Possible subsidence - please help.

[COSMICDUST]

Hi all

I have scoured through many related threads and feel conflicted on whether my house may be experiencing subsidence. To try and expedite a long story - I purchased a property in 2019, didn't get a survey (previous house purchase had fallen through, my partner was 8 months pregnant, we were living in a flat coming to the end of its tenancy which had rising damp issues) and perhaps made a rash decision and went ahead with the purchase. I did get my brother-in-law who is a builder to check the house, the only comments he made were that some repointing needed doing. We are now very concerned we have purchased a house with subsidence/movement and are considering instructing a structural engineer to assess this. In the meantime, any expertise or advice would be greatly appreciated from this forum's community.

The house was built in 1982. It sits on clay soil. It had an extension built circa 1985, and planning permission was retrospectively granted in 1987 (can't find this on planning portal, but can find two subsequent applications for a single-story extension that were rejected in early 2000s).

When we moved in, we redecorated most of downstairs, which involved stripping wallpaper (feature walls) and there were no visible cracks in the plastering/walls. There were a few hairline cracks in the ceiling, and where the walls met the ceiling, upstairs.

1. We noticed when we moved in their was a dip in the floor, where the extension meets the original walls of the house, although this does not extend across the entire floor - it starts roughly 2 metres in. However, there is also rippling underneath the paper where the extension has been built. The coving has also cracked along the ceiling line in the area of the room that the extension has been built in.

I have attached pictures for reference (please ignore the attempts to hyperlink images):
https://drive.google.com/drive/folders/1FkERSVEY3df5u1Momc63AtgXaqSrP9R_?usp=sharing

a. (dip in carpet)
b. (cracking in coving in lounge, in the same area that extension has been built
c. Rippling in wallpaper where extension has been built
d/e/f. Pictures of outside wall - the bricks are a different colour, has this been repointed previously? Also, presence of some horizontal cracks mid-way up.

Upstairs, the floorboards in all rooms are loose/raised in certain areas, with some sagging in the hallway (I believe the original staircase was built into the living room, and was relocated by the original owners). There is also cracking along the ceiling-line, across stud walls and more solid walls.
g/h. Cracks extending around hallway
i. Cracks in bathroom

I'm aware that all houses experience some movement, and as one member states, houses built on clay literally dance. Any thoughts would be appreciated.

 

[jeds]

The stepped cracking indicates a bit of settlement but there's nothing there that I'd call subsidence. Save your money on the structural survey. If an engineer gives you (an expensive) report saying you've got a bit of settlement - what are you going to do about it? A few routine repairs here and there, a bit of decorating, a bit of re-pointing? You can just do that anyway, you don't need (an expensive) structural engineer to specify that for you. Even the stepped cracking; if the report says settlement/movement, you're not going to rip it down a rebuild it.

Your house is suffering from 1980itis. Poor materials, poor workmanship, poor detailing. Don't worry it's you and millions of others - including me. (1988) It was a period when domestic construction technology was not at its very best. After nearly 40 years the house neds a bit of TLC.

PS, can't suggest anything on the dip in the carpet. Why not take the carpet back and have a look.

 

[^woody^]

Some apparent movement of the extension but the even cracking would suggest some differential movement of the extension for one or more of several possible reasons, but subsidence would be last on the list.

Top of the list would be changes to ground moisture, either naturally (seasonal) or unnaturally (changes to surface water or underground leaks).

For the main house, plaster cracking around edges is generally related to heating and shrinkage, and is common and normal. Floor issues may well be quality of the previous work.

 

[COSMICDUST]

Thank you both for your responses, feel slightly reassured that I haven't just made the worst possible financial decision for me and my family.

Woody, there are two Maple trees within 3 metres of my house that were not there when the house was originally constructed. One is at the front of the house, close to a drain, that lifted my neighbours drive way. This was relaid a month ago, and the offending root was cut away. The other maple tree was at the other end of my house, where the brickwork is a different colour. This was stumped and paved over. Neither tree was bigger than 3 metres. I'm hoping that there is no foundational damage, but probably want to instruct a structural engineer to assess - hoping it isn't ongoing movement and subsidence.

As for the floor, would it be possible to screed and bring to the same level as the rest of the lounge?

 

[^woody^]

Roots don't typically damage foundations. The cause of movement is generally either roots sucking water from the ground, or breaking in to drains to cause leaks which soak the ground.

Monitor the cracking yourself for a year or so. Pay attention to the recent weather (cold spring heating on high for longer, dry wet spring, hot dry summer etc) if you notice the cracking widening or extending. And whether the extension cracking is changing along with the house cracking.

 

[COSMICDUST]

Thank you for your time and advice.

We have a little one and have been working from home, so the heating has pretty much been on constantly.

Secondly, the rippling wallpaper where the extension meets the original wall - any reason for this?