Snow and ice damage on roofs: what to check

A layer of snow is heavy, and it sits unevenly. It drifts against chimneys and dormer cheeks, builds up in valleys (the internal gutters where two slopes meet) and piles on flat roofs that cannot shed it. Most pitched roofs carry the weight without trouble, but older timbers that were already tired can show their age.

The sharper problem is water. Heat leaking through the ceiling warms the underside of the covering, melts the snow above it, and the meltwater runs down to the eaves, where the roof edge is cold and the water freezes again. A ridge of ice builds along the gutter line. Behind it, later meltwater has nowhere to go, so it creeps back up beneath the laps of the tiles or slates, past the underlay and into the loft. This is why a house can leak in a thaw even though the roof was dry in a downpour.

Frozen water also expands inside porous tiles and cracked slates, and flakes their faces. That damage is slow, so a roof can look fine the week after the snow and fail the following winter.

Wait until the thaw is finished, then walk round the house in daylight. Look first at the gutters and downpipes: sagging runs, a joint that has pulled apart, a bracket hanging loose or a pipe split along its length are all typical after ice. Pieces of tile or stone on the ground and in the flower beds tell you something has come off.

Then look up at the slopes, ideally with binoculars. You want gaps in the pattern of the tiles, one slate hanging below the rest, a crooked ridge, and cracked or lifted hip and verge tiles. Check the lead flashings around chimneys, because heavy snow can pull a loose flashing out of the mortar joint. Look at the chimney itself for open joints.

Do not climb up to check. A thawing roof is slippery, and loose tiles can slide. Photograph what you find and note which slope it is on. Our note on what to tell a roofer about a leak lists the details that help most.

With a torch, check the roof timbers near the eaves first, since that is where ice dams do their work. You are looking for dark, damp patches on the timber, water stains on the underlay, drips on the insulation, or a faint line of daylight between slates and tiles. Check around the chimney breast, pipes and roof windows.

Touch the insulation. Damp, flattened or discoloured insulation suggests a longer-running leak, and it will need to dry or be replaced once the roof is sound; our answer on wet loft insulation after a leak covers that decision.

Condensation can mimic a leak after a cold spell. Frost forms on cold nails and the underside of the covering, then melts and drips. If the dampness is a scatter of tiny droplets on nail points, with no stain tracking down from one place, ventilation is the likelier issue, not a hole in the roof.

Snow often leaves a pitched roof in one go, and it can take tiles, solar panel fittings, guttering and satellite equipment with it. Under a heavy slide, a run of tiles may be pushed down the slope, leaving a gap in the covering and a loose tile still resting on the next course. Those are the pieces that fall in the next gust.

Look at the ground beneath the eaves before letting children or pets out, and keep people clear of the line below a damaged slope. If a tile is hanging, do not try to knock it off from below. A roofer working with proper access can remove or secure it, and secure the roof.

Slipped tiles sometimes trace back to the fixings, not the snow: old nails rust through, clips lose their grip and pegs on stone roofs can rot. The snow only revealed what was already weak. That is one reason we look at the whole slope and not just the gap. If the damage looks like it follows a storm, the page on roof repairs sets out how we approach it.

After snow, the tempting fix is a tub of sealant or a spray-on coating over the obvious crack. On a pitched roof it rarely holds, because the movement of cold and warm weather opens the bond. Our answer on roof sealants and spray-on fixes explains where a sealant is a stop-gap and where it hides the real fault.

If water is coming in now, the sensible response is a temporary cover fitted safely from proper access, then the repair in drier conditions. Fitting a tarpaulin is not a job to do from a ladder in icy conditions.

Insurance may be relevant where snow or ice has caused sudden damage. Keep dated photographs and ask your insurer what the policy covers before arranging repairs.

Call if you see missing or displaced tiles, a lifted flashing, a gutter that has come away, or any damp in the loft or ceiling. A small amount of cracked guttering can wait a few days for a dry spell. Water entering the house cannot.

On a survey we check the covering, the ridge, hips and verges, the lead, the gutters and the loft timbers, with photographs you can look at yourself. Typical UK costs vary with the damage: MyBuilder's 2026 guide puts minor repairs at about £100 to £300 and storm-damage fixes at about £500 to £1,500. Those are national figures. Once we have surveyed, the quote we send covers the whole job.

Winter timing and wet-weather working are covered separately in our note on roof repairs in winter. The number is 01453 933613, and WhatsApp and the enquiry form are open too.