Roofs and flat roofs
What are sarking boards, and why does a Scottish roof survey read differently from an English loft?
Sarking is boarding laid over the rafters under the tiles or slates, common on older Scottish roofs. The underside is timber boards, not the open felt an English surveyor often sees. A Home Report still only records what was visible. It does not mean the boards have been tested for rot, and an English Level 2 habit of “looking at the felt” may not apply.
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?
mygov.scot describes the single survey as a visual inspection by a chartered surveyor. Where the loft is boarded, the surveyor sees boards, nails and stains, not the underside of every slate. Damp marks on sarking can be a driving-rain issue, a nail problem, or condensation. The report should say what was seen and what was not opened. England and Wales more often have underlay and no boards. Do not copy an English felt sentence onto a boarded Scottish roof.
The RICS consumer material on Home Reports is about what a purchaser is given in Scotland, not a method for proving rot. If the single survey flags the sarking, ask what access there was and whether a roofer needs to lift coverings. Repairs are still a quote, not a figure in the Home Report. Buyers in England should not assume their loft will look the same.
What should you ask your surveyor?
- Did you see boards, felt, or neither?
- Were the boards stained, soft, or only dusty?
- Is any recommendation about the covering, the boards, or both?
What are the typical next steps?
- Read the Home Report limit on the loft before you compare it with an English survey.
- Do not ask a local roofer to “replace the felt” if the roof is boarded.
- If the boards are rated for repair, get a roofing quote that says whether slates must come off.
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 sarking mean the roof cannot leak?
No. Boards can hold water and hide a failed covering. They are not a guarantee.
Is sarking a defect by itself?
No. It is a form of construction. The defect, if there is one, is what the surveyor saw wrong with it.