Under Wood and Vinyl Installation
Under Wood and Vinyl Heating FAQ
Can underfloor heating we used under any wooden floor?
Unfortunately, not. Heating under natural timber is not recommended. Natural timber will warp and twist if not fixed directly to the floor joists. Nails and underfloor heating are not a good combination! Underfloor heating cannot be installed under existing wooden floors without significant cost.
Are there options if we want a natural wood flooring finish?
Yes. Happily, most wooden floors now are a machined wood or a wood composite. They do need to be the clip together style. The floor will expand and contract. If the machined wood or wood composite is not clipped together then you will develop gaps between planks. You do need to be careful that there is not insultation attached to the machined or composite wood. Ask your flooring supplier if your choice is suitable for underfloor heating.
Can underfloor heating be installed under Vinyl or Lino?
Yes. In fact, vinyl or lino over underfloor heating is a very efficient form of heating. The vinyl or lino cannot be plank style unless it has been specially designed not to expand or contract. Once again, gaps will form with the plank style vinyl.
What method of under-floor heating does Heatwell use?
Heatwell uses our exclusive Pro Series heating element. The Pro Series cable is attached to the floor, a fiberglass mat is placed over the top, a self-levelling compound or screed is poured over the top. The result is a heating element that is encased and protected from heavy furniture. We do not use a mat style system. We have found that heavy furniture can damage the heating element wire with a mat system.
How long does the self-levelling compound (screed) take to dry?
Please allow 24 hours. In cold conditions, drying could take more than 24 hours. Tiling or waterproofing should not be done if the floor is not fully dry.
When is the under machined wood or under vinyl heating installed?
Underfloor heating is done just before the final flooring product is laid. Installation of the final flooring product should not be done until the screed is fully dry.
Can under machined wood or vinyl heating be installed over the top of any type of floor?
Underfloor heating can be installed directly over concrete as long as there are no cracks, holes, or sharp protrusions.
Installation over the top of particle board or plywood however is not recommended. Expansion and contraction of particle board or plywood is a certainty in NZ’s conditions, Expansion and contraction risks cutting the electrical element where the flooring butts together.
How should particle board or plywood be prepped?
There are three excellent options. The most common is laying tile and slate underlay.
Another option is to lay 6mm insulation sheeting. Infinity from Tile Max is an example. Insulation sheeting has the big advantage of improving the efficiency of the underfloor heating and will save you money in the long run. The third option is to incorporate an anti-fracture rubber-based system. Strata Flex from Surtec is an example. This option is probably the most expensive, however, it adds the least to the floor height.
What condition does the floor need to be prior to under machined wood or vinyl heating installation?
All floors need to be clean, free of dust, and free of paint. They also need to be free of any cracks, holes or sharp protrusions.
A floor that is being renovated needs have all the remains of the previous flooring removed.
Is there any wall prep required?
Yes. We need a flush box for the thermostat / controller. The cold tails that are attached to both ends of the heating element must come up from the floor to the thermostat flush box. 25mm holes need to be drilled through the wall nogs. A 50mm wide and 25mm deep section must be checked out of the bottom plate of the wall. A draw wire from the thermostat flush box down to the bottom plate is essential. The flush box for the thermostat can be installed either vertically or horizontally. Heatwell has thermostat options for both.
What does the Electrician need to know?
A 900W element draws 3.91amps and is 58.78ohms in total. Any heating element 1000W or above needs a dedicated RCD circuit breaker back to the board. All our thermostats have a 15amp maximum capacity. We allow 150W per m2 for under machined wood heating. We allow 100W for under vinyl heating.
What does the final flooring installer need to know?
Please don’t drop anything sharp or heavy on the screeded surface. The installer needs to remember to allow a small gap between the edge of the flooring and the wall to allow for expansion and contraction.