Electric Underfloor Heating Mats: A Selection and Planning Guide

Which electric heating mat should you choose?

Start with your floor design, the heat output needed and the area you plan to heat. Floor build-up means the layers under your finished floor. Then compare S-Mat 150 and SH-Mat 200 and select a listed mat size that fits the layout.

The two ranges differ in power, cable thickness and wiring. Higher output does not mean higher efficiency. Check the product against your floor construction and electrical requirements before ordering; the comparison below shows the differences.

How electric heating mats work

Each mat has a heating cable attached to self-adhesive mesh. It sits in the floor layer specified for that product and works with a suitable thermostat and floor sensor. Start by confirming the floor design, heated area and required output, then choose the controls and accessories.

Plan the complete floor build-up

Plan the heating mat together with the floor finish, adhesive or screed, controls, waterproofing and any layers needed to reduce sound.

Cable thickness is only one part of the finished floor height. Allow for the adhesive or screed, floor finish and cable connections too.

The drawing shows a floor finish, screed, heating mat, waterproof membrane and structural slab. It is an example: the mat position and the order of the layers must follow the selected product's instructions and your floor design.

Confirm the full floor layout before installation, including any waterproofing or sound-reducing underlay.

Work out the heated area before choosing a size

The heated area is the part of the floor covered by the heating mat. It may be smaller than the full room area. Show fixed cabinetry, baths and other fixtures on your plan so the layout, required clearances and any areas to leave unheated can be confirmed against the selected product's instructions.

For example, an 8 m² room might have a confirmed heated area of 5 m². Use that 5 m² area when checking the listed mat sizes. The mat layout must also fit the room shape and connection position; area alone does not confirm a fit.

Both ranges use 0.5 m-wide mats, with lengths varying by heated area. Confirm the mat layout before choosing the product reference.

How to read a mat reference

A mat reference gives the total output in watts followed by the heated area in square metres. SHMAT 750-5.0 is a 750 W mat covering 5 m² in the S-Mat 150 range. The 5 m² SH-Mat 200 option is SHMAT 1000-5.0, rated at 1,000 W.

These are rated outputs, not a running-cost estimate. Energy use also depends on how long the heating runs, the floor construction, insulation and temperature settings.

Choose a mat-only product or kit

SHMAT identifies a mat-only product. SHMATK identifies a kit. For example, the kit reference corresponding to SHMAT 150-1.0 is SHMATK 150-1.0.

The brochure's Wi-Fi thermostat kit includes:

• Heating mat
• Wi-Fi thermostat
• Floor sensor
• Screamer warning device
• Wall mounting box

Contents apply to the selected package. Confirm the thermostat, sensor and accessories when ordering; mat-only products are supplied separately.

Before you order

1. Confirm the heated area and selected mat range.
2. Match the area to a listed mat reference and output.
3. Check compatibility with the proposed floor finish.
4. Confirm the complete floor build-up, including waterproofing or acoustic layers where required.
5. Select the thermostat and floor sensor.
6. Confirm whether you need a mat-only product or a kit, and check the supplied accessories.
7. Follow the product installation instructions and arrange the electrical connection with a licensed electrician.

If you need help planning beyond the mat selection, explore SmartHeat's electric heating and project delivery services before finalising the floor assembly.

For the product specifications and warranty summary, download the SmartHeat electric heating mats brochure (PDF). Check the installation instructions and full warranty terms for your selected product before ordering.