Rain on a re-roof
What happens if it rains during a roof replacement?
The short answer
If rain arrives during a roof replacement, the crew covers whatever is open and stops work that cannot be done wet. The roof comes off in stages, each one small enough to be sealed again quickly, and temporary sheeting protects the rest. Heavy rain and strong wind can pause the job for a day, which stretches the programme but does not usually harm the house.
How an open roof is protected, which weather stops work and which does not, and what to do if you see water coming in.
How an open roof is kept dry
The fear is a bare roof and a wet bedroom, and the routine is designed to prevent exactly that. The crew works in stages, taking off only the area it can re-cover that day. Once the old tiles or slates and the battens are stripped from a section, a new underlay, the waterproof membrane that sits beneath the covering, goes on, and it is battened down so wind cannot lift it.
Before the crew leaves, anything still open is sheeted over. Tarpaulins or heavy-duty temporary sheets are weighted and strapped down at the ridge, the eaves and the edges. The Institution of Structural Engineers uses the same idea for storm damage, recommending temporary coverings to prevent water ingress.
The method does depend on a forecast being read properly. Before work starts each morning, the lead roofer checks the sky and the forecast and decides how much of the roof to open. If the outlook looks unreliable, less is opened, and the sheeting is kept close to hand.
Which weather stops work
Light, passing rain is usually fine on a pitched roof once the underlay is on, and the crew can carry on tiling. Heavy or driving rain is another matter. It makes the slopes slippery, hides what you are doing and can push water sideways under a loose sheet, so work pauses and the exposed area is covered.
Wind is the bigger obstacle than rain. A gust can catch a full-size sheet of membrane or a pallet of tiles and turn it into a hazard, so on a blowy day the crew may stop lifting materials even when it is dry. On a coastal stretch like ours, gales and driving rain come with the territory, so the programme allows for lost days instead of pretending they will not happen.
Flat roofs are fussier. A covering such as felt, EPDM or GRP is laid onto a dry deck, so a flat roof that is damp from a shower stays uncovered until it has dried out.
If water does get into the house
Tell the crew straight away, whether it is a drip in the loft or a stain on a ceiling. Do not wait for the end of the day. Someone can go up and find the opening, which is often a loose corner of sheeting or a gap at a chimney or valley, and fix it while the weather is still on the move.
Protect what you can in the meantime. Move furniture and bedding away, put a bowl or bucket under the drip, and lift rugs or electrical items off a wet floor. If a ceiling is sagging or bulging, keep people out from underneath it and tell the crew at once.
Take dated photographs of the water and the damage. They show what happened and when, and you will want them if the question of who pays for repairs ever arises. The written quote should be clear about who is responsible if the roof lets rain in while it is open, so ask before you accept it.
What the quote and programme should say
Weather is the one thing in a roof job nobody controls, so the paperwork should deal with it plainly. Ask how the crew decides which areas to open, who covers the cost of temporary sheeting, and how a delay is handled. The written quote is a total price, so a day lost to a gale should not lead to a surprise charge, and you are entitled to have that confirmed in writing before you sign.
Our survey includes the roof shape and the exposure of each slope, because a sheltered rear slope can be stripped in conditions that would be a poor idea on an open front one. We tell you at the survey which parts of your roof are the awkward ones.
You can read more about the whole sequence in our guide on what happens during a roof replacement, day by day, and about the colder months in replacing a roof in winter.
Choosing a better moment
You cannot pick the weather, but you can improve the odds. A long dry spell is rare, so aim for a booking window rather than a single date, and be ready to move within it. Firms that insist on starting on a fixed day whatever the forecast are the ones most likely to leave a roof open to bad weather.
If the roof is already leaking, waiting for perfect weather may do more harm than starting. In that case a temporary make-safe can hold things while the right days are found, because a leak gets our attention ahead of routine work. Tell us about it when you book, and describe where the water is coming in, so the first visit can be planned around it.
The time the work takes overall is covered in how long a roof replacement takes. The full range of work is on our roof replacement and new roofs page.
Related questions
Wet weather queries
Is a forecast of showers enough to postpone a re-roof?
Usually not. Showers can be managed by opening smaller sections and sheeting up early. A forecast of heavy rain or strong wind across the day is a different case, and the crew will hold off or stop and cover up.
Who pays if rain damages my ceiling during the job?
That should be settled before work starts. Ask in writing who is responsible if the roof lets rain in while it is open, and photograph any damage straight away so there is a dated record.