Roofs
What do roof defects mean in a home survey?
A RICS roof comment covers what the surveyor could see of the covering, the junctions and, with safe access, the roof space. The rating records urgency, not a price. Leaking valleys, failed flashings and rotten timbers matter more than a tired dry covering. If the loft or flat roof was not seen, NI is a gap, not a pass.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless a source says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What part of the roof does a home survey actually see?
The surveyor looks from ground level, from windows, and from any safe ladder or hatch their level and their judgement allow. RICS says Level 2 and Level 3 include a more extensive roof-space inspection than Level 1, and that Level 3’s visual inspection is longer again. Nobody is required to walk a fragile covering. If they could not see a slope, the report should say so. Binoculars and a dry day are not an x-ray.
Inside, they want the loft: the underside of the covering, the underlay or felt, the rafters, the party wall and any staining. No hatch, a latched hatch in a tenanted flat, or insulation buried to the top of the joists can all stop that. Those are NI conditions. A brand-new felt mentioned from the landing, without a crawl, is a limit. Ask how much of the void they entered.
Which roof defects are urgent, and which are maintenance?
Water that is already inside the structure is urgent. RICS’s rating 3 is for defects that are serious or need repair, replacement or investigation urgently, including where delay risks severe long-term damage. A valley that is dripping onto timbers is that kind of defect. So is a chimney flashing that has opened above a stained ceiling. A covering that is old, mossy and still doing its job is often a rating 2: it needs replacing in the ordinary run of maintenance, not tonight.
The junctions fail before the field of tiles. Flashings, valleys, abutments and parapet gutters are where surveys earn their fee. A missing tile on a dry slope is a repair. A saturated party wall in the loft is an investigation. Flat roofs fail quietly: the felt can look tidy from a bedroom window and be split at the upstand. If the surveyor could not get onto it, do not read silence as approval. Read NI, then look at the ceiling underneath.
Can you price a new roof from the rating?
No. A re-cover of a small terrace and a re-cover of a complex roof with dormers, valleys and a chimney are different contracts. The condition rating does not contain a square-metre rate, and we are not inventing one. RICS tells you to obtain written quotations for rating 3 work before legal commitment. That applies cleanly to a roof the surveyor says needs urgent repair or replacement. Get the quote from a roofer who has seen the slopes the surveyor saw, with the paragraph in their hand.
Ask the quote to separate making it watertight now from replacing the covering later. Sellers and buyers often split those. Also ask whether the underlay and battens are included. A price for “tiles only” on a roof whose felt has perished is not the cost of the job the loft is describing.
What about asbestos sheets, and sagging roofs?
Corrugated sheets on garages and lean-tos are often asbestos cement. The Health and Safety Executive publishes asbestos-essentials sheets for working with asbestos cement, which is a way of saying the material is real and the work has a method. A surveyor who suspects it should say so and tell you not to disturb it. They do not take a sample as part of a Home Survey. Intact cement sheets are not the same hazard as broken debris. Do not smash them to “check”, and do not pay for a new garage roof without asking how the old sheets will be disposed of.
A sagging ridge or a spread eaves is a structure comment, not a tile comment. It can mean the roof is pushing the walls, or that timbers are undersized or cut. That is a Level 3 sort of discussion and, where the surveyor says so, an engineer or a roofing contractor who understands structure. Do not let a re-tile quote ignore a spreading roof. The new tiles would sit on the same problem.
Common questions
The loft is marked NI. Has the roof passed?
No. NI means not inspected. If there is no staining elsewhere and the outside covering looked orderly, the practical risk may be limited, but it is still a gap. If ceilings are stained or the surveyor says they are concerned, RICS expects the report to say what further investigation is needed. Book a return visit with a hatch key before you treat the roof as done.
Is moss a defect?
Moss holds water and can block gutters. It is not, by itself, a failed roof. Surveyors mention it because gutters and tile surfaces suffer. A rating should follow the damage, not the greenery. Clearing gutters is maintenance. A slipped row of tiles underneath the moss is a repair.
Why do chimneys get their own rating?
They stand in the weather, the flaunching cracks, the pots lean, and the flashing at the base lets water into the loft. A redundant chimney can still soak a party wall. The rating is about the stack you can see and the junction, not about whether you light fires. Ask if they could see the stack in the loft as well as from the street.
Should a flat roof be replaced just because it is twenty years old?
Age is a clue to the material, not a rating. Some coverings fail earlier, some last longer, and the surveyor may not know the date. What matters is cracking, ponding, failed upstands and stains below. If they could not see the surface, say so in the follow-up and get someone up there safely. Do not pay for a replacement on a birthday the report did not state.
The seller says the leak is fixed. Does the rating still stand?
The rating stood on inspection day. A later repair needs invoices and, if the water reached timbers, a look at whether they dried. Paint on a ceiling is not a repair. Ask your solicitor to obtain the paperwork, and ask the surveyor whether they need to re-inspect before you rely on it.
Are roof windows and dormers a separate risk?
Yes. They puncture the covering. Leaks start at kerbs, flashings and cheeks. A sound field of tiles does not vouch for a dormer. If the survey rates the dormer and not the main slope, believe the distinction and price the dormer.
What does torn underfelt mean?
The layer under the tiles is a second line of defence and, when it tears, wind-driven rain and snow can reach the timbers and the ceilings. It does not always mean the tiles must be stripped this month. It does mean the loft is more vulnerable until the covering is properly renewed. Ask whether they saw daylight, staining, or only a brittle historic felt that is still continuous.
Will a roof quote include scaffolding?
Ask for it to be stated. A terrace with a pavement, a rear slope over a conservatory, and a three-storey townhouse are different access problems. The survey will not price the scaffold. A quote that is silent on access is not finished. This is not a typical-price claim. It is a question for the estimate in front of you.
Is a Level 1 roof comment enough?
Only as a basic overview. RICS says Level 1 is less extensive and will not generally advise how to manage defects. If the roof is complicated, old, or already leaking, that is part of why Level 2 or Level 3 exists. You can still use the Level 1 as a prompt to get a roofer, but do not expect repair options the product was not written to give.
Sources
- House surveys: the costs, types and benefits of an RICS home survey — RICS
- Scope of inspection: Home Survey Level One — RICS
- Description of the RICS Home Survey Level 3 (condition rating definitions) — RICS
- Asbestos essentials (including textured coatings and asbestos cement) — Health and Safety Executive
Key facts
- What is seen
- Coverings, flashings, chimneys, gutters and valleys from safe vantage points. The loft only where access is safe. Level 1 is a less extensive roof inspection than Level 2 or 3.
- What is not seen
- RICS: Level 1 and Level 2 do not remove secured panels as standard. Hidden timbers stay hidden unless there is a hatch and a safe crawl.
- Urgency
- An active leak into the structure is the sort of defect RICS puts in rating 3 territory: serious or urgent. A worn but watertight covering is often maintenance.
- Asbestos cement
- Garage and outbuilding sheets may contain asbestos. HSE publishes task sheets for asbestos cement. Do not break or scrape them on a hunch. A surveyor flags suspicion. They do not sample.
- Flat roofs
- Often excluded when they cannot be seen safely. NI plus staining on the ceiling below is a leak investigation, not a pass.