In brief
Yes, a skylight can be fitted in winter. The work is planned around dry spells, and the opening is closed and weathertight before the crew leaves each day. Some sealants, adhesives and roof coverings only cure properly above a minimum temperature set by their makers, so on a cold or wet day we will move the job and keep the roof sound.
- Fitting is booked for dry spells, with the forecast checked before the roof is opened
- The opening is closed and weathertight at the end of every working day
- Sealants, adhesives and membranes each have a minimum temperature specified by the maker
- Wind and rain can stop work on a roof, even when the day is mild
- Ordering early gives the programme room to move a day or two
Why winter is not a bar to fitting
A rooflight job is short compared with most roof work. A roof window in a pitched roof takes only a part of a working day to open up, fit and close, and the roof is back to being a roof by the evening. That makes it easier to choose a suitable window in the weather than for a long job that has to run through whatever the week brings.
Southampton and the surrounding area have wet winters and some hard frosts, but they also have plenty of dry, still days between the fronts. We book the fitting for one of those days and keep the following day free in case the first is lost.
The season therefore changes how we plan, but it does not change whether the work can be done. If you have an old or misted unit that you want replaced before spring, ask for the survey now and the date can be set around the weather.
How the roof is kept dry during the work
On a pitched roof the tiles or slates around the opening are lifted, the rafters are trimmed if the window is new, and the unit is fitted with its flashing kit before the covering is laid back. The opening only exists for as long as it takes to do that, and the new unit goes in before the end of the day.
On a flat roof the unit sits on a kerb, and the timing is led by the roofer. The membrane or covering goes on first, the kerb is dressed up, and the rooflight is fitted onto it. If rain is forecast, we hold the fitting until the covering is complete and dry, since a rooflight fitted onto a wet upstand cannot be sealed correctly.
Inside, a dust sheet and a protective cover under the opening look after the room, and we remove the old unit in a way that keeps debris from falling into it.
Temperature limits on sealants and coverings
Materials do not behave the same in the cold. Sealants and adhesives are made to cure within a stated temperature range, and below it they can fail to bond. Single-ply and bitumen-based membranes can become stiff and hard to dress round a kerb, and some liquid coverings must not be applied when frost is expected or when the surface is damp.
Each maker publishes its own minimum, and that is the limit we work to. The same product stays on the job, because the guarantee on the work rests on it being applied as instructed. If the day is too cold for the product, we move the date.
| Task | Affected by cold or wet | What we do |
|---|---|---|
| Fitting a roof window in tiles or slate | Heavy rain and strong wind | Wait for a dry window and keep the opening short |
| Dressing a membrane round a kerb | Frost, damp surfaces, low temperatures | Follow the maker's minimum and rebook if needed |
| Sealing the rooflight frame | Sealants with a cure temperature | Apply within the stated range only |
| Internal lining and reveals | Little affected | Carry on once the unit is weathertight |
Wind, ice and working safely at height
Weather affects the people on the roof as well as the materials. Strong wind makes it unsafe to carry a large pane, and a lantern or a big flat rooflight in a gust is a hazard to the crew and to anyone below. Frost or ice on slates and scaffold boards can stop work for the morning even when the afternoon is fine.
Short winter days matter, too. A job that would sit comfortably in a summer day may be too long for the light in December, so we plan the order of tasks so that the roof is closed before it is dark, and we split a larger job over two days if that is safer.
These are the reasons we keep a flexible day on either side of the booked fitting. A date that cannot move leaves nobody a choice but to work in poor conditions.
Winter on a build programme
If the rooflight is part of an extension or a loft conversion, winter is where the programme needs most slack. The roofer, the electrician and the plasterer each depend on the one before, and a lost day at the roof moves everyone after it.
We reduce the risk by ordering against the build programme and passing the confirmed delivery date to both homeowner and builder, and by sending the opening sizes in writing, before the deck. A unit that arrives when the opening is ready can be fitted on the first dry day, whereas one that arrives late can lose the whole window. Our note on how long rooflights take to arrive explains how the order date is worked out.
For a flat roof, the choice of who forms the kerb also affects the winter sequence, because a kerb built early lets the roofer cover the deck while the weather allows. See who builds the kerb for how that is agreed.
Booking a winter fitting
Winter fittings are booked in the same way as any other. We survey the roof, send a written quote naming the unit, its glazing and the lead time, and agree a target week. The exact day is set when the forecast is clear, and we tell you the day before whether the weather has changed it.
If you have an older unit, such as a misted double-glazed rooflight that you want replaced, the work follows the same pattern. Our rooflight installation service in Southampton explains how the survey, the order and the fitting fit together, and our guide to Building Regulations for rooflights covers when the work is notifiable.
