Roof survey checklist: what to check, photograph and note

A roof survey is only as good as the order you work in. Wander about and you will miss the back valley, forget the chimney flaunching and end up writing the report from memory three days later. Work the same route every time and the report almost writes itself.

This is the route we use, area by area. For each one: what to look at, what to photograph, and the words that actually go in the report. Grading sits at the end, because the grade follows the evidence, not the other way round.

Before you get the ladder out

Start on the ground, right round the building. Two laps: one at about ten metres back for the overall shape, one tight to the wall looking up.

Note the roof type, covering, approximate age if the client knows it, and the orientation. Note the weather that day and anything that affects access: conservatory, fragile roof below, parked cars, overhead cables, neighbour's land. If you cannot safely access something, say so in the report rather than guessing. "Not inspected, no safe access from ground level" is a legitimate finding.

Photograph each elevation from the ground, in the same order every time (front, right, rear, left). Those four shots become the context photos that stop the client asking "which side is this?" halfway down page six.

Chimneys and stacks

Chimneys cause more water ingress than almost anything else on a pitched roof, and they are the thing clients least expect to pay for.

Check the flaunching on the top for cracking and loss of bond to the pots. Check the pots themselves for cracks and missing or displaced caps. Work down the brickwork for spalled faces, eroded or missing pointing, and any sign of sulphate attack (vertical cracking, bulging on one face, usually the weather side). Then the junction with the roof: lead soakers and front apron, back gutter, stepped cover flashing. Look for lead that has slipped out of the mortar joints, splits at the folds, sand and cement fillets used instead of lead, and a back gutter that has silted up.

Photograph the whole stack from one side, the flaunching from above if you can get there safely, any cracked brickwork close up with something for scale, and each flashing junction separately. Mark up the photo rather than describing the location in words.

In the report: name the elevation, name the element, say what you saw and what it means. "Rear stack, west face: pointing eroded to a depth of around 15mm over roughly half the face. Rain is being absorbed into the brickwork and will track down to ceiling level in the bedroom below."

Pitched slopes

Take each slope separately and name it by elevation, not "roof 1".

Look for slipped, missing, cracked and delaminating slates or tiles. On older natural slate, look for nail sickness: slates slipping singly across the whole slope rather than in one patch. On concrete interlocking tiles, look for surface erosion, moss build-up in the pans and tiles lifted at the perimeter. Check the ridge and hips for cracked or missing mortar bedding, and whether they are mortar bedded or dry fixed. Check verges for the same. Check the eaves course for sagging, and whether there is any felt or underlay visible and what state it is in at the gutter line.

BS 5534 is the relevant standard for slating and tiling fixing and mortar bedding, and it is worth saying so in the report where a repair is being specified.

Photograph each slope whole, then every defect individually with enough surrounding roof that you can place it later. A close-up of a cracked tile with nothing around it is worthless in six months.

Valleys, abutments and flashings

Valleys are the single most common source of long-running leaks that nobody has traced.

Check the valley type: lead-lined, GRP, fibre-cement or tile-and-a-half. On lead, look for splits at the laps, corrosion from the underside, and whether the lead is too long between joints (long sheets fatigue and split). On all types, look for debris, moss and ponding, and for tiles cut too tight to the channel.

At abutments, check whether there is a proper cover flashing chased into the brickwork or just a mortar fillet. Cement fillets crack; say so.

Photograph down the full length of each valley, then the specific split or blockage. Note the approximate position along the valley so you can find it again.

Flat roofs

Name the covering: three-layer felt, single-ply, GRP, liquid applied, mastic asphalt. Note the approximate age, falls, and whether water is ponding. Ponding on its own is not a defect; ponding plus splitting is.

Check the perimeter upstands and the height of the termination, the drip edge, outlets and whether they have leaf guards, laps and welds for lifting, and blistering or crazing across the field. On GRP, look for crazing at internal corners and movement cracks over joints in the deck. On felt, look for shrinkage pulling the covering off the upstands.

Photograph the whole roof from one corner, each outlet, each upstand junction, and the defect itself. A photo taken in the rain showing where water sits is worth more than three taken in sun.

Gutters, downpipes and parapets

Check for vegetation, standing water, joint leaks, sagging between brackets, undersized or wrongly falling runs, and staining on the wall below. Check downpipes discharge into a gully and not onto the ground. On cast iron, look at the back of the gutter where it meets the wall, which is where it rots first.

On parapets, check the coping stones and their joints, the DPC under the coping if visible, the cover flashing, and the inside face for staining.

Photograph staining on the wall as well as the gutter: it is the evidence that the defect is doing damage.

Rooflights and penetrations

Every hole in a roof is a risk. Check rooflight flashing kits, seals, condensation between panes, and whether the surrounding tiles have been cut and left unsupported. Check soil vent pipes, slate vents, flues and aerial fixings for perished collars and missing weathering.

Loft inspection

If you can get in, do. The loft tells you what the outside is hiding.

Look for daylight through the covering, torn or sagging underlay, staining on rafters and purlins, active drips, rot at rafter feet, split or notched timbers, insulation depth and whether it blocks the eaves ventilation. Look at the back of the chimney breast for salt staining and damp patches.

Photograph staining with the flash on, and photograph the same spot you photographed outside so the two tie together.

How it maps to Cat 1 to 3

Grade each finding, not each area. One slope can carry a Cat 1 split valley and a Cat 3 bit of moss.

Grade	What it means	Typical example
Cat 1	Urgent, acting now	Split valley lining, active leak
Cat 2	Needs work this season	Eroded chimney pointing, slipped slates
Cat 3	Monitor or maintenance	Moss build-up, light gutter debris

The detail of how to word each band, and where to draw the line between 1 and 2, is in our guide to roof survey categories. If you want the whole structure ready made, there is a roof survey report template laid out in this order.

One aside: this is the order Docutrades uses on site, so notes and photos land in the right section as you go and one press turns them into report prose. You can try that on a real job during the 14-day trial, which includes five reports.

Two habits worth keeping

Write the note at the defect, not in the van. And always record what you did not inspect and why, including the weather. Both protect you later.

Pick one of your next surveys and run it in this order, start to finish, without shortcuts. Then compare the report you produce with your last one and keep whichever structure the client understood faster.