How Long Does It Take to Replace a Skylight?

Most skylight replacement time comes down to one question: is the new unit going into the same hole as the old one, or a bigger one? A like for like swap answers that in the simplest way possible, and the day runs in one continuous sequence rather than in stages spread over a week.

We arrive early, sheet the floor and any furniture below the opening, and set up access, whether that is a roof ladder or a small platform. The old unit comes out, the kerb or frame is checked, and the new glass goes in on the same fixings points where the roof already knows how to take it. Flashing is dressed back in, the felt or membrane is lapped correctly, and the room is weathertight again within a few hours of the old glass coming out. Can a skylight be replaced without redoing the whole roof? covers what does and does not get disturbed around it.

The inside finish usually happens the same afternoon: the reveal is made good, one coat of filler or plaster goes on, and the room is left tidy with the second coat and painting left for you, once it has dried. A full account of the sequence, start to finish, is on What Happens on Rooflight Installation Day.

Once the opening itself changes size, the job stops being a swap and becomes a small structural alteration, and the timeline changes shape with it.

Trimming rafters or joists to widen an opening, adding new trimmers to carry the load either side, and dressing new flashing to a bigger kerb all take longer than reusing what is already there. Upsizing a Rooflight Opening: What Is Involved goes through what the roof structure needs when the glass gets bigger, and it is worth reading before you settle on a size.

Plaster is the other reason a bigger job runs long. A skim coat over new lining board wants a day to go off before a second coat can follow, so an enlarged reveal often means the plasterer returns the next morning rather than finishing in one visit. Making Good Inside After a Rooflight Is Replaced sets out what is disturbed and what is left ready to decorate.

How we get up to the opening changes the shape of the day as much as the opening itself does. A single pitched roof window within reach of a roof ladder needs very little set-up time. A rooflight high on a hip, on a flat roof over a single-storey extension, or above a stairwell with no safe standing space nearby, usually needs a tower or scaffold put up before any work on the glass can start.

Do You Need Scaffolding to Fit a Skylight? explains when that applies. Where it does, add a morning for the scaffold to go up and another for it to come down, on either side of the fitting itself. A job with awkward access is not necessarily harder work, but it is a longer one, because the people and the platform have to be in place before the roof can be opened at all.

Glass and roofing work stop for rain, not for cold. A dry, calm day in January goes just as well as one in June; a wet or gusty one in either month means the opening stays sheeted and covered until conditions allow the roof to be cut safely. What Time of Year Is Best to Install a Skylight? looks at this across the whole year.

Where a replacement is notifiable, the Building Control side runs in parallel with the physical work rather than in front of it. The notification is submitted, the work goes ahead, and sign off follows once the finished job has been checked against current Building Regulations. Does Replacing a Skylight Need Building Control? sets out when that step applies and when it does not.

That means the paperwork rarely adds days to the fitting itself. It does mean the certificate lands a little after the last coat of paint, once everything has been reviewed, which is worth knowing if you need proof of compliance for a sale or a mortgage lender soon after the work.

Dust and debris are the part people ask about most, and they are manageable rather than something to dread. Floors are sheeted, the opening is worked from above wherever the roof allows it, and what does come down inside is swept and vacuumed before we leave. Will Fitting a Rooflight Make a Mess Inside? covers exactly what to expect and what to move out of the room beforehand.

You do not need to clear the whole house, only the room below the opening and a sensible path to it. A bedroom stays usable that night once the glass is in and weathered, even if the plaster is still curing on the walls of the reveal. A kitchen or bathroom with pipework or wiring near the opening can take longer to make safe, simply because there is more below the ceiling to protect.

Every quote we give starts with a sightline sketch, the drawing of the view you will get from the bed, the sofa or the sink, and that same visit is when we walk through how many days your particular job will take and what access it needs. You can see the full range of what we fit and replace on our skylight and rooflight installation pages, and what the size and type of unit does to the overall cost on What Affects the Cost of a Rooflight.

Do you need to be home for the whole job?

Someone needs to be able to let us in and out and to say where furniture can be moved, but you do not have to stand over the work all day. Normal life carries on in the rest of the house while the roof is open above one room.

How soon can the room be used again?

Once the glass is fitted and weathered, usually the same day on a like for like job, the room is dry and safe to use straight away. The reveal will still be drying out for a week or two before it takes paint well, but that does not stop the room being lived in.

Does fitting a second rooflight in the same roof add a full extra day?

Not usually. Setting up access and protecting the room happens once for the visit, so a second unit close by in the same roof slope is often finished in a few extra hours rather than a whole additional day.

Can bad weather part way through a job leave the roof open overnight?

No. The opening is sheeted and secured before we leave, whatever stage the job has reached, so a shower overnight or a delay to the next visit does not put the room at risk.