Non-standard construction
A no-fines wall has been coated with external insulated render. What of the concrete has that coat stopped the survey seeing?
Not the concrete surface. External insulated render on a no-fines wall has stopped the survey seeing the concrete underneath. The coat covers the face of the wall, so cracks, patches, previous repairs and the concrete itself are hidden. The survey can see the render: its finish, its joints, and any crack in the coat. It cannot see the no-fines concrete through that build-up. Do not read a tidy render face as a clean bill for the concrete, and do not read a render crack as a measured defect in the wall behind.
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?
No-fines concrete is the structure. Insulated render is a later coat. Once the coat is on, a visual survey is looking at the coat. It does not core the wall, and it does not peel the insulation back as part of a normal inspection. Anything you need to know about the concrete's surface has to wait for a look that removes or opens the covering, which this visit has not done. Say that limit in plain words. Covered is not the same as inspected.
This construction is not a conventional cavity you can talk about as if ties and a leaf were there to see. Unusual concrete construction is a reason to discuss a more detailed survey, and still that survey cannot claim what it cannot see. Ask the firm to state no-fines where that is known, and to state that render concealed the concrete. Do not let a lender pack say the wall was examined if only the coat was walked.
What should you ask your surveyor?
- What of the no-fines concrete was visible, if any?
- Are you reporting cracks in the render, or claiming cracks in the concrete?
- What would have to be opened before the concrete face could be seen?
What are the typical next steps?
- State that insulated render concealed the no-fines concrete.
- Do not describe the concrete as inspected through the coat.
- Keep render defects labelled as defects in the render.
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 sound-looking coat mean the no-fines concrete is sound?
No. The coat has stopped the survey seeing the concrete. A tidy face is not an inspection of what is underneath the insulated render.
Can you treat this wall as an ordinary cavity because it has been insulated?
No. Insulation on the outside is a coat. It does not show you a cavity, and it does not reveal the concrete.