The short answer
Snagging a new-build roof means checking the finished roof for faults before the builder's defects period runs out. Look for slipped or cracked tiles, gaps at ridges and verges, untidy lead and flashings, poor mortar work, blocked gutters and daylight or damp in the loft. Record everything with dated photos and send a written list to the builder. An independent roofer can inspect the details you cannot reach, and give you evidence to back your list.
Why a new roof can still have faults
New does not mean perfect. A new-build roof is put on quickly, often by several crews over several weeks, with other trades walking over it afterwards. Tiles get chipped, ridge pieces are knocked, and details such as flashings are sometimes finished in a hurry. A fault may be minor, but a minor fault left alone through a winter can become a leak.
The time to find them is early. Most new homes come with a builder's warranty and a defects period during which the builder must put right faults caused by poor work. The paperwork that came with your house sets out how long that period is and how to make a claim. Check it before you start, and keep a copy of every message you send.
It is also worth knowing what is not a defect. Normal weathering, minor colour variation between tiles and small hairline marks in mortar are not usually grounds for a claim. A good snagging list sticks to real faults and is specific about them.
Weather during the build matters too. A roof laid in wet or windy conditions can have underlay that has been lifted or battens that have swollen, and these only show later. Houses finished in a rush before a sale deadline are worth a closer look than those completed at a steady pace.
What to look for from the ground and the loft
Start outside with binoculars. Check that the tiles sit in neat, straight courses and that none is cracked, chipped or out of line. Look at the ridge and hip pieces, where mortar or dry-fix parts should be tidy and complete, and at the verges and eaves. Lead or other flashings round chimneys and abutments should be neatly dressed and fixed, with no gaps or loose edges. Gutters should fall to the outlets and have no sagging or missing brackets.
Inside, take a torch into the loft. Look for daylight through the tiles, which shows gaps. Check that the underlay is lying flat and has been trimmed properly at the eaves, and that insulation is in place without blocking the vents. Look for any damp on the timbers, even in a dry spell, and for stray debris such as offcuts, which can block the eaves.
Roof windows, vents and extractor outlets are common weak points, because other trades cut into the roof for them. Look at the way each is sealed.
Ask whether any roof tile was changed or added after the scaffold came down. Late repairs are often fitted without a proper ladder set-up and can look slightly different in colour. Also check the area under any satellite dish, aerial or solar fixing, where holes are made late in the build.
Recording and reporting what you find
Make a clear list. Number each item, say where it is, describe the fault and attach a dated photo. Use plain language and avoid guessing at causes. Send it by email to the builder or the site manager, and keep the reply. A short, factual list is taken more seriously than a long, angry one.
Follow up if nothing happens. Note when you reported each item, and when it was fixed. If a repair is made, check it afterwards. A tile replaced by someone in a hurry can be as bad as the one it replaced. Our guide to the roof inspection checklist gives a longer list of the points to cover.
If a leak appears, report it at once, with a photo and the time, and do not wait for the next scheduled visit.
Keep the reply emails and the date of each fix in one folder. If the builder's warranty provider needs to step in, a clean paper trail is the best evidence you can offer.
When to bring in an independent roofer
A snagging list from the ground catches the obvious. A roofer can go up, lift the edge of a flashing, look at fixings and examine the loft with experience. That is valuable where you suspect a fault but the builder says there is none, because an independent report with photographs is hard to dismiss.
Our survey is free, and we photograph each fault and give you a plain written finding. If repairs are needed, any work under the builder's warranty is theirs to do, and we advise you on what to ask for. For work outside that, a fixed written quote follows. See our roof inspections in Basingstoke page for more on the service.
If you plan to add solar, a loft conversion or a roof window, have the roof checked first so that new work does not undo the warranty on the old.
Every roof is different. A free survey with photos settles it for yours.
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