Is this subsidence? Photos included. Please help

[BloodyStupidHouse]

I live in an extended 3 bed end terrace. 8 years ago I had my kitchen extended and it was a big job.

All signed off and no issues at all until about a month or so ago, maybe a little longer.

I noticed cracks inside above the door. Looking outside, there are 'stair stepping' cracks in the pointing, again above the door.

My worktop has dropped at one end. My door appears to have dropped - it won't shut properly

There is also what appears to be a distinct dip in my lawn - directly outside the extension on the corner.

My neighbour has some very tall trees in his garden right next to mine. They're well over house height and about 17 feet to the side of the extension. These weren't deemed an issue when the build went ahead

My buildings insurance company said it isn't subsidence and they've got no suggestions for me. They are basing this on a telephone call where they asked me 3 questions

I have had the original builder back out. He is puzzled and doesn't know what it could be - there have been no issues until the past few months

Any suggestions for me please? Do I need a chartered surveyor? Is this really not an insurance issue?

Washing machines leave particularly white marks on brickwork due to soap in the waste water. Might be relevant. It should run to a foul drain (not a rainwater soakaway) but might be escaping.

Close up photos of the bricks near the white mark. The black line of the DPC should be visible in the mortar bed about two bricks above ground level.

Sniff them for smells of damp or drains or Persil.

@PigletJohn thanks. Here's a close up. I can see black plastic too through the brick

I believed the white to be water deposits from where I water the garden (before the water ban!)

Another pic

Do you know if the trees were taken into consideration when establishing the depth of your foundations?

Species
Distance from Building
English Oak Black Poplar
Weeping Willow
Hawthorn
Cypress Leylandii Cedar
Douglas Fir Pine Spruce
Horse Chestnut
Ash
Lime Sycamore Pear
Orchard Cherry
Alder Maple Beech Plum Laurel Apple Silver Birch
1m 2m
**
**
**
**
**
1.80 1.70 1.70 1.50 1.70 1.50 1.60 1.40
1.80 1.70
1.80 1.70 1.80 1.70 1.80 1.70 1.70 1.50
1.70 1.50
4m 6m

• 2.30 **
• 2.20 2.10 1.80 2.10 1.80 1.50 1.30 1.20 0.90 1.20 0.90 1.10 0.90 1.50 1.40 8m 10m 2.15 1.95 2.30 2.20 2.00 1.80 12m 14m 16m 1.70 1.60 1.40 2.10 1.90 1.80 18m 20m 22m 24m 1.20 1.10 0.90 1.70 1.60 1.50 1.40 1.60 1.30 1.10 0.90 1.50 1.20 0.90 1.40 1.20 0.90 1.20 1.10 0.90 1.30 1.10 0.90 1.00 0.90 1.00 0.90 1.00 0.90 1.60 1.40 1.50 1.40 1.50 1.40 1.30 1.10 0.90 1.30 1.20 1.30 1.10 1.30 1.10 1.30 1.10 0.90 1.70 1.60 1.70 1.60 1.70 1.60 1.60 1.50 1.60 1.50 1.60 1.50 1.20 1.10 0.90 1.50 1.30 1.50 1.30 1.50 1.40 1.20 0.90 1.20 0.90 1.20 0.90 1.20 1.00 0.90 1.20 1.00 0.90 1.20 1.10 0.90 Foundation Depth in Metres

Sorry that didn't copy well.

Can you recall what the depth of foundations were and whether the trees had any bearing on whether the foundations had to go deeper?

Presumably the trees 8 years ago were not as tall but have to be taken into consideration that they obviously will grow.

nhbc-standards.co.uk/4-foundations/4-2-building-near-trees/4-2-4-the-effects-of-trees-on-shrinkable-soils/

https://www.oadby-wigston.gov.uk/files/documents/buildingnearrtreesleaflet/Building%20Near%20Trees%20Leaflet.pdf

Hi OP, use this site to find out your soil type www.landis.org.uk/soilscapes/

It's a leak FFS.

Forget the trees and the soil.

Your pic is not very clear but I think the efflorescence is (mostly) below the DPC, which is to be expected.

Get onto your insurance company immediately. If subsidence is happening and it's left too long they can deny the claim.

You can see it’s a leak clearly in this pic. The white line appearing is startling.

Het some chalk and mark the wall it’ll shoe if it’s still damp

Enquire with the coal authority they have a databse of old subsidance claims within 10 properties of your boundaries

We're on clay soil and every single time we have a really hot and dry spell in the summer, we get cracks in our extension wall. We've had the foundations checked, they're sound. We have been told it's the clay soil.

OP here! Just an update for anyone remotely interested. Thanks again for all your help.

It is indeed subsidence and it has been caused by the trees. There is no water leak anywhere and the drains are fine so that's been fully ruled out

Insurance company now dealing with thank god

Sounds like the MN resident “experts” got this wrong then.

Sorry to hear it's subsidence - that was a quick diagnosis.

Are your insurers going to pick up on the claim and will they claim against the tree owners?

@Synny I don't know as it's very early stages in the claim. I'm just thankful they've accepted it as it was looking like they would do at first. I'll pop back and update when things have moved along more

But yes, insurance company have accepted the claim, to answer your question. £1000 excess though which seems huge to me

@Technophobic umm yes. Categorically no leaks anywhere

Where does that down pipe go? It should run to a soak away. Have the builders just left it soaking away right next to the house? Check that first as it looks an obvious culprit.

@chocolateorangeinhaler see update

Yes, unfortunately most policies have a £1k excess in respect of subsidence.

I hope the tree owners take some urgent mitigation (tree removal) to prevent the damage becoming any worse and to protect you in the future once repairs are completed.

We had a small tree removed it was about 4 foot in higher at that point and it destroyed the porch. The roots shrink and leave the concrete on uneven soil.
a large tree has been removed from our small garden and this is now causing damage to the patio.
People don’t think about this when planting such trees.

When we sold the house we put tree root damage rather than subsidence on the sale form as it was only one corner.

Thank you, that's interesting.

Could you take photos as the work progresses and post on here please? I'd be grateful to understand it better.

How did the surveyor diagnose it?

@PigletJohn yes I will do that. So far, we've had a team of three out who checked all the drains and for leaks - they told me that my drains were the cleanest they had ever seen so that was a nice compliment

And then yesterday, an engineer arrived (sure it was an engineer?) and has so far completed a visual inspection and is coming back next week. He has done an initial report and said that in his opinion it is subsidence caused by the neighbours trees so now .. I wait and see what the next steps are

As my neighbour didn't want to lop his trees at all, this isn't going to be an easy solution

I'll update again in due course for anyone interested. Thanks!