How to condition wood floors for underfloor heating

Conditioning Wood Floors

Whenever possible use kiln dried timber from a reputable manufacturer. The kiln drying process removes moisture from the wood, but it is not ready for use straight away because moisture can be absorbed during storage and transportation. For centrally heated properties the moisture content of kiln-dried wood is approximately 10 - 12%. For under floor heating you need to look at 7 - 10%

Step 1 - Allow the concrete and screed to cure

Before turning on the underfloor system allow the screed and concrete to fully cure. A period of 30 days is usually recommended although this can vary and you should check with the contractor / specifier.

Step 2 - Allow the concrete and screed to dry

After the concrete and screed have cured it still needs to dry out. The generally accepted figure for natural drying rate is 1mm per day. You should aim for a moisture content in the floor on not more than 5%, or a relative humidity of 75% which is measured using a hygrometer following the method outlined in BS8203

Your under floor heating system can be used to assist with the drying out BUT the water flow temperature must be increased to operating level (50°) slowly. Start at 30°C then increase this by 5°C every day. With a Continental underfloor heating system this is easily adjusted at the manifold.

Step 3 - Condition the timber

Loosely lay the wood floor over the floor heating area with the under floor heating system running at operating temperature and the room thermostat set to your usual preference. Allow the wood to condition like this for a period of 5 days or longer.

Step 4 - Fit the floor

Fit the floor following the manufacturers instructions.

Laminates

Laminate floors are very stable, and with the modern glue-free interlock system can be laid very quickly. Generally a laminate floor is laid as a 'floating floor' i.e. it is not fixed down and has an expansion gap around the perimeter and doorways. In non under floor heating properties laminate is often laid on a 3mm combined vapour barrier / foam insulation. With under floor heating you can dispense with the insulation and just use a vapour barrier, although some people still choose to keep the insulation.

Hardwood Veneers

These are becoming more popular. They have good stability and work well with under floor heating. They are often laid as a floating floor onto builder's paper.

Hardwood Floors

Often these are kiln dried to too low a moisture content, so they have to condition back to the ideal. Try to allow an extra 5 days conditioning.

Softwood Floors

Generally these have high moisture content so conditioning needs to be carried out diligently. Try to allow an extra 5 days conditioning.

If you want further advice please don't hesitate to call us on 0845 108 1204

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Underfloor Heating