Roofs and flat roofs
A cement fillet replaces soakers where a lean-to meets the wall. Why is the fillet not a lead soaker, and what leak has it not timed?
The fillet is not a lead soaker because it is a mortar band on the face of the junction, not pieces of lead woven with the tiles and turned into the wall. It has not timed any leak: the survey cannot say when water will pass it, or whether water has already passed it and dried. The cement was seen where soakers would normally be. It was not cut out, and no leak was dated from staining, a drip or a history.
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?
Soakers are small lead pieces set between the tiles and covered by a flashing let into the wall, so movement does not open a rigid joint. A cement fillet is stuck to the tiles and the wall. When either moves, the mortar can crack and the crack is a path. The fillet can look complete on a dry day and still be the wrong detail. The survey has not watched a leak through it, and it did not uncover anything hidden behind the cement.
Ask a roofer to price soakers and a cover flashing as the usual detail, and keep that separate from any damp already inside. Tell the solicitor the report identifies a fillet, not a timed leak and not a lead weathering. The home survey did not hack off the cement and did not prove the wall behind it is wet or dry.
What should you ask your surveyor?
- Is the visible weathering a cement fillet rather than lead soakers?
- Did you see cracking in the fillet, or staining on the wall below it?
- Was any leak through that junction timed, or only the detail recorded?
What are the typical next steps?
- Treat the cement fillet as not a lead soaker.
- Ask a roofer to price soakers and a cover flashing.
- Do not invent a date for a leak the survey did not time.
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 fillet has no crack today, is it doing the job of soakers?
No. An uncracked fillet is still mortar on the face, not lead woven into the tiles and the wall. The survey saw cement where soakers would be. It did not call that a lead detail, and it did not time a leak. Mortar can open later. The absence of a crack on the day does not convert the fillet.
Could soakers still be hidden under the cement?
They were not found. The survey recorded a cement fillet in place of the soaker detail and did not cut the mortar away. Anything buried in that junction stayed buried. You should not assume lead is there, and you should not assume it is absent beyond what was visible. The note is the fillet that could be seen.