We take a crumbling head down to sound masonry, rebuild it with frost-resistant solid bricks, cast a new crown slab and fit a cap if needed. Before the work we clean the flue and inspect it with a camera to know whether only the head is damaged. Describe in the form what you can see from the ground.
Why the chimney head is damaged first
The head is the only part of the chimney that is outdoors on all sides. Rain soaks it, in winter it freezes and thaws dozens of times, and from inside it is wetted by condensate if a modern boiler is connected to the chimney. Water soaks into the mortar joints, freezes and expands, and the joints gradually crumble out. If the crown slab has cracked or there is none at all, water runs straight into the masonry.
- crumbling mortar joints and loose bricks in the top courses;
- pieces of brick or sand on the roof and in the cleaning door;
- a cracked or broken crown slab;
- the head is leaning or a crack runs through several courses;
- damp, dark patches on the chimney in the attic under the roof.
If the masonry is damp from inside, a rebuilt head without a liner will crumble again after a few winters. In that case we recommend chimney liner installation together with the head. Read about the cause: condensation in the chimney.
How we rebuild a chimney head
- Cleaning and inspection We clean the flue and use a camera to check where the damaged masonry ends and whether the flue channel is sound inside.
- Protecting the roof Work on the roof is done with safety equipment. The roofing around the chimney is usually sheeted over so that debris and mortar do not damage it.
- Taking down We take the damaged courses down brick by brick to sound, hard masonry. We cover the flue channel so debris does not fall down it.
- Bricklaying We build with solid ceramic bricks that withstand frost and a mortar suited to chimneys. We keep the flue channel's cross-section and the wall thickness.
- Crown slab At the top we cast a crown slab with a fall and an overhang so water runs off away from the masonry, not down it.
- Cap and liner end If the chimney has a liner, we fix and close off its end. We fit a cap if needed: chimney cap installation.
- Check After the work we check the draught and clear leftover mortar from the flue.
The work is done by a qualified craftsman. Bricklaying is done only in frost-free weather, because mortar does not set in frost. If the head crumbles in winter, it is usually secured for the time being and rebuilt when the weather allows.
Height: a chance to correct a chimney that is too low
Old houses often have chimneys that are too low, because the roof was later rebuilt or raised. When the head is rebuilt, the courses needed can be added, and this is the cheapest moment to do it. The height required depends on how far the chimney is from the roof ridge. A chimney that is too low often has weak draught, and in windy weather smoke comes into the room. All the requirements with examples: chimney height above the roof.
LBN 231-15 (Cabinet Regulation No. 310 of 16.06.2015), point 61: if the chimney is closer than 1.5 m to the ridge, it must be 0.5 m higher than the ridge. If it is 1.5 to 3 m from the ridge, it must not be lower than the ridge. If further than 3 m, it must not be lower than a line drawn from the ridge at 10° to the horizontal. Point 62: the top of the chimney is set no lower than 0.5 m above the roof covering, also on buildings with a flat roof. Point 42: brick flue walls are at least 120 mm thick. Source: likumi.lv, checked 04.11.2026.
How much does chimney head rebuilding cost?
The price depends on how many courses must be taken down and rebuilt, the size of the chimney and the number of flue channels in it, the height of the chimney, the roof pitch and access. It also depends on whether a new crown slab, a cap or raising the chimney is needed, and whether we clean the flue and fit a liner on the same visit. Materials (bricks, mortar, concrete, cap) are priced separately from the labour. After you submit the form, the specialist will contact you, clarify the situation and name the price before the work. Other prices: prices.