Roofs and flat roofs
Where a report pairs creasing tiles with the verge beside the stack, what stays open about an undercloak that has dropped?
What stays open is the dropped undercloak beside the stack, and whether the verge is still supported once that course has moved. The report paired creasing tiles with the verge it could see. It has not decided that the tiles are holding the edge, that the undercloak can be left, or that water is entering at the stack. A ground view can show a gap or a sag. It cannot rebuild the verge or test the bedding. The creasing tiles and the fallen undercloak are related, but neither has been given a repair verdict.
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?
Creasing tiles are the flat courses under a verge that tilt water back onto the roof. An undercloak is the layer beneath the edge of the covering. If it drops, the verge mortar and the tile ends lose support, often beside a stack. The surveyor can see the drop from the ground. Seeing it does not show how far the gap runs under the slates, or whether the stack flashing is involved. The pair of words is a defect to follow, not a finished specification.
Ask the solicitor if the seller has had the verge or the stack repaired, and keep any invoice history apart from this note. A roofer needs safe access to see the undercloak, the creasing tiles and the flashing together. The home survey has not opened that edge and has not said the stack is the cause. Do not treat a neat-looking tile face away from the verge as proof that the dropped course does not matter.
What should you ask your surveyor?
- Where has the undercloak dropped relative to the stack?
- Were the creasing tiles seen to be loose, or only identified?
- Did the view include the flashing, or stop at the verge edge?
What are the typical next steps?
- Treat the dropped undercloak as unresolved.
- Ask the seller about earlier verge or stack repairs.
- Use a roofer if the edge must be specified.
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
Will repointing the verge mortar close the gap?
Repointing covers the joint that is visible. It does not put a dropped undercloak back or show whether the creasing tiles still have a bed. The survey did not recommend a mortar-only repair and did not test the edge. A roofer should see the support before anyone fills the gap.
Is the stack itself included in this verge note?
The stack is the landmark for where the verge was seen. The note does not inspect the flue, the pot or the flashing as a chimney report. Those are separate if they appear elsewhere. Here the open question is the undercloak and the creasing tiles beside that stack.