid with a bargepole on the grounds that other houses would come up without this added complication. They were right.

That being said, I am no expert on building structure so do wait for someone else to come along who does!

mmoalem

various people said subsidence is a common problem in london. The surveyor himself said he would expect to find signs of subsidence in this type of property in the area but he said he would not necessarily expect to find the hairline cracks he seen also he could not rule this out.

Yorkie1

A friend of the family lives in the Dulwich area of London and is on their second of third lot of underpinning in as many decades caused, I think, by clay shrinkage type of issues.

London is a very big place and I'm sure there are plenty of parts of it which don't suffer subsidence.

warez22

I am just in the process of having my house 'underpinned' - it is going to have 38 piles 10m deep to stabilise the property.

I have been told that once it has been done, it wont need to be done again.

I, too, am on clay soil and that it the reason for the subsidence.

The value of my property wont be affected, just the amount of people willing to buy it.

I will need to continue with my existing Insurers forever, so they can do what they like with the premium.

With hindsight, would I have bought the property?.......probably not.

mmoalem

thank you all for the replies but i think i need to clarify something.
now that i read about it i am aware of the hell awaits a house that requires underpinning. the issue is that i cant dont get the jargon of the surveyor in one paragraph he warns of the need of underpinning and in the next he said that this unlikely to occur.
what i need is someone to decipher the jargon...
i have seen a soil map of london and pretty much all north london is on clay. as far as i understand subsidence is a risk for any house built on this clay and many houses suffered some kind of movement in their history. He did note in the survey report that underpinning is not required as it stands.
i am aware that he has to cover himself against any future issues but i need to try read between the lines of the report to know the risk involved in buying the property and i have no knowledge to help me with that - maybe someone here can actually comment on what the survey says...