Why Chimneys Are The Most Common Source Of Roof Leaks
On a typical Leicestershire roof, the chimney stack is the single weakest point. It pokes up above the line of the tiles, gets the full force of wind and driving rain on every face, and relies on a series of separate weatherings — lead flashings around the base, mortar pointing between bricks, a flaunching cap holding the pots in — that all have to stay sound to keep the rain out.
When any one of those starts to fail, water finds its way down the inside of the stack, into the loft, and eventually onto your bedroom ceiling. Most homeowners only become aware of a chimney problem when the damp shows on a ceiling, by which point the underlying defect has often been quietly progressing for several years.
Most chimney work we do across Leicester falls into one of four categories: failed pointing on the brickwork itself, cracked or missing flaunching at the top, lead flashings that have lifted or split where they meet the roof, or stacks that have actually started to lean and need taking down and rebuilding from a sound course.
What's Involved In A Proper Chimney Repair
We start by getting up to the chimney and assessing it properly — not from the ground with a pair of binoculars. That means scaffolding for any job above bungalow height, because working on a chimney with a ladder leaning against it is dangerous and we won't do it. Once we can stand at the stack and inspect every face, we can give you an honest assessment of what's actually wrong.
Repointing involves raking out failed mortar to a depth of around 15-20mm and refilling with the right mix — lime mortar on older Victorian and Edwardian stacks, NHL or sand-and-cement on more recent brickwork. Using the wrong mortar (cement on a soft Victorian brick, for example) does more damage than leaving it alone, because it traps moisture in the brick and accelerates frost damage. We match the mortar to the building, every time.
Lead flashing replacement uses code 4 or code 5 rolled lead to BS EN 12588, with proper soakers between every course of slates or tiles, and a stepped or apron flashing dressed over and into a chase cut into the brickwork. Cement fillets across the brickwork — which you'll often see on cheap repair jobs — are not weatherproof and we never use them as a substitute for proper lead.
Chimney Removal & Capping
If the chimney is no longer used — if you've changed to a combi boiler, blocked off the fireplace, or simply don't burn anything any more — you have two options. The cheaper option is to cap it: take the pots off, fit a vented chimney cap that lets the flue breathe but stops rain getting in, and re-flaunch the top so it sheds water properly. This keeps the visual appearance of the chimney intact, which matters in conservation areas and for kerb appeal generally.
The more involved option is to remove the chimney entirely. This means dropping the stack down to roof level (or below, into the loft), then tying in new rafters, fitting matching tiles or slates over the gap, and dressing in new flashings if part of it remains. We always recommend keeping at least the part of the chimney that's below the roof line for that reason — full ground-up removal is rarely cost-effective and you lose the option to reinstate later.
Timescales & What To Expect
A simple repointing on one stack is usually a 2-3 day job once scaffolding is up. A full rebuild from a sound course typically runs 3-5 days. Lead flashing replacement on its own is 1-2 days. Capping a redundant chimney is half a day to a day. Full removal is usually a week including the tie-in and tiling work. All of these timescales include the day or two for scaffolding to go up and come back down, which is the bit most homeowners forget about when planning the work.
Frequently Asked Questions
How can I tell if my chimney needs repair?
Look for: dark damp patches on bedroom ceilings around the chimney breast, daylight visible around the stack from inside the loft, broken or missing pointing visible from the ground, leaning or bowing of the stack, and crumbling brick or stone faces. Inside the loft, look for water staining on the chimney brickwork.
Can you do chimney work without scaffolding?
On a single-storey extension we can sometimes work safely from a tower scaffold or roof ladder. On a two-storey house or anything taller we always use proper scaffolding. Doing chimney work from a leaning ladder is unsafe and the finished work suffers because there's nowhere to rest tools or materials.
What's the difference between repointing and rebuilding?
Repointing replaces the mortar between the bricks while leaving the bricks themselves in place. Rebuilding takes the stack down to a sound course (usually a few courses below the roof line) and lays it back up with new mortar and either the original bricks if they're salvageable or matching new ones.
Do I need scaffolding to repair my chimney?
Yes, in nearly all cases above single storey. Scaffolding cost is included in our quote — it isn't an extra.
How much does chimney repair cost in Leicester?
Costs vary widely. As a guide: simple repointing on a domestic stack typically starts around £700-£1,200 including scaffolding; full lead flashing replacement is often £600-£900; a full rebuild from sound course is usually £1,500-£3,000. We give a free written quote after seeing the job.