The short answer
Small chimney jobs such as rebedding a pot or renewing flaunching often take part of a day. Repointing a stack or renewing flashing usually takes a day or two. A partial or full rebuild takes several days or more, with scaffold time on top. Weather, access and what is found behind the brickwork can all lengthen the job.
Typical times by type of job
These are working estimates for a single, accessible stack, not promises, and your own timetable is fixed only when the quote arrives after the survey. The table shows where each common job tends to sit.
| Job | Typical time on site |
|---|---|
| Rebed a pot, renew flaunching | Part of a day |
| Repoint one stack | One to two days |
| Renew lead flashing and back gutter | One to two days |
| Rebuild the top courses of a stack | Two to four days |
| Full stack rebuild to roof level or below | Several days, sometimes a week or more |
A larger or taller stack takes longer, as does a stack with several pots and flues. Our guide to chimney repair costs shows how the work and the price move together, and the chimney repairs hub links to each job in the table.
Arrival time on the first morning, loading materials and setting up the work area all count towards the day, so a job described as half a day usually means an early start and a finish before mid-afternoon.
Scaffolding adds days at either end
Most stacks above a first floor need scaffolding, and the time it takes to erect and strike is on top of the working time. A scaffold is often up for a week or longer because the scaffolder books around the roofer, and hire is charged by the week. MyBuilder's scaffolding guide, updated 21 August 2026, puts high-level chimney scaffolding at £400 to £900, and Checkatrade's February 2026 guide gives chimney scaffolding as £660 per week.
That is why a short repair on a tall house can still mean a week of scaffold. Our page on chimney scaffolding covers the alternatives, such as a tower or a roof ladder, which can shorten the whole job on lower stacks. Before you accept a quote, check that scaffolding and VAT are covered and how long the scaffold is expected to stay up. A longer hire is the usual reason a quoted price creeps upwards, so it is worth asking early.
Weather and curing
Mortar needs time to set, and it cannot be laid in heavy rain or hard frost. Fresh pointing and flaunching are protected from showers and from rapid drying, and repairs started in a poor forecast often stop and restart. That is normal. A chimney job planned for two days can become four if the weather turns midway, and it is better to wait for a dry spell than to lay mortar that washes out.
Winter is the hardest time. Frost-damaged stacks often need work just when conditions are worst, which is why our guide on chimney winter damage suggests temporary protection first and the permanent repair when the weather allows. High winds also halt work at height. We cannot promise dates against the weather, but we will tell you what the forecast is doing to the plan.
Lime mortar, used on many older stacks, sets more slowly than cement mixes and needs gentler protection while it does, which can add a day of covering and watching the sky.
Cold, damp weather also slows the drying of fresh pointing, so after a spell of rain we often return briefly to check the finish before the scaffold comes down.
What the survey cannot see
Some of what lengthens a job is hidden until the brickwork is opened. Soft or crumbling bricks under old render, a stack whose old lime mortar has washed away inside, a missing flue liner, or timber near the stack that has rotted can all turn a repointing job into a rebuild of the top courses. We photograph what we can see and tell you where the unknowns are, so a change in scope never comes as a surprise.
If a stack shares a wall with the neighbours, timing also depends on them. Access from their side, or a party wall notice, can add weeks before work starts; the issues are set out on our shared chimney stack page. Similarly, if a breast below has been altered, structural checks come first; see chimney breast removed. In both cases the roofing is the last step, not the first.
Where a stack has been rebuilt before, the old work sometimes hides the cause of the fault, so allow for a little extra time while we trace it.
Planning your own week
A few practical points make a repair less disruptive. Move parked cars and garden furniture away from the area below the stack. Tell us about dogs, children, a window cleaner's schedule or a neighbour who needs warning about a scaffold. Make sure we can reach the loft if the survey asked for it. Work above a conservatory or a flat roof may need extra protection, so mention those too.
The roof is left weathertight at the end of each day, the site is cleared and waste is taken away. Waterproofing treatments sometimes follow a repair; our page on chimney waterproofing explains whether you need one and how long the stack should dry before it is applied. Our work carries a 10-year workmanship guarantee in writing, though it is not insurance-backed.
If a stack has several flues, ask whether all of them need work in one visit. Doing the pots, flaunching and pointing together usually saves time, scaffold and disturbance, even if it makes the day longer.