Does Hail Damage UK Roofs?

What hail does to a roof

Hail is ice falling at speed, and the damage depends on the size of the stones, the wind driving them and what they land on. Pea-sized hail in a short shower does little to a modern tiled roof. Larger stones, the size of marbles or bigger, carry enough energy to crack or chip tiles, especially ones that are already weak with age, frost damage or surface wear. In the UK, hailstorms are usually local and brief, but a single bad one can mark every roof along a street while the next road is untouched.

The materials most at risk

Some roof coverings suffer more than others.

• Old slates and clay tiles. Age makes them brittle. Hail can crack a slate across its width or chip the lower edge of a plain tile.
• Rooflights and polycarbonate. Thin plastic sheets and acrylic domes can crack or craze. Garden room, conservatory and porch roofs are the usual victims.
• Felt flat roofs. Hail can bruise the surface, knocking mineral chippings off and cracking the bitumen layer underneath, which may only show as a leak later.
• GRP and EPDM. Both stand up better, but a hard impact can crack a GRP topcoat, and sharp stones can scuff the surface of rubber membranes.
• Soft metals and gutters. Lead, zinc and aluminium dent. Plastic gutters can crack in cold weather.

Conservatory roofs get a section of their own in our guide to how long polycarbonate roofs last, because age and sunlight make hail damage more likely.

How to check from the ground

Do not climb up. Walk round the house and look at what has landed. Cracked fragments of tile or slate in the garden are a sign. Look at the roof through binoculars from a safe spot for broken, chipped or displaced tiles, and dark patches where granules have been knocked off a felt roof. Check the gutters and downpipes for dents and cracks, and glance at the cars, sheds, greenhouses and fences, which show how heavy the hail was. Inside, check the ceilings and the loft for fresh stains over the next few days of rain, since small cracks only leak when it rains.

Hidden problems

Hail damage can be quiet. A tile may be cracked but still sit in place until the next frost splits it. A felt flat roof may have micro-cracks that open in winter. Skylights can have damaged seals. A survey that includes close-up photos of the slope is the best way to find these. Our guide to storm damage to roofs sets out what we look for after bad weather.

Hail, wind and what else comes with it

Hail rarely arrives alone. The same storm cell often brings gusts that lift tiles and flashings, and heavy rain that finds every new crack within minutes. If a hailstorm has passed, expect to find wind damage as well, and look for lifted ridge tiles, bent flashings and slipped tiles alongside the cracks. Our page on what wind speed damages a roof covers that side. After a storm, check the loft the next time it rains for dripping or darker patches on the felt and rafters.

Gutters often show hail first, and so do soft surfaces such as garden furniture covers and the top of the shed roof. A gutter full of ice and a scatter of cracked plastic fragments tells you how hard the storm hit. Write down what you see on the day, because memories blur, and a note with a time helps both a roofer and an insurer.

Insurance and evidence

Hail counts as storm damage on most buildings policies, but wear and tear is excluded, and an insurer will want to know whether the damage was caused by the storm or by age. Photograph everything with dates, keep any broken pieces, and note the date and time of the storm. A written report from a roofer helps separate hail from old cracks. See what evidence your insurer needs after roof damage for a checklist.

What repair looks like

Repairs range from swapping a handful of cracked tiles to replacing a section of covering. A felt roof with bruising may be patched or, if it is widespread, recovered. Broken rooflights are replaced. Where the weather is still bad and there is an opening, a temporary cover goes on first, as we explain in temporary roof repairs and tarpaulins. We survey, photograph the damage and write a fixed price. If the roof still has years of life, we repair it and say so. The rest of our repair work is listed under emergency and general roof repairs.