Underfloor Heating

5 Best Underfloor Heating Insulations

underfloor heating renovation within new home in attic room

Table of Contents

  1. Introduction
  2. The 5 Best Underfloor Heating Insulations
    1. Polyester Rolls
    2. Fiberglass Batt
    3. Rigid Expanded Polystyrene Panels
    4. Zig-Zag Foil Sheets
    5. Foam Board
  3. Conclusion


Underfloor heating insulation is the most efficient and ergonomic way of making homes warm. It is a method of stuffing the floors with rigid materials like foam, below or above the concrete. The materials fill the necessary gaps in floorings and prevent the heat from dissipating, keeping homes warm for a long time. 

The investment in underfloor heating insulation (£520 to £1,300) may initially seem steep, but it is known to save £50 per year on electricity bills. Plus, it requires minimal maintenance and lasts a lifetime, so it’s an excellent investment to keep the house warm during harsh weather conditions. 

Floor insulation is a charm, but knowing what type you need will bring maximum benefits and our team at the Floor Heating Warehouse, will walk you through the best insulations for your floors. 

What Is the Best Underfloor Heating Insulation?

Here’s a list of the five best underfloor insulations to keep your home warm.

Rigid Expanded Polystyrene Panels

The Rigid Expanded Polystyrene Panels or EPS panels are quite famous in the insulation industry. They have a high insulation value and are quite easy to install for both an underfloor water heating system and an electric underfloor heating system.

The Material of EPS panels is tightly packed together, which gives high thermal retention capacity. The panels need to be installed on even floors, and since they are resistant to pressure, they don’t crack floors. 

The pressure resistance feature makes them popular for concrete or hard floors. One of the best things about an EPS insulation panel is that it is adaptable. It can be installed to new properties and can be retrofitted as well. 

More layers can be added to increase the panels’ R-value and thickness and improve thermal resistance. EPS is also resistant to water, so it is more effective in insulating homes

Foam Board

Polyurethane core foam boards are quite popular for underfloor heating insulation as they are easily trimmable and adaptable to different types of floors. They usually come in 4’x8’ sheets and are quite lightweight, so installing them is a breeze.

What’s cooler about these boards is they even provide a moisture barrier, keeping both moisture and air intact, and providing additional thermal resistance. 

The foam boards cannot be fitted in small spaces as they need to be covered with sheetrock, which requires extra room. 

The foam boards have a high R-value, which makes them a preferred choice to batts as they have a higher thermal performance. The board comes in thick sheets and can be easily installed on different floors.

Polyester Rolls

One of the best ways to keep the house warm and cosy is through underfloor heating insulation, and polyester rolls are the most dependable insulators. They trap billions of air pockets between them and prevent heat from transferring from the floors.

20% of the energy is lost through the floors, and polyester rolls stop heating from transferring, which cuts down the electricity bills, and helps you save money. Additionally, it helps keep the house warm and stops draughts.

The polyester rolls are recycled plastic, making it a breeze to install and handle. It has no breathable fibres, so it’s good for people with asthma and allergies. 

Polyester rolls have a wide range of thicknesses and R-values to choose from. The higher the thickness, the more thermal benefits and acoustic advantages. 

They are ideal for timber floors and suspended floors where the rolls can be perfectly installed between the joists and secured with straps or saddles. 

Fiberglass Batt

Fibreglass is the most common type of underfloor heating insulation used between the attic floor joists. It is extremely reliable for insulating floors. The other types of batts include cellulose, natural fibres and plastic. 

The fibreglass batts usually come in dimensions that perfectly fit 2×4 walls and can spread over 40 square feet of floor spacing. The typical R-value of a common fibreglass batt is 3.25 per inch of batting and the more the layers of batts, the better the insulation. 

They are made from recycled plastic and are quite cost-effective. The batts work by trapping air inside their material, keeping the place warm by reducing heat transference.

The fibreglass batts are quite easy to install — so much so that you can even DIY them. 

Zig-Zag Foil Sheets

The best kind of underfloor heating insulation comes from materials that are best at keeping the air inside and preventing heat transference. The more air trapped in between the floor and insulation, the better the thermal protection. 

The Zig-zag foil sheets can be neatly fixed over floorboards, keeping the spaces intact to not let air pass by. This provides optimal thermal performance. 

The foil can be retrofitted to existing properties or spread over newly-built homes. Its material works best for both even and suspended floors. The foil’s airtight technology keeps the air inside and guarantees a warm natural temperature of a home. 

The foil sheet completely seals a floor and does not let even the tiny particles of air slip out, preventing as much energy loss as possible. It does not have a high R-value compared to other insulation methods, but it gets the job done. 

The sheets are made of fire-retardant aluminium, which gives them a high thermal performance and moisture resistance on top of a thermal break and vapor barrier. They can be easily joined with the tapes that come along with them in the package. 


Underfloor heating insulation is a charm if you want to wake up to a heated floor. They are energy-efficient, cost-effective and easy to install. They bring in multiple benefits once the right kind of insulation is installed on the right floors. 

You can contact our team for quotes and get your queries answered by our team of professionals. We provide free-of-cost assistance and quotes. You can reach out to us for consultation at: https://www.thefloorheatingwarehouse.co.uk/quote/ 

We are a dedicated team of underfloor heating insulation experts that believes in delivering quality to its customers.