Installing a Wood Stove If You Already Have a Chimney

If your home already has a built-in fireplace or open fireplace, which are often very inefficient, it can usually be removed. After demolition, the fireplace opening remains, and you can either:

• choose a wood stove that fits the existing opening, or

• expand the opening to install a larger stove.

If the fireplace opening is too small for the stove you want, the fireplace area can be completely closed with masonry, and the new stove pipe can be connected higher up in the chimney.

If you already had a wood stove that you want to replace, the process is simple:
disconnect the old stove and install the new one.

Many people ask:

“Can my existing chimney be used for the new stove?”

In most older homes the answer is yes.
Often the chimney will simply need a chimney liner, but the structure itself is usually suitable for installing a new wood stove.

In more modern houses you may encounter Class 2 ventilation chimneys, which sometimes look like narrow rectangular shafts.

These are usually designed only for gas heating appliances and are not suitable for wood stoves.

However, if your house has a traditional brick or stone chimney, it is generally suitable for wood stove installation.

Installing a Wood Stove If You Do Not Have a Chimney

The first question to consider is:

Where in the room should the wood stove be located?

You must consider several safety factors.

For example:

• Avoid placing the stove near curtains, as drafts from windows could move them toward the stove and create a fire hazard.

• Do not place the stove close to cabinets, shelves or furniture.

• Keep a safe distance from wall lamps and electrical outlets.

Floor Protection

A wood stove must be placed on a heat-resistant base, which can be made from:

• stone

• tiles

• metal

• glass

Wall Materials and Safety Distances

According to Latvian building regulations LBN 231-15 (Heating and Ventilation of Residential and Public Buildings):

The safety requirements are met when the distance from the outer surface of the stove or fireplace to combustible wall or ceiling materials is at least 500 mm.

The floor beneath the stove must be non-combustible, or covered with a non-combustible sheet extending:

• 150 mm beyond the stove footprint, and

• 300 mm in front of the stove door for closed combustion appliances.

The protective material should be at least 6 mm thick.

If fire-resistant gypsum board or other protective materials are used, the distance to the wall may be reduced according to the stove manufacturer’s instructions.

Ceiling and Roof Considerations

When installing a chimney through the ceiling and roof, it is important to understand how the roof rafters are positioned.

If your house has a second floor, you can usually determine the direction of the beams by looking at the floorboard nails.

If not, you may need to inspect the attic.

The chimney should be positioned so it does not pass directly through a structural beam or rafter.

Chimney Routing

The chimney should pass through floors and the roof as straight as possible.

Too many bends can reduce chimney draft.

A proper chimney system should generally have no more than two offset sections, and the total length of angled sections at 45° should not exceed 20% of the total chimney height.

For example:

• If the chimney height is 5 meters, angled sections should not exceed 1 meter in total.

External Chimney Installation

Ideally, a chimney should pass through the interior of the house, which improves heat retention and chimney performance.

However, if this is not possible, the chimney pipe can exit the house at a 45-degree angle and then run vertically along the exterior wall.

When installing an external chimney:

• choose a straight wall with minimal obstacles

• avoid areas with gutters or structural obstructions

The gable wall of the house is often the best location for external chimney installation.

Chimney Height and Clearance

Once the chimney is installed—either through the house or along the exterior wall—the chimney top should be positioned so that it is at least 2.3 meters horizontally away from nearby obstacles or structures.