Roofs and flat roofs
What should you ask if a flashing is dressed so that water can run behind it?
Ask which way the lap faces. Lead or felt turned uphill, or tucked so the free edge points into the weather, sends water behind the flashing instead of over it, which is a dressing fault rather than a missing flashing. A surveyor may see an upturned edge from a window or the ground and will not peel the flashing back on a standard inspection.
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?
Flashings work by laps. The upper piece should discharge onto the lower piece, and the cover should finish so water cannot blow underneath. A sheet dressed the wrong way can look complete from the street and still be a funnel. This happens at abutments, around pipes and where a later patch was stuck on in a hurry. The survey should describe the edge it saw, not invent a lap it could not see.
Redressing one flashing is not a re-roof. There is no RICS price for it. Ask a roofer to say whether the sheet can be redressed or whether the chase and the soakers need to come out too. A home survey does not take those soakers out. If the only evidence is a stain and the edge was not seen, say that the direction of the lap is unconfirmed rather than condemning every flashing on the house.
What should you ask your surveyor?
- Which flashing looks dressed the wrong way, and which did you not see?
- Is the sheet present but reversed, or is it missing?
- Is there a stain inside that lines up with that edge?
What are the typical next steps?
- Ask a roofer to check the lap, not only to paint the flashing.
- Do not smear mastic along an upturned edge and assume the direction is cured.
- Keep each flashing separate in any list you send the seller.
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
Is an upturned lead edge always wrong?
A turn into a chase is normal. A free edge pointing up the slope, so water runs under it, is the fault. Ask which one was seen.
Can felt patches be dressed the wrong way too?
Yes. A patch stuck with the lap facing the weather can channel water. The material does not change the point.