Underfloor heating is becoming an increasingly popular method of keeping homes nice and toasty, especially as it frees up space otherwise taken up by a radiator and provides an even spread of heat throughout the room. Yet, many people are worried over the safety of placing intricate carpets or designer rugs on heated floors. Happily, it’s still possible to decorate your floor space despite the wiring hiding beneath the tiles but there are a few factors you will need to consider before choosing your contemporary rugs or carpets.
Electric underfloor heating vs. water underfloor heating
Before even thinking of a suitable rug, you must first decide on one of the two types of underfloor heating. Electric underfloor heating (image above, right) consists of cables that use electricity as a heat source which are placed underneath the flooring, with vinyl or laminate flooring materials being the best for this type of heating.
The more expensive variant is water-based heating (image above, left) which works by connecting a web of pipes to the boiler with the hot water bringing ambient heat into the room and though it works well with carpets and rugs, the system is bulky so your floor would likely need to be raised slightly during installation.
How rugs can work on heated floors: tufted vs. knotted construction
While the water-based underfloor heating is not usually impacted negatively by the rugs or carpets, it’s a different story for electric heating. With the latter heating system, a rug could act as an insulator which interferes with the circulation of heat leading to a rise in electricity costs. This can be especially damaging to timber floors which can only be heated to 27°C, making them vulnerable to any tapped heat. To a rug or carpet with glued pile, or a tufted rug with a canvas glued on its back, overheating can soften the glue, causing waves to form once the material cools down again. This would affect both the rug and the floor.
Overall, it’s best to chose a rug that doesn’t retain heat, ideally made from natural fibres without a glued canvas on its reverse side to avoid blocking heat circulation. A hand knotted rug is ideal in this case. While our hand tufted rugs have a canvas glued on the back, all of our designs can be made in hand-knotted construction, so all our rugs, if hand knotted, are ideal to place over heated floors. See below the pile height difference between a hand tufted rug, with has a canvas glued on the back (left) and hand knotted rug, no canvas (right).
Rug materials, shapes and sizes most suitable for underfloor heating
As mentioned previously, rugs made from natural fibres can be a good fit for underfloor heating systems as they conduct the heat and release it quickly, unlike synthetic fibres so it’s best to focus on wool, silk or hessian materials. All of our rugs are made from 100% New Zealand wool, or Chinese silk, sometimes a mix of the two natural fibres.
When you choose to place a rug on your heated floor, it is best to not cover to not cover large areas of the floor, as even the best of materials will still reduce the spread of heat throughout your room. One practical and beautiful alternative is to choose runners. A well chosen runner will bring ambience and style to the room and at the same time, by being narrow, will allow the heat to circulate, not causing issues with the underfloor heating.
If you do choose a rug, instead of a runner, consider its size and the furniture arrangement. With underfloor heating it is best to have an all-off style arrangement (see the image below), where the rug sits in front of, not underneath the furniture, this way allowing the floor to breathe.
The best rug thickness for heated floors
The advice from most heating companies has been to recommend rugs and carpets of a thermal resistance that is less than 1.5 togs. On a practical level, this means that your rug should not be exceedingly thick with a high pile height as this traps the heat within the fibres. Recent research by The Carpet Foundation, in partnership with the Underfloor Heating Manufacturers Association (UHMA), has shown that the thermal insulation value should not add up to more than 2.5 togs when the ratings of the rugs or carpets are combined with the tog levels of the underlay.
It’s best to seek advice from your heating company if you’re thinking of placing a rug or carpet across a large proportion of your room and be sure to watch out for the tog values of any carpets you’re purchasing. It is best to consider using natural fibre materials that are hand-knotted and not felt-backed, with lower pile heights that do not sprawl across your entire space. If you’d like any further advice about suitable rugs from our range, please feel free to contact us.