Damp and moisture meters
No cavity tray was seen where a porch roof meets the main wall and the bedroom ceiling above is stained. What junction is the stain pointing at?
The stain is pointing at the junction where the porch roof meets the main wall. No cavity tray was seen there, so water running down the cavity, or off the porch abutment, has no seen tray to throw it clear of the inner leaf. The bedroom ceiling above is the room that lines up with that junction. The survey has recorded the missing tray and the stain. It has not opened the wall to prove the path drop by drop, and it has not said the stain is a roof leak somewhere else. The porch junction is where the mark is aimed.
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?
Where a roof meets a cavity wall, a cavity tray should catch water and lead it outside. Without one, water at the abutment can cross to the inner leaf and show on the ceiling of the room above, which is this bedroom. The stain is not a random mark in the middle of that ceiling. The surveyor did not see a tray. They also did not strip the abutment or test the wall ties. The junction is identified by where the stain sits, not by a wall taken apart.
Ask a builder or a roofer to confirm whether a tray is missing at that porch junction and what should be built in, as a separate look. Tell the solicitor the bedroom stain lines up with an abutment where no tray was seen. Do not start with a general roof replacement, and do not start with injection of the bedroom wall. The survey has not specified either. The junction is the porch roof meeting the main wall.
What should you ask your surveyor?
- Was no cavity tray seen at the porch abutment?
- Does the bedroom stain line up with that junction?
- Were the wall ties left untested?
What are the typical next steps?
- Read the stain as pointing at the porch-to-wall junction.
- Ask a roofer to confirm the missing tray before wider roof work.
- Do not treat the ceiling mark as a specified injection job.
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
If the porch tiles look even, is the tray there?
Even tiles do not show a cavity tray in the wall. The survey did not see a tray where the porch roof meets the main wall, and the bedroom ceiling above is stained. A tidy covering on the porch can sit over a junction that was never trayed. The stain is aimed at that junction. The tiles are not the tray.
Does this ceiling stain prove the chimney is the cause?
Not this stain. The survey links it to the porch junction where no cavity tray was seen, not to a chimney. A ceiling can be marked from more than one place in other houses. Here the note is the abutment. Do not move the investigation to a stack the report did not blame. The junction is the porch roof against the main wall.