Wall ties and cavity insulation
Perpend weeps are covered by a later render coat. Has the render been raked out to prove the weep is shut?
The render has not been raked out. Perpend weeps covered by a later render coat were seen as joints the coat crosses. Raking the render out would be opening work, and it was not done, so the survey has not proved that each weep is fully shut or that a cavity tray still drains behind the coat. The note is that the outlet is covered. It is not a test of the wall ties and not a view inside the cavity. Whether the weep still works stays open.
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?
Perpend weeps are the open cross-joints that let water out of a cavity, often just above a tray over an opening or at the base of a cavity wall. A later render coat spread across those joints can plug the outlet. From the face, the surveyor sees render where a gap should be. That appearance is strong enough to record. It does not show the tray or the cavity. Proof that the weep is shut would mean raking back to the joint. That was not done.
Tell the solicitor the weeps appear covered and were not opened. A bricklayer or cavity specialist can rake a sample of joints if you need proof, and can say whether ties are a separate question. The survey has not done that raking and has not failed the ties because of the render. Do not tell a lender the cavity is proved undrained, and do not tell them it is fine. Ask for any specification of the render coat so the solicitor can see what was applied.
What should you ask your surveyor?
- Was the render raked out at the perpends?
- Has the survey proved the weep path is fully shut?
- Were the wall ties tested because the weeps look covered?
What are the typical next steps?
- Treat the covered perpends as a visual note, not as opened proof.
- Tell the solicitor the render was not raked out.
- Instruct a specialist if the weep path must be proved.
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
Does a covered perpend prove the wall ties have failed?
No. Covered weeps are a drainage-outlet question. Wall ties are a separate mechanism inside the cavity, and they were not pull-tested. Render across a perpend does not show corrosion or a snapped tie. The survey recorded the coat over the joints. It has not turned that coat into a tie failure. Ties would need their own inspection.
Was the cavity behind the render inspected with a camera?
No. The cavity was not opened and was not camera-inspected. The render was left in place, so the tray and the void behind the covered perpends were not seen. A camera survey, if you instruct one later, would be new work. This report has the covered face only. It does not have a view inside the wall.