Age and type of house
The 1930s house is cavity and the porch walls are solid. What damp path in the porch is not a cavity-wall tie problem?
The damp path in the porch is through the solid wall, not a cavity-wall tie problem. The 1930s house is cavity construction. The porch walls are solid, so there is no cavity there for a tie to sit in, and no tie failure to explain moisture in that masonry. Rain, splash, or ground moisture can cross a solid porch wall because the wall itself is the path. The survey has distinguished the porch from the cavity house. It has not tested wall ties in the main walls, and it has not proved the porch is damp inside. The porch is a different construction.
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?
Cavity-wall ties are metal links built into the two leaves of a cavity wall. They are a known issue in some older cavity houses, but they do not exist in a solid porch wall. Treating a porch stain as a tie failure imports a defect from the main house into a wall that was built as one leaf. Solid walls wet from driving rain, from bridged details, or from the ground. It did not open the porch wall, and it did not test ties anywhere.
If the porch is marked inside, ask the surveyor to confirm they are describing the solid wall and not the cavity house. A builder who offers tie replacement for the porch is answering the wrong construction. Tell the solicitor the porch is solid and the main house is cavity, so any later quote should say which wall it is for. Do not commission a wall-tie survey of the porch. The home survey has not tested the ties in the cavity walls either.
What should you ask your surveyor?
- Are the porch walls solid, and the main house cavity?
- Is the porch damp path unrelated to wall ties?
- Have the cavity ties in the main house been left untested?
What are the typical next steps?
- Read any porch damp as a solid-wall path, not a tie failure.
- Keep any tie question, if one arises later, to the cavity house.
- Do not accept a porch quote that assumes ties in a solid wall.
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 main walls have a cavity, must the porch have one too?
No. A 1930s house can be cavity while a later or original porch is solid. The survey has already split them. The damp path in the porch is the solid wall, not a tie in a cavity that is not there. Do not copy the main-wall construction onto the porch. Ties in the house, if they worry you, were not tested on this visit.
Does a dry porch on the day mean the solid wall cannot take in rain?
No. A dry finish on the day does not change the construction. The porch walls are solid, so the path, if rain or ground moisture crosses, is through that wall, not through failed ties. The survey has not proved the porch is damp, and it has not proved it never will be. It has said the path is not a cavity-tie problem.