How Long Does Chimney Repointing Take?

What fills the time

Repointing sounds like a small job, and in the sense of the brickwork it is. The hours go into doing it properly. The old, failed mortar has to be raked out of every joint to a depth of roughly twice the joint width, so the new mortar has enough grip. The joints are brushed and dampened, and then filled with fresh mortar in layers, pressed in firmly, and finished to match the original profile. Doing this on all four faces of a stack, at the top of a ladder or platform, is slow work.

It is also work that can be done well or badly depending on how much time it is given. Rushing the raking leaves shallow joints that fall out again within a few winters. Good pointing is as much about preparation as the finish, and the clock on site reflects that. Our guide to chimney repointing explains the method step by step.

A typical timeline for one stack

1. Survey and quote, usually on a separate visit, with photographs of the stack so you can see what needs doing.
2. Scaffold or access platform put up, often the day before or first thing on the day, depending on the house.
3. Raking out and brushing down: about half a day for an average stack with sound bricks.
4. Repointing in layers: the rest of the first day, and often some of the second.
5. Checks, flaunching or pot work if included, and clearing up: part of the final day.
6. Scaffold taken down, usually a day or so after the roofing work finishes.

On a plain two-storey semi with a single stack, many repointing jobs fit inside that outline. A larger stack, or one that carries several pots, takes longer. We tell you the likely number of days in the quote, and we explain what could change it.

What makes a job run longer

Several things stretch the schedule. Height and exposure slow the work, because every task is harder in wind and the crew takes more care. Brick condition matters: if bricks are spalled or loose and need replacing or rebuilding, the job moves from repointing to part rebuilding, which takes more days, and our page on chimney rebuild or repair covers that decision. Lime mortar sets more slowly than cement mortar, and needs protection while it does so. Weather is the other big factor. Rain washes fresh mortar out, and frost can ruin it, so a day lost to weather is common between October and March. The page on repairs in winter explains how we plan around it.

Extras also add time. Replacing the flaunching, rebedding the pots, renewing the lead flashings or fitting a cowl all happen at the same visit, and each adds a few hours. It is usually more efficient to do them while the access is up.

How long until the mortar is hard

Fresh mortar is firm enough to shed rain within a day or so, but it continues to harden for much longer. Cement-based mortar gains most of its strength within a couple of weeks. Lime mortar takes longer, because it sets partly by taking in carbon dioxide from the air, and it can go on firming for weeks or months. Meanwhile, it needs protecting from heavy rain, hard frost and fast drying in strong sun. We cover work with hessian or sheeting where the weather is poor, and dampen the joints in hot weather if they dry too quickly. You do not need to do anything, but you should not be alarmed if the new joints look a little darker when damp or lighter when dry.

Which mortar suits your stack is a separate question. Our page on lime or cement mortar for chimneys covers it.

Planning around the days on site

Tell the crew about anything that affects access: a narrow side path, a parked car that needs moving, a dog in the garden, a neighbour's boundary that scaffold may need to cross. Tell us too if the loft will be needed, for instance to check the underside of the stack where it passes through the roof. Small points like these save an hour here and there, and they keep the programme from slipping. Because the days run in sequence, a late start on the first morning moves everything after it, so we agree the start time with you beforehand.

Cost and what to expect from the quote

Time on site is only part of the bill. Published UK guides give repointing a chimney as £450 to £1,200, with about £750 named as a typical job. Access can add substantially, as roofline scaffold hire is quoted at £200 to £2,600 in one guide, so the size of the house and the position of the stack matter. Your fixed quote follows the survey, and it lists the access, the repointing and any extras separately, with the days we expect the work to take. At the end, the site is left clear and the waste is gone. For related work, return to chimney repairs in Basingstoke.