Fastwarm® Classic Underlay Insulation Boards are a cost-effective and practical solution for improving thermal efficiency beneath underwood and undercarpet foil heating systems. Designed specifically for use with foil-based heating, these 6mm thick EPS boards also provide excellent support as a traditional underlay for floating floors, such as laminate or engineered wood—even in spaces without underfloor heating.
- High Thermal Performance – Delivers a thermal conductivity of 0.034 W/mK, helping to minimise heat loss and reduce energy consumption.
- Strong & Moisture-Resistant – High-density EPS construction (32 kg/m³) with excellent resistance to moisture (<0.1 vol%).
- Sound Reducing – Offers up to 20dB impact sound reduction, improving acoustic comfort in residential and commercial applications.
- Lightweight & Easy to Fit – Supplied in manageable 850mm x 600mm boards, each covering 0.51m², for quick and simple installation without specialised tools.
Please note: Classic Underlay is only suitable for use with foil heating mats and should not be used with electric undertile heating systems or beneath levelling compounds. For thicker or alternative insulation needs, see our XPS Insulation range, available in multiple thicknesses.
Each sealed pack contains 20 boards and covers a total area of 10.2m², making it ideal for small to medium floor areas needing fast and effective insulation.
Need more coverage? Try our 6mm EPS Insulation Pack Covers 20m² (40 Boards) or 6mm EPS Insulation Pack Covers 30m² (60 Boards).
| Thickness | 6mm |
|---|---|
| Board Dimension | 850mm x 600mm |
| Material Type | Expanded Polystrene |
| Thermal Conductivity | 0.034 W/mk |
| Material Density | 32 KG/m3 |
| Load Strength | 10 t/m2 |
| Moisture Absorption | < 0.1 vol% |
| Sound Impact Rating | 20db |
| Euroclass Fire Rating | C Euroclass |
Delivery Options
2-3 working day delivery
Next working day
Next working day before 10:30
Saturday Delivery
Delivery cut off times
Our daily cut-off time for dispatch is 4:30pm Monday–Thursday and 4:00pm on Fridays. Orders placed before the cut-off time will be dispatched for next working day delivery (if this option is selected). Orders placed after 4:00pm on Friday will be dispatched on Monday for Tuesday delivery.
Bank holidays may affect these delivery times, so please contact our team if unsure on 01268 744479
Other Delivery Options
PRE-10:30AM and Saturday Delivery services are available, but orders must be placed before the relevant cut-off times.
NOTE: All orders placed on a Friday will be delivered on the following Monday (unless its a bank holiday), unless a Saturday Delivery service is selected and paid for before the 4:00pm Friday cut-off.
Delivery outside the UK
Delivery outside mainland UK may be arranged by prior agreement. You will be advised of the delivery charge before dispatch, at which point you can decide whether you wish to proceed with your order.
Important: Our deliveries rely on third party couriers, so, whilst we make every effort to deliver your order on the specified date and time, unfortunately there may be occasions when this will not be possible due to external influences. Due to this we strongly recommend you ensure you have received your order before any tradespeople/builders are scheduled to commence work.
Still Unsure? Talk to an expert
If you need any guidance or further information our highly experienced team are on hand to help.
Get in touch using our contact form or give us a call on 0800 023 4203 or 01268 744 479.
