What happens if it rains during a re-roof?

The main protection against rain is planning. A roofer strips a section that can be weathered the same day, not the whole house at once. A slope is taken off in bays, with underlay and battens following close behind and the new covering laid as far as the light and the forecast allow.

When the crew packs up, anything uncovered is protected. If the forecast is poor, the crew strips less, or leaves the old covering on until conditions improve. Starting a strip and then leaving a roof open on a wet night is the avoidable error.

Checking the forecast is part of the morning routine, and more than one source is worth reading. Forecasts can change fast, so if a front moves in earlier than expected, the crew covers the open section first and finishes the rest later. That sequence, cover first and carry on after, is the habit that keeps a wet room from becoming a claim.

Early starts help. Getting the strip done in the morning leaves the afternoon for underlay, battens and covering, so more of the slope is closed in before the light fades.

Where a slope is open, it is covered with heavy tarpaulin or roofing sheeting. It runs from above the ridge down past the eaves, so water falls clear of the open area, and it is fixed to battens or the scaffold, not simply weighted with a few tiles. Wind gets under a loose sheet quickly, so edges are secured on all sides and the sheet is checked before the crew leaves.

New breathable underlay and battens add protection once they are on, though underlay is a secondary layer and not a final covering. It is laid with laps and fixed to shed water, and is not left exposed for weeks. Our page on battens and underlay in a re-roof says more about it.

Chimneys, valleys and the junction with a neighbouring roof are the weak spots during a strip, so they are covered carefully, and lead flashings are replaced as soon as possible.

Overnight, sheets are checked for flapping and lifted corners, because a sheet that drums in the wind is also letting air and water underneath it.

If rain starts during the work, the first job is to cover the open area, then to move to a dry task where possible, such as sorting materials or working on lead, guttering or the other slope. Our notes on fascias and gutters in a re-roof show which of those jobs can carry on in a shower.

Roofers do not work on wet slate or tile in a storm. A damp surface is slippery and wind on a scaffold platform is a danger, so the crew stops and waits it out. That affects the programme, which is why our answer on how long a re-roof takes allows spare days, and why the choice of season is worth thinking about.

Wet weather also affects some materials. Mortar and sealants need to cure, and lead needs to be dry for proper dressing. Those jobs are held back until conditions allow, even if it means a return visit.

After a wet spell, the foreman checks sheets and underlay before the crew starts again, because standing water on sheeting can add weight and tear fixings.

Most leaks during a re-roof are small. A sheet edge lifts, a rafter gap lets a trickle through, or condensation drips from cold timber. Tell the foreman at once, and put a bowl or bucket under the drip. Move furniture and electrical items out of the way, and keep away from ceilings that look swollen or stained.

If a light fitting is wet, switch off that circuit at the board and do not use the light until it has been checked. Ceiling plaster can hold a lot of water before it fails, so a bulging patch is best left for the roofer or an electrician to deal with rather than poked from underneath.

We make the roof safe first, then look at damage. Take dated photographs of anything affected and keep them. Your buildings insurance may respond to storm damage, and we cannot say what yours covers, so ask your insurer if there is a loss.

Ceilings below a stripped roof are the most likely to show a stain, and old stains can reappear in wet spells. Mark any existing ones with a pencil before the work, so you can tell old from new.

Ask what the plan is for each day, how much of the roof will be open at once, and what the crew will do if the forecast turns. Ask where the sheeting is stored and whether spare is kept on site. A roofer who can answer clearly has thought it through.

At survey we photograph your roof and note chimneys, valleys, dormers and tricky access, because those decide how a roof is covered mid-job. The quote that follows covers each stage, and a ten-year workmanship guarantee in writing covers the finished work. You can read the whole process on roof replacement in Stroud, or ring 01453 933613.

A good crew treats the forecast as a working tool, not an excuse. Ask to see how they plan around it before you agree a start date.