ChrisL69

So I'm having real difficulty engaging a structural engineer to assess the dropped slab. Most have refused to consider the job, but a couple have chatted on the phone. Two have said it will just be poor compaction under the slab and not to worry unless there is a crack. One has said a full site inspection is essential at great cost! My father in law has lifted the carpet today and taken photos of the floor. The drop is 10-15mm in the corner and there are surface cracks at right angles to the drop. The cracks are level and very shallow. The floor sounds noticeably hollow in the corner and the walls reverberate when the floor is stamped on. I have attached photos for any shared expertise please... Thank you all. plan.pdf

Thank you all for all the advice. As far as I can tell there are no drains or water mains anywhere near the affected area. The walls aren't affected so the drop is isolated to the slab. There is the evidence of a tree that was once close by, and the surveyor has highlighted dangers from other large shrubs a few metres away, and the soil is clay so I am thinking possible desiccation and/or a void caused by the tree roots rotting away. I am also suspicious of the additional radiator (making three very close together) and any pipework with joints that have been chased into the concrete floor.

That would be my preferred plan, but the budget doesn't stretch nearly that far. I'm thinking right now that if the walls aren't affected then the problem must be fairly minor....

No he just looked at the gap under the skirting and stamped on the floor. Unfortunately we’re moving from 150 miles away so are reliant on the surveyor and vendor.

Thanks for the thoughts. No cracks anywhere inside or out, and there hasn’t been any redecorating for many years so they haven’t been hidden with filler. There has been an extra radiator put in at some point where the drop is, and it looks like the pipes are within the concrete floor - could that be relevant?

Hello. First post here so be gentle please 🙂 We are near completion of a house purchase built on clay soil in Norfolk that we are taking on as a restoration project. It is a lovely architect designed 1969 house in a quiet village. The survey (RICS 2) said everything we expected, but also said the floor in the corner of the living room has dropped and is hollow. He marked it as a 2 in severity and gave no further comments. When I spoke to him he said it has dropped by 10mm over an area covering about 2m x 2m and needs investigating before exchange. He said a drain survey is the next step - there are no drains anywhere near that part of the house so we are assuming drain damage is unlikely to be the cause. There is evidence that a tree located about 4m from that corner of the house was cut down in throat few years (the stump is about 30cm diameter and is weathered), and 14 years ago (Google Street View) was about 12 feet tall with a canopy of 3 m or so. There is no cracking or evident movement in external walls. The property owner died a couple of years ago so we cannot ask her the history, and the executors aren’t replying to questions at the moment (presumably they don’t know). So my questions for experienced folk (and any SE reading) are: 1. Is this subsidence? The surveyor wouldn’t say the word directly. 2. Is it likely that the tree has dedicated the soil and no further movement will occur? 3. Do we need a drain survey if the nearest drain is at the other side of the house? It only has foul drainage, with surface water draining into gravel soak aways. 4. Should we ask for a price reduction, and if so how much? 5. Can we just assume everything is stable now the tree has gone and level the floor? 6. Is there anything we might be missing? 7. Are we worrying unnecessarily? The floor drop can be seen in the attached pictures. The surveyor did summarise that the house is a good purchase provided we are prepared to spend some money on it. Vague advice… Many thanks in advance for reading and replying.