In this continuation of our Wood Effect Tiles series, where we compare them to natural timber floors, we examine a further issue which should be taken into account before making your choice between the two.
Heating your home from underneath is becoming more popular. There're a number of issues to be aware of when coupling underfloor heating with your choice of flooring.
Wood Effect Floor Tiles:
- Any ceramic or porcelain tile is perfectly suited to the demands of fluctuating heat. Kiln fired at upwards of 800° Celsius, they are more than capable of withstanding the range of temperatures expected in a domestic setting. They are excellent at transferring heat from the sub-floor into the room.
- Tiling can be done within the first couple of days after the pouring of a screed.
- Crucially, the adhesive and grout must be flexible. As always, it’s wise to consult the manufacturer’s technical data sheets to ensure you have the correct material. In the event that, for some reason, a non-flexible adhesive is used, there’s a high chance of the bond failing due to the rigidity of the adhesive, and the wood effect tiles could crack, loosen, or both.
- It’s a similar situation with grout. As the imperceptible fluctuations in the width of the joint require a certain yielding of the grout, when that yield is not present, the grout can crack and eventually fall out.
Installing wood over underfloor heating requires extra attention when choosing, preparing, and laying your floor. Here are some complications that arise, almost all to do with moisture content and expansion problems:
- Most wood manufacturers will recommend that wood flooring is stored in the building to acclimatize to the conditions in which it will be installed, with 7 days often being cited. These 7 days allow for the new heating system to run through a full top to bottom cycle, increasing in 5° Celsius increments to about 27°, held there for two days, and then back down in similar reductions, and then shut down for the final two days.
- Keeping the new wood in the building during this process helps it synchronise with its new environment. Bear this in mind if you find yourself in a hurry or under pressure to decide on a product.
- Many suppliers do not recommend solid wood flooring for this reason, recommending engineered or laminate products instead.
- The moisture content of the new solid or engineered floorboards themselves needs to be about 10 – 11% prior to installation, as that will reduce to 8 or 9% when the heating system is activated. Due to the high moisture content of certain species, such as beech or maple, some suppliers do not recommend these for use over underfloor heating.
- When laying timber there are always floor temperature, air temperature, and humidity parameters to adhere to for correct installation. The ambient temperature of the room will fluctuate during the year, so you must make sure you comply with the manufacturer’s guidelines.
- If installing onto plywood sheets, it’s important they do not hold more than 10% moisture content. Again, this is to guard against the contraction of the sheet inflicting damage on the new floor above as it dries out over time.
- Moisture levels of sub-screeds must be below certain levels, (3% for concrete, 0.3% for anhydride). For new builds, this means that the drying time needs to be taken into consideration. The recommended way to perform the moisture test is to drill a 50mm hole in the screed every 5 metres, taking care not to damage the underfloor heating system itself, and to take measurements with a hygrometer.
- Underlay, if used, must be thin, and have no reflective foil. Otherwise you will be insulating the floor itself from the heat.
- Using thicker planks will slow down the time it takes before the heating system begins to take effect. Boards thicker than 18mm will need to be used at a lower output.
- Another concern is the density of the wood in question. Higher density woods will conduct the heat better. The lowest density woods will take substantially longer to transfer heat.
To Wrap Up:
When installed correctly, you should have no problems with either wood effect tiles or natural timber. We’re happy to have alerted you to a number of caveats and pitfalls involved. Whichever you choose should bring you years of satisfaction, and warm toes.
Note that the images above are of wood effect tiles, and you can find our full selection of wood effect tiles here.