What the Manston averages tell you
Long-term weather figures for this part of Kent are published for the Met Office station at Manston, using the 1991 to 2020 period. They are averages for the whole year, not winter-only numbers, but they show what the weather is like across a roofing calendar.
| Measure | Average |
|---|---|
| Days of air frost | 21.43 a year |
| Days with 1 mm or more of rain | 110.05 a year |
| Rainfall | about 613 mm a year |
| Mean wind speed at 10 m | 9.86 knots (January 11.21) |
Read plainly, there are about 110 days a year when at least 1 mm of rain falls, so any roof left open has to be sheeted or closed in before the crew leaves each evening. Manston also records 21.43 days of air frost a year, so frost is part of the calendar and not a surprise. Manston's January mean wind is higher than its yearly one, at 11.21 knots, which matters for loose sheets and for materials lifted to height.
None of this stops a roofer working. It means that the plan for each day has to check the forecast, and that some jobs are better held until a settled spell.
Jobs that suit the cold, wet months
Work that does not depend on glue or mortar setting, and that can be finished and made watertight within the day, goes ahead in winter without much trouble. The usual examples:
- Making safe after a storm, such as sheeting a damaged slope or fixing back loose tiles.
- Replacing slipped or cracked tiles and slates one by one.
- Clearing and re-fixing gutters, downpipes and outlets.
- Inspecting the roof and the loft, finding where water is getting in.
- Work inside the loft, such as checking timbers and ventilation.
Water that keeps getting into a loft keeps wetting the timbers, the insulation and the ceiling below, so the sooner the entry point is closed the less there is to dry out afterwards.
The sensible approach is to make the roof safe now, and treat the permanent repair as a second step. A temporary repair that keeps weather out is a perfectly good response to a wet week, and the temporary roof repair page explains what one involves. The permanent repair can then be planned for a dry spell, with the leak under control in the meantime.
Jobs that wait for dry, frost-free days
Some work depends on the surface being dry and the air being above freezing. Anything that is bedded, bonded or cured on the roof is in this group. The limit for each product is set by its maker, so the product data sheet is what to check, and the roofer should be able to tell you what it says.
As a rule, these jobs do better when they wait:
- Flat roof coverings that are bonded or cured, where a damp or frosty deck spoils the bond.
- Bedding or pointing with mortar, which needs to cure and can be harmed by frost.
- Coating and sealing work on roofs and flashings, where wet surfaces get in the way.
- Large re-roofs, where a stripped slope has to stay dry until covered.
The page on laying a flat roof in cold weather covers that case in detail, and tiled roof repairs in winter covers the pitched equivalent.
If you are told a job must wait, ask which part of it depends on the weather and what will be done meanwhile. A clear answer sounds like "the membrane needs a dry deck; the temporary cover goes on now". A vague answer is not enough.
How to plan a winter job
If you have a choice of date, the best time for a large job is a run of settled weather. If you do not, a winter start can still work with a plan.
- Ask for a written start date and what happens if the weather stops work.
- Ask how the roof will be closed in each evening during a re-roof.
- Agree who calls it when the forecast is poor, and how you will be told.
- Ask how new tiles and slates will be held on: under BS 5534 the fixing method is calculated for how exposed your site is.
A quote for winter work should say how delays are handled, and the stages should be written down so you know what is done at each point. The page on replacing a roof in winter covers the bigger jobs, and preparing your home for roof work covers what you need to move or clear.
A survey comes before any price, and you are shown photographs of your own slopes. Castle Roofing Margate then writes one total price, and the plan for the weather is in the same paperwork.
