Subsidence, settlement and heave
The report mentions clay and a bay that has dropped. Has a soil sample or a root identification been taken?
No. Neither a soil sample nor a root identification has been taken. The report mentions clay and a bay that has dropped. That records movement and names ground as context. Clay can shrink as it dries, and roots can add to that drying. Mentioning those ideas is not a laboratory result. This visit did not bore the soil, test its moisture or identify a root. The dropped bay is a structural observation. The mechanism in the ground remains unproved.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Bays are sensitive because they project and often sit on their own base. On clay, seasonal shrinkage and nearby plants are common lines of enquiry. They stay enquiries until someone samples the soil and, if roots are found, identifies the plant. The surveyor can see the dropped bay, cracks at the junction and vegetation in the garden. Seeing a shrub is not a root identification. The report has raised clay as context. It has not demonstrated that the ground has dried out under the bay.
Tell your solicitor the bay has dropped and that clay is mentioned without samples. If an engineer or a ground investigation is recommended, that work is still ahead. Do not write to a lender that roots have dried the clay unless a later report says so. Cutting or removing a plant can itself change clay moisture, and the survey has not instructed that. An engineer can decide what sampling is useful. This visit stopped at the mention of clay and the visible drop.
What should you ask your surveyor?
- How does the drop show: in levels, in cracks, or in both?
- Which plants does the report mention, without having identified any root?
- Has a structural engineer been recommended, and not yet instructed?
What are the typical next steps?
- Quote the clay and the dropped bay as untested context, not as a soil result.
- Do not tell a lender that drying by roots has been proved.
- If the cause is needed, instruct the investigation this survey has not already done.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does a tree near the bay prove the drop was caused by roots?
No. A tree can stand beside a bay that dropped for another reason, including a weak foundation or a drain. The survey did not identify a root and did not sample the clay. Nearness is context. It is not a mechanism. Keep the tree as a garden fact until a proper identification says it is involved.
Will one soil sample settle the question?
Not necessarily. One sample may show the ground at that spot and still miss moisture change, roots elsewhere or the depth of the foundation. The survey has taken none. An engineer should design any investigation. Do not expect a single sample to close a movement question the report left open.