Do I need to use insulation with Underfloor Heating?

If you want to save on energy costs then the installation of insulation boards with electric underfloor heating systems is highly recommended. In all cases, warmup times are reduced which lead to lower running costs.

Save on Underfloor Heating Energy Costs

  • The insulation increases the efficiency of the underfloor or undertile heating system used.
  • It will take less electricity to maintain your floor temperature setting.
  • Less energy is also wasted through the concrete or floor void.
  • If you are fitting undertile heating to an un-insulated floor then the use of insulation boards is especially important.

Using insulation boards with an electric underfloor system is not a cheap option.  You may need to budget about 50% of the cost of the cable mat heating system. However, with constantly rising fuel bills you will soon start to reap the benefits. If you read the Sunday Telegraph column by Jeff Howell, you will know that installing insulation is extremely beneficial, as long as it is fitted correctly.

Buy good quality insulation boards

Insulation boards can be called by different names depending upon the manufacturer, e.g. tile backer boards or marmox boards. Brands include Varme, Heatmat, Marmox and Wedi and boards come in a variety of thicknesses. However, not all boards are the same, so check the type you are going to use. Ensure your boards are coated, with some uncoated foam boards the tile adhesive may separate from the foam which could result in the floor lifting.

Varme tile backer boards are made of waterproof extruded polystyrene and are available in 6mm, 10mm, 20mm, 30mm, 40mm, 50mm and 60mm thickness.  They have a fiberglass mesh embedded onto each face into a cement polymer coating which provide exceptional compressive strength and rigidity. It also means they are suitable for use in a wetroom installation.

Varme Tile Backer Board

Varme Tile Backer Board

Deciding on the insulation board thickness

The board thickness you decide to use may depend on:

  • height restrictions
  • you need to bring the floor height up by a certain depth.
  • you may want to use the maximum amount of insulation board possible.

Generally, a 10mm board is installed as standard.

How to install your insulation boards

  1. You need to ensure the boards are fixed securely before fitting your underfloor heating and floor tiles.
  2. On a concrete floor, the boards should be adhered with the use of a rapid tile adhesive such as 20kg Ultra Rapid PB.
  3. For wooden floorboards, chipboard or plywood fix the boards with both rapid tile adhesive and galvanised screws at regular intervals.

For more information or to purchase tile insulation boards visit the insulation section of the Creative Tiles and Laminates website. Or if you require help in deciding which board to choose or need further advice, please call on 01922 610015.


About Susan

Joined Creative Tiles and Laminates as Marketing Manager in 2005. Complementing the senior management team containing 30+ years experience of fitting, flooring and customer services.
This entry was posted in Floor Tiles, Underfloor Heating and tagged , , , , , , . Bookmark the permalink.

13 Responses to Do I need to use insulation with Underfloor Heating?

  1. Nick Robinson says:

    We have ceramic tiles going onto concrete floor with no room for insulation under the under floor heating due to height restrictions. We have radiators to heat the room, so the ufh is just there to take the chill off the tiles in the winter. Is this ok, or should we consider digging down further at great expense?

    • Susan says:

      Hi Nick
      You will incur further expense digging down further but at least when you have the underfloor heating switched on you will reap the full benefit. Given time it will pay for itself as the underfloor heating will run more effectively both in terms of performance and cost when combined with an insulation board.
      Although we traditionally install a 10mm tile backer board, a slimline 4mm board is now available from the manufacturers (although it does cost the same as the 10mm board). Perhaps this thickness is more workable for you – it won’t provide as much insulation as the 10mm board but it will still be better than none.
      All the best

  2. Ed Evans says:

    Hi Susan. I want to lay ceramic tiles on a chipboard bathroom floor. I also want to see install electric UFH. I understand the need to use a backer board to stiffen the chipboard flooring. I also understand the need to use an insulation board under the UFH. Can 1 board do both roles? If yes won’t the need to screw the backer board in a 300mm grid transfer heat thus negating the effect of the insulation board?

    • Susan says:

      Hi Ed
      Thanks for your message. Yes, you do need to make the flooring more rigid when tiling onto a boarded floor and it is always recommended to use an insulation board alongside the underfloor heating. For a bathroom floor, I would suggest using the No More Ply board as both your tile backer board and insulation (it will do both of these things). Fix the No More Ply boards with screws and glue and also prime the boards before fitting the underfloor heating and tiles. You can find more details about these products on our site using this link No More Ply boards.

      All the best

  3. Kay says:

    Hi Can you tell me I have ordered from you the underfloor heating mats along with the insulation boards. Do the boards have to be stuck onto the concrete? Also I didn’t order the levelling compound or adhesive with my original order as I thought my installer would be able to purchase this but he has told me to. Can I order this from you?

    • Susan says:

      Hi Kay
      Yes, the boards have to be stuck down onto a concrete floor and you can use tile adhesive to do this. Yes, we supply you with both the tile adhesive and levelling compound that you require.
      Kind regards

  4. Tim says:

    Hi : I’m looking to replace carpet in my loft bedroom with laminate flooring and electric UFH. I’m concerned about height loss particularly the need to adjust doors. I understand the efficiency point but the UFH won’t be the primary heating for the room and the room below is another bedroom. Could I get away with none or a minimal thickness of insulation board?

    • Susan says:

      Hi Tim
      Normally it’s about the same height. We recommend a minimum insulation board of 6mm. With 6mm insulation, 1mm heating element and 8mm of laminate this gives you 15mm high and a fairly good comparison to the carpet and underlay in terms of height.

  5. Chris says:

    Hi! I would like to ask if i will hve heat losses because my contractor made holes in my polysterene insulation to be able to measure tha screed on top better!

    • Chris says:

      For example in one room there are 12 hole 10×15 cm! Will my gas underfloor heating work more to heat my room?

      • Susan says:

        Hi Chris

        Unfortunately, we only have experience of installing electric underfloor heating so cannot comment regarding the holes in your insulation for a wet based system.
        I’m sorry I can’t be of further assistance.

  6. Paul Rattue says:

    Hi I want to put under floor heating in my bathroom which is only 1200mm x 3m I am restricted to height.
    Does insulation have to be used? and if so what is the minimum I can use?

    • Susan says:

      Hi Paul
      In a bathroom, insulation is not normally essential as there are many more heat losses. However the running efficiency of the underfloor heating system will be improved with insulation. The thinnest tile backer boards that we supply are 4mm.
      Kind regards

Leave a Reply

Your email address will not be published. Required fields are marked *