Chimney liner installation in Riga and the Riga region

Why an old chimney needs a liner

Most old brick chimneys were built for masonry stoves and cookers, whose hot flue gases dry the flue out. A modern boiler works differently: it uses most of the heat itself, and the flue gases enter the chimney much cooler. With a condensing gas boiler they are only a little warmer than room temperature and full of water vapour.

On a cold brick wall the vapour turns into water. This condensate is acidic: it soaks into the mortar and bricks, freezes in winter and crumbles the masonry. The signs are brown patches on the chimney in the attic, damp walls around the flue, a smell and fallen bricks above the roof. More on the causes: condensation in the chimney. The second problem is size: the old flue channel is often much wider than the new appliance needs, so the flue gases move slowly in it and cool down, and the draught becomes weak.

A liner solves both. The flue gases travel through a smooth, acid-resistant pipe with a diameter suited to the appliance, the condensate runs down to a collector, and the old masonry serves only as a casing.

When chimney lining is needed and when it is not

• You are connecting a condensing or open-flue gas boiler to the old flue: liner for a gas boiler.
• You are replacing a wood stove with a pellet boiler, a wood boiler or a stove fireplace with a smaller flue outlet.
• The flue has cracks or you can smell smoke in the attic, but you do not want to rebuild the chimney.
• An inspection after a soot fire found damage: chimney check after a soot fire.
• The technical condition certificate states that the appliance must not be connected to the existing flue.

A liner is not needed if a masonry stove or cooker runs on a sound flue of the right size and the inspection found no cracks. Then regular chimney cleaning is enough.

Stainless steel or ceramic liner

In existing chimneys we most often fit a stainless steel liner. It has thin walls, so it takes up little of the old flue channel's cross-section, it is light and it can also be fed into a flue with a slight offset. For a gas boiler acid-resistant steel is used, while solid fuel needs a thicker liner tested for soot fires.

A ceramic liner is heavy and withstands very high temperatures, but it needs a straight, wide flue channel and a solid base at the bottom. That is why it is used more often in new chimneys or in a rebuild when the flue can be opened up. A comparison of both by appliance: ceramic or stainless steel liner.

Diameter: set by the appliance, not by the old chimney

The liner diameter is set by the appliance manufacturer's installation instructions, the height of the flue and how many bends there are along the way. A liner that is too wide cools the flue gases and causes condensation; one that is too narrow cannot carry away all the flue gases, and they may get into the room. The building code also sets a minimum flue channel cross-section. In rectangular flue channels where a round liner does not fit, an oval liner can be used.

Insulation and draining condensate

If the chimney runs through a cold attic, along an outside wall or high above the roof, we fit an insulated liner or wrap a single-wall liner in non-combustible insulation. This keeps the flue gases warmer and the draught steadier, and reduces condensation: chimney insulation. At the bottom of the liner we install a T-piece with a cleaning door and a condensate collector. For an appliance running in wet mode, condensate is drained through a siphon, as the appliance manufacturer specifies.

How a chimney liner is installed

1. Request In the form, say which appliance you will connect, the number of storeys and how the roof can be reached. The specialist will contact you and clarify the details.
2. Cleaning and camera We clean the flue and lower a camera into it. We see cracks, offsets, obstructions and the exact cross-section. About this job: camera inspection.
3. Measurements and quote We measure the length of the flue and choose the material, diameter and insulation. We name the price before the work.
4. Preparing the flue We remove old obstructions. If the flue channel is too narrow or has protrusions, we widen it so the liner goes in freely.
5. Lowering the liner We join the liner sections and lower them into the flue from the roof. Spacers hold the liner in the centre of the flue channel.
6. Bottom section We install a T-piece with a cleaning door and a condensate collector so the liner can be cleaned and inspected.
7. Top section We fix the end of the liner on the chimney's crown slab, close off the top and fit a cap if needed: chimney cap installation.
8. Draught and certificate After connection we check the draught. If the heating appliance has been replaced, before the new appliance is used we draw up a technical condition inspection certificate stating whether it may be connected to the flue.

The work is done by a qualified chimney sweep, and the certificate states their qualification document. Photos or video are attached to the technical condition inspection certificate, as the regulations require.

Liner for a pellet boiler

A pellet boiler is the trickiest case. It often runs at low output, the flue gases are cool and moist, but the fuel is solid, so fine ash builds up in the flue and tar can form. Such a boiler needs a stainless steel liner suited to solid fuel that withstands a soot fire, not a thin gas boiler liner. In a cold chimney it is almost always insulated, with a condensate collector at the bottom.

A pellet boiler usually meets the definition of a long-burn appliance, so its flue is cleaned twice a year: pellet boiler flue cleaning.

How much does chimney liner installation cost?

A two-storey house chimney with an offset and a straight summer house flue are completely different jobs. The price depends on:

• the length and diameter of the flue, and the liner shape (round or oval);
• the material: steel type and thickness, insulated or single-wall liner, ceramic system;
• the condition of the old flue: whether it must be widened, whether there are offsets and obstructions;
• the height of the chimney and access to the roof;
• the fuel and type of appliance, which determine the parts at the bottom and top (T-piece, cleaning door, condensate collector, cap);
• whether we do the cleaning, camera inspection and certificate on the same visit.

Materials are priced separately from the labour. In the form, give the appliance and the number of storeys. The specialist will assess the situation and name the price before the work. Other services: prices.

We fit liners across Riga and the Riga region, including old timber and masonry houses in Āgenskalns and Mežaparks, and in Jūrmala and Sigulda.