Roof photos: what the common faults look like

The easiest fault to spot is a gap. A missing tile or slate shows as a dark rectangle with the felt or battens visible beneath it. Slipped ones are subtler: look along a course and the tail line, the bottom edge of the row, should run straight. When a slate has sunk by a hand-width or less, its tail hangs lower than the row, and often a pale stripe of fresh surface above it where it used to sit.

Cracked tiles show a fine dark line, sometimes with a wedge missing from one corner. On a clay or concrete tile, a crack usually means someone has trodden on it or something has fallen on it. On natural slate or stone, look for a flaky, layered face. That is delamination, where the stone separates into thin sheets and water begins to find its way through.

A close photograph of a single slipped slate is rarely enough on its own. Good reports pair it with a wider shot so you can see where it sits on the slope and whether others around it are moving too.

Mortar fails by cracking and falling out. In a photograph it appears as a dark seam with a crumbly edge, sometimes with a grey scatter of fragments in the gutter below. At a ridge (the line where two slopes meet), a bedded tile with a crack running beneath it, or a visible gap between the tile and the mortar, tells you the bond has gone. Re-bedding or repointing a ridge or hip is typically priced at £200 to £400, MyBuilder 2026, and a dry ridge is about £40 to £60 per metre.

On a dry-fix roof, mortar is not the issue. Look instead for ridge tiles that have drifted out of a straight line, end caps that have popped, and plastic parts that have gone brittle and chalky. BS 5534:2014 treats mechanical fixing as the basis for ridge and hip tiles, which is why a bedded ridge with no fixings at all is worth flagging. The roof condition report explains how these findings are set out in the written document.

Flashing means the lead, zinc or other metal that seals the roof to a chimney or wall rising through it. A valley is the channel at the meeting point of two roof slopes, where their run-off joins. Both are places where water is concentrated, so faults here do real damage.

In photographs, healthy lead lies flat and dark grey, with neat folds. Warning signs include:

• A flashing lifted away from the masonry, leaving a visible slot.
• Cracks along a fold, which come from the metal being worked too hard or from years of movement.
• Sealant or mastic smeared along the top edge, which often means a repair has been made in place of a proper chase and dressing.
• Pale, weathered lead with white or light-coloured patches, which is normal oxidation and not itself a fault.
• Stepped flashings on a gable wall that no longer follow the courses of the brick or stone.

At a valley, check for debris, moss in the channel, and tiles at the edges that have been cut unevenly. Lead flashing repairs are typically £50 to £70 per metre, with stepped flashing at £80 to £120 per metre, Checkatrade 2026, excluding VAT.

Green cushions of moss in the laps are the most frequent thing to see in a survey photograph. A thin film on a north slope is cosmetic. A thick mat that raises the edge of the tile or fills the gap between courses holds water against the surface and can feed frost damage.

Dark streaks running down below a chimney or a vent pipe are worth a second look, because they can show water running from a failed joint rather than simple weathering. Orange or yellow lichen is generally harmless to the covering. White crystalline deposits on masonry, called efflorescence, show that moisture is moving through the wall or chimney stack.

Cleaning is done by hand scraping or soft washing, not an aggressive pressure jet, which MyBuilder warns may damage delicate tiles. Scraping is typically £5 to £10 per m², according to the same 2026 guide.

Gutters appear in almost every roof photograph, and their faults are visible. Look for plants growing from the joints, a gutter that dips in the middle where a bracket has let go, stains on the wall behind a joint, and water marks on the fascia board where overflow has run.

If water is regularly spilling over a gutter, tiles at the eaves and the wall below suffer. The eaves are also where felt should lap into the gutter; a photograph showing felt hanging loose or cut short is a finding in itself. Our underlay failure signs answer explains how that looks.

When our surveyor sends photographs of your roof, each image should show one thing, labelled with its location, and be paired with a wider view. Ask for both. If a report claims a defect but offers only a distant shot, ask for a close-up, and where all you have is a close-up, ask which part of the roof it came from.

If you are buying a property and have a seller's photographs to go on, remember that a photograph is a snapshot. It cannot show the loft or the inside of a flashing. For a house under an auction timetable, ask for the photographs first and the written note after, as that is the quickest route to a decision.

Photographs of your roof come with every survey, and a repair quote follows afterwards; the work itself carries a 10-year workmanship guarantee in writing. The roof inspections hub at roof inspections and surveys lists what each type of visit covers.