Chimney sweep or roofer: who do you call?

A chimney has an inside and an outside, and each trade owns one of them. A sweep works from the fireplace and the flue. The job is to clear soot and debris so smoke leaves the house, and to see what state the inside of the flue is in. A roofer works from the roof and the loft. The job is to keep rain out of the stack and out of the house around it.

Think of the stack as a small tower standing on the roof. Its brickwork, its pointing, the sloped mortar bed on top that holds the pots in place (called flaunching), the pots themselves and the lead round its base all belong to the roofer. The soot, the flue lining and the opening above the fire belong to the sweep.

Neither trade can stand in for the other. A sweep who finds crumbling brickwork will usually send you to a roofer, and a roofer who finds a blocked flue should send you to a sweep. The clues in the next two sections usually settle which end the trouble starts at.

Water is the giveaway. A brown mark on the chimney breast upstairs, damp on the ceiling beside it, or drips in the loft near the stack all point to the outside. Rain gets in at the flashing (the lead strip running between brick and tile), through cracked flaunching, through open joints in the brickwork, or round a pot that has worked loose. None of that is a flue problem, and sweeping will not stop it.

Other roof-end signs can be seen from the garden: bricks that have lost their face, pointing that has washed out, a stack that leans, a pot sitting crooked, or lead lifted at a corner.

A roofer's job starts with a survey and photographs of each fault. You then learn if a patch will do or the stack needs deeper work. Our page on whether roofers repair chimneys sets out the range of work, and the chimney repairs page covers the rest.

Smoke drifting back into the room, a fire that sulks and will not draw, soot dropping into the grate, or a sooty smell when the weather turns damp: these start inside. So does a flue that has stood unused for a long time and may hold fallen debris. A sweep can clear it and look up the flue to see what is there.

Be wary of the idea that a sweep can cure a leak. From the fireplace they cannot reach the flashings, and sweeping does nothing for a stack that is soaking up rain. The reverse is also true. A roofer can rebuild a stack, but the soot inside it is the sweep's work. If an open fire or stove is in regular use, how often the flue is swept is for you to settle with your sweep and your stove or fuel supplier.

One more point about pots. Birds sometimes nest in them, and a nest being used is protected, so ask before anything is pulled out.

Plenty of chimneys need both, and the order matters. If a roofer is about to change pots, fit cowls or rebuild the top courses, tell the sweep. Work at the top of a stack knocks mortar and brick dust down the flue, so a sweep after the repair leaves it clear, and new cowls change how the flue behaves.

Scaffold is another reason to plan. A stack is a high job, and the access can be the largest single cost. Checkatrade's scaffolding guide (table last updated October 2026) gives around £660 a week for a chimney. If your stack needs inspecting and repairing, do the checking in a single trip, so the access only has to go up once. Our guide to scaffolding for chimney repairs explains the set-up.

If the chimney is coming out altogether, Building Regulations approval always applies to taking out a chimney breast, which holds up part of the structure.

You do not have to diagnose it. Describe what you can see and where: whether water is coming in, where the stain is, whether the fire or stove is in use and whether the flue draws. That is enough for the right person to recognise the job.

Photograph the stack from the ground, the stain inside and, if it is safe, the loft around the chimney breast. Never climb onto the roof or lean a ladder against the stack, because pots and old brickwork can give way.

Send the photographs to us on WhatsApp or through the enquiry form and we will tell you whether it is a roof job, a flue job or both. If a roof is leaking we prioritise it and make it safe first. Our page on a damp chimney breast helps you read the mark.

Whoever you call, ask what they found and ask for it in writing. A decent report names the fault, shows a photograph of it and says what would put it right. Be wary of a vague "your chimney needs doing" with no picture to back it up.

Find out if the price includes VAT and the scaffold, since both can change a total by a good margin. A sensible tradesperson also stops and tells you if extra work turns up, instead of adding it to the bill afterwards.

Our order is photographs first, then one total price in writing.