Condition ratings
A bedroom ceiling sags between the joists. Is that the same rated element as the floor of the room above?
No. A bedroom ceiling that sags between the joists is not the same rated element as the floor of the room above. The sag is in the ceiling finish, often old lath and plaster dropping between the timbers. The floor above is what you walk on in the next storey. Those can be marked apart. Do not repair-plan the upstairs boards because the ceiling below has bellied.
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?
A sag between joists is the ceiling finish leaving the flat line, commonly lath and plaster that has lost its key, or a board that has bowed. The joists may be the lines the sag hangs between, which does not mean the joists have failed. The floor of the room above is the boarding or covering you walk on. It can be rating 1, no repair currently needed, while the ceiling is rating 2, a repair that is not serious or urgent, or rating 3 if the surveyor thinks the sag is serious or at risk of falling. Those are different elements. One heading for the upper floor must not glue them together.
Where the ceiling is rating 3, get written quotations before legal commitment. The what to do now note advises you. It does not invoice the seller to replace the upstairs floor. The backs of the ceiling and the depth of the joists are concealed, and concealed parts are not guaranteed sound, so neither rating is a certificate of the timber. If the upstairs floor was springy or sloping, that is a floor sentence and it should carry its own number. Ask the surveyor which element they rated. A plasterer and a floor carpenter are not automatically the same instruction.
What should you ask your surveyor?
- Is the sag a ceiling rating, and does the floor above have a different one?
- Do you think the finish has lost its key, or that the joists have moved?
- Is the upstairs floor rating 1, or was it not what this sag is about?
What are the typical next steps?
- Keep the ceiling sag off the upstairs floor rating.
- If the ceiling is rating 3, get written quotations before you commit.
- Ask which trade the surveyor actually has in mind.
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
Can a lath ceiling be rating 2 while the boards above are rating 1?
Yes. The finish can need ordinary repair while the floor needs nothing now.
Does a crack at the cornice make them one element?
No. A cornice crack is another line. Ask whether it is decoration or part of the sag.