When people ask how long a flat roof takes, they are usually really asking two things: how many days will there be someone on my roof, and how much will it disrupt the house? The honest answer for a typical domestic job, a garage, an extension or a dormer, is two to four days. Here's how that breaks down, and what can push it either way.
A typical job, day by day
- Day one: strip off. The old felt, asphalt or rubber comes off, along with any rotten timber, and it all goes in the skip. We check the deck underneath at this point, which is when any hidden problems show up.
- Day one or two: the deck. A new 18mm OSB3 deck goes down where it's needed, along with the trims and edging that shape where the water runs off. Getting the falls right here is what stops ponding later.
- Day two or three: laying the fibreglass. The resin and matting are laid out wet and consolidated by hand into one continuous sheet. This is the part that needs dry conditions.
- Day three or four: topcoat and finish. The coloured topcoat goes on, edges and details are finished, and the site gets cleared and swept.
A small porch or bay roof can genuinely be a one or two day job. A large or complicated roof runs longer.
What makes it take longer
- Size. The obvious one, though it isn't linear, a roof twice the size rarely takes twice as long.
- Access. A ground-floor garage is quick. Anything needing scaffolding adds time before and after the roofing itself.
- The deck underneath. If we strip off and find rotten or sagging timber, replacing it adds time. It's also the most common reason a job runs a day over.
- Complexity. Rooflights, pipes, vents, upstands, changes of level and lots of edges all need detailing properly, and detailing is slow work.
- Weather. The resin needs dry conditions to cure, so persistent rain pauses the job. More on that in the best time of year to replace a flat roof.
An overlay is usually the quickest option of all, because there's no strip-out. If your existing roof structure is sound, we can often go straight over the top and save a day or more.
How much disruption?
Less than most people expect. You don't need to move out, and in almost every case you keep normal use of the house throughout. Practically:
- There'll be a skip or a tidy pile of waste for a day or two.
- It's noisy during the strip-off, less so afterwards.
- We'll need access to the garden or side passage, and somewhere to park a van.
- If the roof is over a room you use, expect some noise overhead, but no dust or mess inside.
- We sheet up, clear as we go, and sweep the site before we leave.
Getting a date
When we come out to quote we'll tell you how many days your specific roof needs and when we can start, rather than leaving you guessing. Summer books up quickly because the weather suits the work, so it's worth getting in early. Have a look at how we build a GRP roof if you want the detail on what's actually going down.
Free, fixed-price quote, no pressure. Call 07976 730433 or request one here.
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