Types of Floorwarming Systems
There are 3 main types of electric radiant heating (floorwarming) systems; cables kits, open weave mats and membrane backed mats. All three systems use specially designed heating cables to generate heat when connected to 120,208 or 240VAC power sources.
Membrane Backed Mats
The membrane backed mat is the optimum electric radiant floorwarming system; this type of mat comes in a large number of standard sizes and can be custom built to fit the exact room size, accommodating the curves and angles common in many room layouts.
Heatlay utilizes the tried and true dual membrane construction where the heating wire is "sandwiched" between outer textile membrane layers.
Heatlay mats are designed to bottom out on the subfloor, providing a flat surface for tiling whereas other systems may “float” and leave a somewhat uneven surface.
The membrane construction makes it easier for installers to see when they have proper mortar engagement (bonding). This bonding concept has been proven out by the fact that the Heatlay mats have been given an “Extra Heavy” rating by the TCNA.
Heatlay mats use a stainless steel braid over the heating cable and cold lead portions of the mat; it’s more expensive than copper or tinned copper braids but offers excellent resistance to the chemicals in concrete and adds a level of abrasion resistance.
Heatlay custom mats are built with outputs ranging between 12W/sq.ft-15W/sq.ft, the lower value for wood subfloors or over heated or insulated areas; the higher value for concrete or over unheated or uninsulated areas. Heatlay standard mats are built to 12W/sq.ft.
Heatlay uses a standard 14AWG cold lead, other manufacturer’s cold leads vary in size, and some appear to be one or two sizes smaller. The larger lead costs more but it is Heatlay’s opinion that the mat cold lead should be of the same minimum gauge required of house wiring.
Heatlay uses crimped connectors for both heating and ground connections in the hot to cold splice. Others use soldered connections to reduce the splice diameter. It is Heatlay’s opinion that a crimped connector provides a superior electrical connection and is worth the small sacrifice in diameter.
Installed product thickness is an important characteristic of membrane heating mats as they tend to be the thinnest on the market. At 1/8" Heatlay’s mats are as thin as any on the market.
Heatlay mats can be made up to 6' wide and 20’ long, some of the largest membrane dimensions in the industry.
The Coverage Myth
Cable kits are often advertised to cover a range of areas (e.g.; 12sq.ft to 20sq.ft) but the reality is that they fit one specific square footage (16sq.ft) and require concessions to fit the smaller or larger limits. To fit the lower limit the cable spacing is reduced in one part of the room which creates a zone hotter than the rest of the floor. To fit the upper limit large gaps are left along one or two walls, these gaps are cold spots. There is another method of making one kit cover a large range of areas, this time by Cheating the cable spacing. In this instance you get the kit covering one area with optimum heating (e.g.; 12W/sq.ft at 3” spacing) and then a larger area covered by increasing the spacing to 4” which reduces the heat output (by 25%) to a marginal 9W/sq.ft.
Open weave mats are sold in fixed rectangular sizes (e.g. 10sq.ft, 15sq.ft, etc...) and are similarly rather inflexible when it comes to fitting the exact room size. To install you roll out the mat, when you get to the end of the room cut the backing material and fold to run back in the other direction. Most have an adhesive backing which works well as long as the floor is very clean, any dust and the adhesives don’t stick. There is lot of cutting and pasting required to get a good fit and to get the heat where you want it to be. You often end up with large gaps at the end of the run or end up manually stringing out one strand of the heating cable to force heat into a particular area.
The membrane backed mat is the optimal system; this type of mat can be custom built to fit the exact room size, accommodating the curves and angles common in many room layouts. By offering a large number of standard models the installer also has the option of picking a “best fit” mat without the cut and paste problems. The mat is factory built and provides even heat across its surface. It is the easiest mat to install; it does not require any special installer skill level and goes down as fast as you can spread the mortar.
Time is Money
No matter what system you choose you are going to need to make an accurate measurement of the area to be heated. Do this measurement upfront and you have all the information you need to select the standard or custom Heatlay mat of your choice. Choose a cable or open weave system and your work has just begun.
Few if any cable or open weave manufacturers’ mention the time involved in planning and installing their products. Fewer still mention the fact that it may take 2 or 3 attempts to get the cable or open weave mat to fit the area properly.
Applying mortar over cables or open weave mats requires significant time and care. If not done properly the heating wires will shift or pop-up leading to subsequent tile problems. The process for installing Heatlay’s mat is much different, mortar is troweled onto a bare floor and the mats are simply pressed into the material. The membrane backing provides a clean smooth tiling surface.
If all the costs of a floorwarming system installation are considered, you will quickly see how Heatlay’s mat system simply becomes the best choice available.