Possible subsidence to extension. How concerned should I be? Please help!

adamadam123

Hello,

I am in the midst of purchasing my first home. The property is a 3 bed semi detached.

The property was extended (single storey) at the back.

Directly under the left side of the window (on the outside) in the extension, you can see some zig zag cracks (see photo below)

We had a survey report and it says further investigation is required (see photo of comments below). Also, the roof is in terrible condition with sitting water, and inside the room, there is cracking along where the ceiling meets the wall, not sure if this is related to the possible subsidence or separate issue (see photo of surveyor's comments for that too below). 

Is the crack in the extension and the thin crack in the ceiling enough to suggest that subsidence has occurred? Or could it just as likely be something more harmless?

We’re looking at getting a structural engineer out, but we’re not sure about paying out for this if subsidence seems quite obvious…..

I'm aware that subsidence and underpinning can lead to various difficulties, particularly with insurance and reselling the property. Would underpinning in the extension alone lead to such problems, or would issues only arise if the main building needed underpinning?

What could it mean for us if we purchased a house with a crack in it, even if it hadn’t been officially recorded as subsidence? The mortgage has already been approved for the property. 

 Any advice really would be greatly appreciated.

Many thanks

Adam

 

Section62

adamadam123 said:

Is the crack in the extension and the thin crack in the ceiling enough to suggest that subsidence has occurred? Or could it just as likely be something more harmless?

We’re looking at getting a structural engineer out, but we’re not sure about paying out for this if subsidence seems quite obvious…..

I'm aware that subsidence and underpinning can lead to various difficulties, particularly with insurance and reselling the property. Would underpinning in the extension alone lead to such problems, or would issues only arise if the main building needed underpinning?

What could it mean for us if we purchased a house with a crack in it, even if it hadn’t been officially recorded as subsidence? The mortgage has already been approved for the property.

With a single-storey flat roofed extension the probability is that demolition and rebuilding would be more cost effective than attempting underpinning - the only issue in this case is the neighbour's extension apprears to be 'attached' and that might limit the options.

There is a very large area of flat roof with that property - and it clearly isn't in a great condition. That %age of flat roof might make getting insurance less easy, before you mention the cracking.

There's a difficult choice to be made here.  You either need to budget for full replacement of the roof and rebuilding the defective walls (but hope it will be cheaper than that), or else look for a less problematic property.

canaldumidi

The roof is a mess. All that water sitting there. Either it was built with insufficient 'fall' (slope) tomake water run off intothe gutteres, or the roof has sagged. Either way it needs stripping off and re-roofing. So start by budgetting for that

The cracks could be connected with the roof problem, could be, as suggested, drainage (there's a gutter downpipe on the wall with the cracks - where does that go?), or could be subsidence

If you are willing to proceed knowing the roof needs re-doing (either from your savings or negotiating a price reduction), then next step is CCTV and/or structural engieeer.

HobgoblinBT

Don’t buy this house, as subsidence might cost you a fortune.

I say this from experience.  We purchased our house in 1989 with no signs of subsidence. Our side extension suffered substantial cracking from “Heave” (opposite of subsidence) a couple of years later following the local council cutting down a 40ft poplar tree within 10 meters of our house.

Fortunately, the photos of the house from the estate agents confirmed there was no sign of damage when we purchased the house so the insurance company paid for underpinning of the extension with a 1m deep concrete raft supported by around 20 5m deep concrete piles.

The insurance pay out amounted to around 30% of what we bought the house for, and was more than the house insurance premiums that we have paid over the following 25 or so years!

The roof looks bad as well.

There are signs of damage already so the OPs insurance will not cover any damage. They might even restrict cover or even decline to cover.  My advice to the OP is to find another house.  

Unfortunately, the vendor may have problems selling this house.  Sounds like it may be worth the vendor claiming under their own insurance, or selling the house to a cash buyer at auction.  

stuart45

Is this extension a converted garage?

Doozergirl

stuart45 said:

Is this extension a converted garage?

My thoughts too.  Is it even double skinned?  By the marked lack of window reveals both inside and outside of the extension, I say no. 

That is a lot of substandard build, imo.  It's going to be freezing from the lack of insulation, vulnerable to damp because of being single skinned and even the layout of it means a lot of space not particularly suited to modern living.  

I wouldn't buy it.  

adamadam123

stuart45 said:

Is this extension a converted garage?

Hi, it was a garage conversion, and a new garage was built at the front, and between the two is a kind of a foyer area. Flat roof across all of it. Thanks

youth_leader

As someone who has just had the flat roof blown off my bungalow in Storm Arwen, I'd get a quote for a new flat roof. 

My seller told me she'd had the roof replaced in 2019 and left the invoice for £3,200.  I've just had a quote from the builder to give the insurers for £7K plus VAT without insulation. .  

Rosa_Damascena

youth_leader said:

As someone who has just had the flat roof blown off my bungalow in Storm Arwen, I'd get a quote for a new flat roof. 

My seller told me she'd had the roof replaced in 2019 and left the invoice for £3,200.  I've just had a quote from the builder to give the insurers for £7K plus VAT without insulation. .  

Isn't ceiling insulation mandatory under building regs?

IamWood

I would only purchase the property if it's in a prime location of the town and has the potential to rebuild for profit. I would not bother if not, I'm afraid.

youth_leader

@Rosa_Damascena, the damaged roof wasn't insulated, and the insurers would only only pay out for like for like.  I'm going to pay for the insulation separately.  I'm so glad it's sunny today, I'm finding it so stressful when it rains.