Chimneys and parapets
What should you ask if the oversailing courses on a chimney are cracked but the pots look straight?
Ask about the projecting brick courses, not only the pots. Those courses throw water clear of the stack, and if they are cracked or losing their joints, rain can track into the brick while the pots still look upright, which is not a verdict on the crown mortar and not a lean. A ground-level view may show a gap and miss a fine crack, and the survey does not rebuild the course to test it.
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?
Oversailing, or projecting, courses are the corbelled brick bands you see below the pots on many older stacks. They are not the flaunching on top, and they are not a decorative string with no job. When the projection cracks, water runs back onto the face below. Inside, the symptom can be a high-level stain on the breast, which is a poor match for damp from the ground. A home survey describes the band it could see and should not claim every course was inspected in close-up.
Repair may be repointing, resetting loose bricks, or a larger rebuild if the band has gone. Those scopes differ, and there is no standard price. A straight pot does not postpone a loose projecting brick that could fall. Tell a contractor which face is affected. If the stack is shared, work on the projection can affect the neighbour. The survey does not serve any notice and does not decide who pays. Your solicitor deals with a shared stack.
What should you ask your surveyor?
- Which projecting courses are cracked, and on which face?
- Are the pots a separate, satisfactory comment?
- Did you see loose bricks, or only open joints?
What are the typical next steps?
- Ask for the projecting courses to be included in any stack quote.
- Do not accept “pots are fine” as a survey of the whole stack.
- If a brick projects over a path, do not ignore it because it has not fallen yet.
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 oversailing course the same as a corbelled stack?
A corbelled stack steps out as it rises. An oversailing course is the projecting band. The survey should use the shape it saw, not a textbook label it did not match.
Does render hide these courses?
A thick coat can round them off. Then the survey is describing render, not the brick band.