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Flat roof leaking? What to do next.

A leak is stressful, but the first hour matters more than panicking. Here's how to limit the damage, what to avoid, and how to get it sorted properly.

Water coming through a flat roof is alarming, but a leak rarely means the ceiling is about to come down in the next five minutes. What matters is limiting the damage now and getting the roof looked at quickly, before a small problem soaks into the timber and turns into a big one. Here's the calm, sensible order to do things in.

1. Limit the damage inside

Deal with the inside first, it's where the expensive damage happens.

Don't go up on a wet flat roof yourself A wet flat roof, especially felt or a mossy older surface, is dangerously slippery, and you can do real damage (to the roof and yourself) trying to find a leak in the rain. Leave the roof itself to someone with the right access and footing. If you have an active leak, call us and we can get out to it.

2. Understand why leaks are hard to place

The wet patch on your ceiling is often not directly below the hole. Water gets in at one point, then tracks along joists, boards and battens before it finds somewhere to drip. That's why chasing the stain rarely finds the cause, and why a proper diagnosis means looking at the whole roof, not just the spot above the mark. Common culprits on a flat roof are:

If you want to get a sense of which of these you're dealing with, our guide to the signs a flat roof needs replacing walks through them in more detail.

3. Get a temporary covering if it's bad

If the leak is significant or more rain is coming, the priority is stopping more water getting in while you arrange a proper fix. We can fit a temporary covering quickly to buy you time and protect the inside, then look at the permanent repair once things are dry. Tell us it's an active leak and we'll prioritise it.

4. Repair or replace?

Once the roof's been inspected, the question is whether a repair will hold or whether the roof has had its day. If it's young and the damage is in one spot, a repair is usually the sensible, cheaper answer. If you've patched it before, or the covering is cracked and tired all over, you're likely throwing good money after bad. We cover exactly how to weigh that up in flat roof repair or replace?, and if it does come to a new roof, a seamless GRP fibreglass roof has no joints to leak and lasts 30 to 40 years.

Get it looked at

The sooner a leak is diagnosed, the less it costs to put right, because you catch it before the deck below gets wet. We give a straight assessment and a fixed price, and we'll tell you honestly if a repair is all it needs. If you've got water coming in right now, don't sit on it.

Call 07976 730433 or request a visit here.

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