Subsidence in SE22

[jomchugh]

Hi, I have recently bought a flat in East Dulwich and discovered that it is expensive to insure against subsidence because parts of the SE22 area are at risk of subsidence. Has anyone else had this experience with insurers? Have you heard the area is a high risk area and what does this mean? What is the story about the clay in the SE22 area? Jo

[elderflower]

Dulwich from sydenham to peckham has random subsidence problems. No one likes to talk about it because of what it does to house prices and possibly because those affected only find down the line when they want to sell up.

The 20th century built properties seem to be the worst affected. If the insurers are being picky then maybe someone in your immediate area has had problems with it.

Good luck

[Mark]

These might help http://www.eastdulwichforum.co.uk/forum/search.php?5,search=Subsidence,page=1,match_type=ALL,match_dates=365,match_forum=ALL

(except the one about pelvic floor exercises)

[mikese22]

Your main problem will be if your homebuyers survey finds evidence of subsidence - if no evidence you shouldn't have any problem

I insure with lloyds T S B and no issue - despite a few dodgy cracks and floors you could roll a tennis ball down!

[SteveT]

A-plan. Scott Feltham. (01420 593493) This was provided some months ago by Marmora Man who has had similar problems with his se22 postcode.

[seanmlow]

I have heard of issues with subsidence in roads around Landcroft (Thompson, Goodrich).

[Chener Books]

Two pointers to help avoid these problems:

[1] Check the British Geological Survey map for East Dulwich. Identify the marked clay-slumps, and follow the topography to identify the line of potential future clay-slumps.

[2] Check a mid-19th century Ordnance Survey map and identify the brick-fields.

If you pay for a survey make sure the surveyor addresses these points.

Our local estate agents are the experts and will advise you which properties not to buy.

John K

[peterstorm1985]

When you are ringing up for insurance quotes be aware that some insurers zone risk areas by individual street and some by postcode. This is why you can get a huge range on quotes (and some blank refusals) for the same house. If there is no known subsidence in your street it is worth ringing around to find an insurer that considers risk on an individual street basis.

[HennyPenny]

Is John K really expecting a prefessional estate agent to advise a buyer not to buy a property? Agents act for a vendor, and if that were the case very few houses in the area would be sold, and your property values (re other postings) would fall dramatically. One has to look at every situation. Not all movement is subsidence - a lot of this is over zealousnous (real word?) by panel mortgage surveyors (who don't always know the area) looking to cover themselves against any litigation and hype by buyers looking to get a price reduction. One very wise surveyor told me years ago that houses are like old grannies; they sit themselves in a chair, wriggle about for a bit and then get comfy. The same with houses - the soil/clay is seriously distubed, a heavy weight put on the site, and this then finds its own comfy position - a lot of 'movement' is historic. I am not saying there aren't cases of subsidence, but one needs to instruct a reputable local surveyor who understands the geological structure and look at the positioning of trees etc. We love Dulwich because it is a green and lovely area - and trees (which drink huge amounts of water every day)do cause problems -if you do have this problem, talk to Southwark. An established agent with years of experience will understand issues with certain roads and advise accordingly - for example, one road in the area has 2 issues - the length of the party wall is so long that the houses 'pull apart' in the middle and the front bay windows had a green oak lintle installed - over the years this has dried out and bowed a little causing the bricks to sag - these houses are not falling down.

If you are having issues with buildings insurance, which you need to have on the day of exchange, agree with the current owners insurance company to continue to insure the building they can't say no. This is something that your solicitor will advise on.

HP

[Penguin68]

If you are buying, and you believe there may be a problem (or you are being told there is one) your seller may be able to provide you with the original survey done for him/ her - if that identifies 'problems' (for instance wall-cracks) which are essentially unchanged since then (assuming the survey was done some time ago) this may help identify a 'problem' which (see above) has stabilised. Also check to see if trees have been recently removed close to the property, as this will alter the local water table without necessarily being a substantial or real problem. I have said on another thread that (in the expectation that you will eventually want to sell) recording the state of a property when you buy may prove helpful later when selling - my house has a hairline crack in it unchanged over 20 years since I bought the house, and associated probably with a later (pre-war) built garage but which could still trigger concern in a casual surveyor, charged (unless you are instructing him/ her) with protecting the mortgagers interests.

Many structural experts are now much less worried about subsidence, particularly in older houses which have had time to flex, than they were previously - collapse is far less common than one might think, and the symptoms are normally pretty dramatic and visible long before the walls go down. That doesn't stop (some) insurers being ultra-cautious of course - mainly because builders who address subsidence do so whole-heartedly and expensively.

[cate]

Chener Books Wrote:

-------------------------------------------------------

> Two pointers to help avoid these problems:

>

> [1] Check the British Geological Survey map for

> East Dulwich. Identify the marked clay-slumps, and

> follow the topography to identify the line of

> potential future clay-slumps.

>

> [2] Check a mid-19th century Ordnance Survey map

> and identify the brick-fields.

>

> If you pay for a survey make sure the surveyor

> addresses these points.

>

> Our local estate agents are the experts and will

> advise you which properties not to buy.

>

> John K

What is a brick field?

I don't think saying local estate agents are experts is correct. Why would you say that?

[Gimme]

South London is given to subsidence. That shouldn't stop insurers insuring you.

For example, Churchill ask the question "Are you aware of any subsidence in your local area" and when you check what this means they say "within 100 metres". So unless someone in your street has had subsidence, it shouldn't be an issue.

Some insurers make the 'local area' very vague but if it meant the whole of ED or the whole of S London there would be a lot of us with no insurance.

[Penguin68]

What is a brick field?

A brick field is a site from which clay has been 'mined' to make bricks - if the site has been fully depleted of clay, houses built over it are less likely to subside, as they are not being built on an existing clay substrate - however if the brick field is not exhausted then there will still be clay residue on which houses may have been built. Unless you can be sure that the site is exhausted then it indicates just that there is, or has been, underlying clay. Normally brick field sites will have been depleted of (most) clay, I believe, as that would have been the economic action before selling the land and acquiring a new site for clay 'mining'.

[SteveT]

Chener books wrote:- Our local estate agents are the experts and will advise you which properties not to buy.

It would be more accurate to say they could advise you, the facts are they may indeed know which ones to recommend but when their commission is at stake they will tell you anything to suit them and their percentage.

[Chener Books]

Brickmaking was the major East Dulwich industry in the 19th century. Firstly supplying bricks for urbanisation north of East Dulwich and latterly for East Dulwich itself. The last brick field seems to have closed before 1880.

It is likely that some of the smaller brick fields are not shown on maps because they completed their production cycles between map revisions.

The brick fields were on the lands of Friern Farm. This was roughly the area bounded by East Dulwich Road, Peckham Rye (road)/Forest Hill Road, Wood Vale, and Lordship Lane. I assume they were let out on leases.

The London Clay was 'mined' by digging clay-pits. As they were on undeveloped agricultural land it is likely they expanded sideways rather than downward.

The layer of London Clay under East Dulwich is quite thick. If they were 'mined' to to near exhaustion we would expect to still see the remains of clay pits 100 feet or more deep. If they were 'mined' to exhaustion, that is down to the chalk aquifer, we would now have a number of old clay pit deep ponds.

Shallow clay pits are likely to have been backfilled before housebuilding.

With the boom in housebuilding over the massive demand for bricks faded away. The benefit of profit dervived from decreasing demand was eventually trumped by the increase in land values. At some tipping point the owner of Friern Farm decided to sell the farm lands to the British Land Company which sold on small building plots for individual terrace houses at ?4 a plot.

It is interesting to note where the Victorians did NOT build houses.

John K

[nunhead_man]

Interesting Chener Books - I've learned something

Most places I see are OK until disturbed in some way - some mentioned in those links given above - for example;

* underpinning an one property in a terrace/pair with a concrete float so creating movement with the other/s - no longer done very often!

* planting new, especially non-native trees too close or allowing treesto grow too large - tree roots typically same spread horizontally as tree is high

* some change in water flow - e.g. paving over a previously garden with earth open to the sky so drying out clay or a long term leaking drain or pipe - clay ?heaves? (swells ) both as it dries and as it gets wetter

Seems to me living in a Victorian house is a bit like driving an old car - one needs to know it?s foibles

[sophiesofa]

> * planting new, especially non-native trees too

> close or allowing treesto grow too large - tree

> roots typically same spread horizontally as tree

> is high

Doh, I always thought the roots only spread as far as the fattest bit of the tree. I think I need to fell the 20 ft fir tree that's less than 2 metres away from my flat asap!

[Penguin68]

Some trees have roots which spread and are close to the surface, birch I think are like this, some which go down quite far before spreading - conifers I think have deep roots - but you should check. Deep-rooted trees are less likely to have an impact on buildings (re roots coming into drains etc.)- but will of course take-up water.

If your house is stable removing a tree close by may actually make things bad, by allowing the water table to rise now nothing's drinking it.

Take advice, would be my advice, from someone who knows the impact of different sorts of tree.

[sophiesofa]

Thanks Penguin I shall seek advice. I won't get my rusty yet trusty saw out tonight then!

[Chener Books]

Here are scans of two small engravings published in 1841.

They show the Ladlands northern and southern slumps.

The Victorians did not build here.

John K