The short answer
Walk round the house four times a year and look up. Look for slipped or cracked tiles, open joints along the ridge and verge, lifted flashing, blocked or dripping gutters, moss, and stains on the ceilings inside. Binoculars and a phone camera do the job from the ground. Never climb onto the roof or lean a ladder on the gutter; if you spot a fault, photograph it and call a roofer.
A simple check for each season that you can do from the ground, with binoculars and a camera, and no ladders on the roof.
Spring: after the winter
Spring is the time to look for what the winter did. Stand back at the front and rear of the house and scan each slope. You are looking for tiles that sit lower or higher than their neighbours, gaps where a tile has gone, and a ridge line that is no longer straight. A pair of binoculars brings the detail close without leaving the garden.
Check the chimney as well. Look for a crumbling stack, leaning pots, or grey lead where the stack meets the roof that looks lifted or split. The small mortar cap on top is called flaunching, and cracks in it let rain run down the flue. Our guide to chimney flaunching repair explains what it does.
Then go inside. Take a torch to any ceiling below the roof, and look for fresh brown rings or paint that has started to bubble. A stain that is still damp after a dry week suggests a live leak. Photograph everything with the date, because a series of pictures over the seasons shows whether a problem is growing.
Summer: gutters and the covering
Dry weather is a good time to look at the gutters, and at the roof covering when the light is clear. From the ground, check that gutters sit level and that joints are not stained or dripping. Plants growing out of a gutter mean it is holding silt, and silt means overflow in the next downpour. Look at the fascia boards behind the gutter, too. Paint that is peeling or timber that looks soft needs attention.
Moss on a tiled roof is common, and a little does no immediate harm, but thick moss holds water against the tiles. Marley does not recommend blasting a roof with a powerful jet wash, since the force can wear the face of a slate or tile and shorten its life. HSE also warns householders off biocide products meant for trained users, so leave any cleaning treatment to someone qualified to apply it, and be wary of a cleaner who offers to blast the roof clean. Our page on roof cleaning and moss removal covers the options.
If you want gutters cleared, our answer on gutter cleaning cost gives a guide.
Autumn: before the leaves and the gales
Autumn is when gutters fill. Once the trees have dropped most of their leaves, check that downpipes are clear and water runs away from the walls rather than down them. A downpipe that is dry after rain may be blocked. If you can see a gutter full of leaves from an upstairs window, it needs clearing before winter, and a roofer with the right access can do it safely.
Look at the loft with a torch from the hatch, without stepping off the joists. You are checking for chinks of light coming through the covering, for damp timber, for insulation that has become wet and for droppings or nesting material. If you suspect bats or nesting birds, stop and read bats and birds in the roof before anyone disturbs the area.
Walk round the outside once more with the loft in mind. Check that vents, air bricks and soffit grilles are clear of paint, cobwebs and debris, and that no plant is growing against the eaves. A loft with no airflow can grow condensation, which can look like a leak but is a different problem.
Winter: after storms, and what to leave alone
After a gale, take a walk around the house once it is light and safe. Look on the lawn and the drive for broken tile pieces, ridge fragments or sections of lead. Check the roof line for gaps and look at the gutters for sagging. If anything is hanging, keep people clear of the area below.
A leak in winter should be photographed, contained inside the house and reported. Our answer on roof tiles blown off covers storm damage, and the page on home insurance and roof wear and tear explains the claim steps.
Keep a simple log as you go. A notebook or a phone album with the date, the part of the house and a note of what you saw makes the next season's check quicker, and it gives a roofer a useful history if a fault returns.
Leave anything that needs height to a roofer: replacing tiles, resealing flashing, clearing high gutters and repointing. Our visit begins with a survey, with pictures of your roof sent to you, and the written price comes as one total afterwards. To see what a professional checks, our page on what happens at a roof survey lists the checks, and our roofing services in Crawley overview shows what we do.
More on this in Roofers in Crawley: the full guide
Two questions about upkeep
How often should I have a roofer inspect my roof?
There is no fixed rule for homes, but a look every few years suits an older roof, and a check after any severe storm is sensible. Your own seasonal walk-round between those visits catches most obvious faults early. Ask the roofer for photos of what they find, so you can see it too.
Is it safe to clear my own gutters from a ladder?
Only if you are confident at height, with a stable ladder, someone footing it and dry weather. Many falls happen at gutter height. If the gutters are high, have a roofer or gutter specialist clear them, and keep the ladder off the plastic gutter itself.