Flat roofs take more direct weather than most other roofs. They sit exposed, absorb the sun all day, and don't have tiles or gutters shielding them. After a long summer of UV, thermal expansion and long dry spells, small changes appear that are easy to catch now and much harder to catch once the rain sets in and the leaves start dropping.
None of what follows needs a ladder or a roofer, most of it you can see from an upstairs window, a step ladder to the roof edge, or from a neighbouring balcony. Anything that looks worth a closer look, we'll come and check for free.
The surface itself
A GRP flat roof's topcoat is designed to take UV, but it isn't invincible. After a stretch of hot weather you may notice the finish looks slightly duller, or in older roofs, a faint powdery haze on the surface. That's a mild form of UV wear called chalking, and on a topcoat that's been down for years it's normal. What you're looking for is anything more than that: hairline cracks in the resin, softening where you press it, or the coating lifting at the edges.
If the roof is only a few years old and the surface still looks glossy and consistent, you're probably fine. If it's older and you're seeing any of the above, get it looked at before winter loads the roof with standing water. Our guide on how long a GRP flat roof lasts covers the wear timeline in more depth.
Where water has been sitting
In summer, rain evaporates fast, so ponding spots dry out and leave dusty silt rings behind. Those rings are useful: they show you exactly where water pools when it rains. A few small patches are normal on any flat roof and don't cause a problem. What you're checking for is any large, deep pond that never really dried out, or ponding right up against an upstand or edge, both signs the deck may have started to sag or the falls need looking at before winter.
Flashings, edges and upstands
Every day of summer, the roof heats up and expands, then cools and contracts overnight. Over weeks of that, weaker joints can start to move. Look along the edges of the roof, around any parapet walls, and where the roof meets a pitched wall or a chimney. What you want to see: everything sitting tight and flat. What you don't want to see: lifted edges, cracks where two materials meet, or lead flashings that have pulled away from the mortar. These are the spots where autumn rain finds its way in first.
Debris, moss and gutters
Before autumn drops its first load of leaves, this is your chance to clear whatever the summer has left behind: dust build-up, dead moss patches, pollen residue, the odd tennis ball from next door. Clear the gutters and any outlets too. A blocked outlet is the single most common cause of a "roof leak" that turns out to be perfectly good roof, just water backing up and finding its way sideways into the fascia.
Signs from inside the house
Not all flat roof problems show up on the roof first. Walk into the rooms below and look at the ceiling. Faint brown or yellow rings, damp patches, a musty smell, or fresh cracking in the plaster are all signs water has been getting in over the last few months, even if you haven't seen a drip. Summer is when these show up clearest, because the ceiling has had a chance to dry out and any staining reads as a defined mark rather than fresh damp.
When to call, when to just watch
If everything looks in order, you're done, do the same check again in early spring. If you spot small surface wear on an older roof but nothing structural, a maintenance service in the next few weeks will usually sort it: clean, minor topcoat repair, resealed edges. Our post on how much maintenance a GRP flat roof needs covers what to expect.
If you're seeing standing water that never dries, damp inside the house, or actual damage to the roof surface, that's when to get us out. The gap between now and October is a good window to have work done in dry weather, and it's much cheaper to fix a small problem in September than a leaking roof in November.
Book a free post-summer look
If any of the above rings a bell and you'd rather not climb up to check yourself, we'll come out and look for you. It's a genuinely free visit, no pressure, no follow-up sales calls. If the roof is fine, we'll tell you. If it needs something, we'll give you a written, fixed price so you know exactly what it costs to sort.
Call 07976 730433 or request a visit here.
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