Flat roof storm damage
Flat roof lifted or torn in a storm: what next?
The short answer
Keep off the roof, photograph the damage from the ground or a window, and stop water getting in from inside. A flat roof lifted or torn in a gale needs a roofer to look at the covering, the edges and the deck underneath. A localised tear can often be repaired, but a covering that has peeled back widely, or a deck that is wet through, usually points to replacement.
How to read the damage on a lifted or torn flat roof, what a repair can fix and when starting again with a fresh covering is the sounder answer.
First steps when the covering has lifted
A flat roof that has lifted in a gale often looks worse than it is, with a flap of felt or membrane waving in the wind. Do not climb up to hold it down. The roof may be wet, the deck underneath could be weak and the edge has no fall protection. Photograph it from the ground, a window or a neighbour's upstairs, and warn people off the ground below.
Inside, deal with water as it arrives. Place buckets, move belongings out of the way and check the ceiling for sagging, which means water is trapped above it and may come down at once. Where a light fitting is wet, switch that circuit off at the fuse board only if the floor between you and it is dry. Then ring a roofer. A leaking flat roof is prioritised, and the opening visit aims to get a temporary cover over the damage so more rain stays out. Our page on making a roof safe explains this stage.
Why flat roofs lift in the wind
Wind does not just push on a roof, it also pulls. A gust moving over a flat roof creates suction, and any weak point in the covering, such as an edge, a joint or a poorly stuck patch, gives it something to grip. Once the wind gets under a flap, it can peel the covering back in sheets. The edges and corners are the most vulnerable, because the suction there is strongest. That is why the neat finishing of edges and trims matters so much on this coast.
Age plays a part. A covering that has come unstuck from the deck, or has blistered and cracked in the sun, will fail in the first big gust. Old fixings can also pull out of a weak deck. If the damage is limited to one corner or one seam, the rest of the roof may be sound. If it has peeled across a wide area, the covering was probably near the end of its life already, and the storm just finished it off.
Repair or replace: how the roofer decides
The decision rests on three things: how much covering has gone, what condition the deck is in, and how old the rest of the roof is. A local tear on an otherwise sound covering can be cut out, patched and sealed, with the new piece lapped and stuck down properly. Lifted edges can be re-fixed and the trims replaced. Where that will hold, it is the right answer, and it keeps the bill down.
If the deck is wet, soft or rotten, patching over it only hides the problem, and the whole area needs opening up. Where the covering has failed widely, or has been patched many times, a new roof gives a better result than another repair, and the survey photographs show which case you have. A new flat roof should be laid to a proper fall: BS 6229:2025 keeps a minimum finished fall of 1:80 for general roof areas, yet most roofers aim for roughly 1:40 in the design, so water drains. Our storm damaged roof page covers the wider survey.
What drives the cost
Typical UK guides give a feel for the scale. Less quotes £150 to £500 for flat roof small repairs (last updated March 2026), while Checkatrade shows a flat roof replacement at £2,800 to £7,500, in a table headed plus VAT and updated October 2026. Neither is our price, and your own figure depends on the roof.
Access, the size of the area, the type of covering, the state of the deck and whether scaffold is needed all push the total up or down. Patching a garage roof is nothing like relaying an extension roof that has wet insulation beneath it. The price is written down after the survey as one total, alongside photographs of each fault. When you compare any figures, ask whether VAT and scaffolding are in them. Our guide to emergency roof repair cost goes through the factors.
Wear and tear, storm damage and the paperwork
A policy may treat a roof that was already worn differently from one hit by a storm, and Which? lists a leak through a poorly kept roof under wear and tear. Photographs of the covering before the storm, if you have any, can help, and so can pictures of the underside and the deck once the covering is lifted. Ask the roofer to take them, and to label which picture shows which part of the roof.
We cannot say how an insurer will see your case. What a roofer can supply is a clear written account of what failed, with dated pictures, and receipts for the temporary work. Our answer on storm damage versus wear and tear explains the distinction in more detail. For the full service, see emergency roof repairs, which covers the route from the first call to a roof that sheds water again.
Related questions
Flat roof storm questions
Can I weigh the flap down with bricks?
That means going onto the roof, which we advise against. Loose weights can also slide off the edge and hurt someone below. A roofer can secure the flap or lay a temporary cover safely, and will check the deck at the same time.
Will the whole roof need replacing?
Not necessarily. A local tear on a sound covering can often be repaired. A widely peeled covering, or a deck that is wet or soft, usually points to replacement. The survey photographs show which applies, and the verdict is the smaller job whenever the smaller job will hold.