Basements and cellars
The lightwell drain outside a basement window is blocked with leaves, and the cellar was dry. What has the dry day not cancelled?
Not cancelled by a dry cellar: the blocked lightwell drain outside the basement window remains a water path the dry day has not removed. Leaves in the outlet were seen. The cellar happened to be dry on the visit. Dryness on one day does not prove the outlet will run when rain fills the lightwell. The survey can record both facts. It must not let the dry cellar erase the blockage. The blockage is still the finding the dry day left standing.
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?
Lightwells rely on an outlet. If that outlet is choked with leaves, water has somewhere to collect against the basement window the next time the weather is different. A visit in a dry spell shows the leaves and shows a dry cellar. It does not show the outlet working. Calling the drain cleared because the floor was dry invents a test nobody ran. Rising damp is a different mechanism and is not what this note is.
Clear the description, not the warning: say the drain is blocked, say the cellar was dry, and do not join them with a 'therefore'. Ask whoever maintains the lightwell to clear the leaves and confirm the outlet runs, and look again after rain if the survey has made you unsure. Do not tank the cellar in your head because of leaves, and do not ignore the leaves because of a dry floor. The dry day cancelled neither the blockage nor the path.
What should you ask your surveyor?
- Did you see leaves blocking the lightwell drain, whatever the cellar floor felt like?
- Does a dry cellar on the day prove the outlet runs in rain?
- Is this note a blocked outlet, rather than a rising-damp diagnosis?
What are the typical next steps?
- Keep the blocked lightwell drain on the page beside the dry cellar.
- Do not treat the dry day as cancelling the blockage.
- Have the outlet cleared and checked, rather than inferred from a dry floor.
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 window frame is sound, has the drain been cleared?
No. A sound frame is the frame. The leaves in the lightwell drain are still there, and the dry cellar has not cancelled them.
Does one dry visit after a dry week prove the drain?
No. A dry spell is the worst time to declare an outlet sound. The blockage was seen. The dry day did not test it.