Daft question about suspected subsidence and who to call

orangecrush

Update: called insurance. Bad news: they think it’s subsidence. Good news: it’s minor. Baffling news: they won’t help because they can’t see the full damage from Google street view. 

Hi moneysavers,

I don’t know why I don’t know this. But if you suspect subsidence, do you call a structural engineer first, then your insurer depending on the results of an inspection? (Cost £540) or do you call your insurance company? (Excess £1000). I can’t figure out from my policy wording whether the excess is for the works if required, or just if you suspect subsidence.

Fairly dodgy looking crack has appeared below our bay window, the paving has sagged there and some steps nearby are cracking. We have heavy clay soil and in a drought area so my heart has sunk. 

Any shared experience would be welcome! 

Alderbank

I would not trouble your insurers at this stage, but it sounds like time to get a professional opinion.

You mention drought. Are there any large trees near the front of your house? Is it an ex-coal mining area?

orangecrush

There’s an ash tree and a laburnum within 5 metres, and a lot of large shrubs within 1.5metres (previous owners were a bit devil may care with their plant sizes). 

Not a mining area thankfully. I’ll get a structural engineer out - I just didn’t want to pay the £540 for an inspection if the insurance company was going to do their own inspection as part of the process. 

Doozergirl

Your insurers will do an inspection as part of the process. 

If I wasn't sure, I'd get my own SE in first so I didn't make an unnecessary claim, but it does sound like there is definitely something going on. 

orangecrush

I think it’s pretty dodgy looking… but I’m going on google images on subsidence and comparing it to ours.

Some photos here… and a wee video. Hope this works… https://flic.kr/s/aHBqjA5i9v

stuart45

Ash is a moderate water demand, and Laburnum is low, but if you are on shrinkable clay, it probably is being affected in this drought. You might find it lifts back a bit when the clay rehydrates. Worth keeping the trees heights quite low.  

orangecrush

They’re both relatively short, as we have telephone wires - they’re both about up to the height of the guttering, but I think about 40 years old, according to neighbours. 

stuart45

Going by the NHBC calculator if the soil is high shrinkable clay with an Ash tree within 5 metres and at it's mature height of 23metres the foundation needs to be 2 metres deep, although yours is not at this height.
An SE will probably tell you that the trees are causing this issue. He may well fix some tell tales to the cracks to monitor the movement. You could do that yourself, as tell tales are cheap enough.

orangecrush

Brilliant thank you, that’s so helpful. I’m going to get some SE quotes and see if it’s worth going down that route or just straight to the insurer. 

Alderbank

It might seem unfair but your insurer will (almost always) increase your future premiums simply for asking about subsidence.

jonnydeppiwish!

I’d almost be tempted to leave it for a bit longer and see if the cracks change in size over a 6-12month period. Do you have any drains running underneath there as well?