Fastwarm® 50mm XPS Insulation Boards are our thickest and most thermally efficient option—designed to maximise energy retention in underfloor heating installations over concrete or screeded bases. Ideal for large spaces or where energy-saving is a priority.
Despite their thickness, the boards remain incredibly easy to install and offer robust acoustic and compressive performance. An excellent choice when insulation is key.
- Ultra High Insulation – Thermal conductivity rated at 0.031 W/mK.
- Thickest Profile – Maximum thermal and sound insulation at 50mm.
- Tile & Floating Floor Ready – Works under a wide range of floor finishes.
- Easy Installation – Trim on-site with basic tools.
- Heavy-Duty Performance – Withstands 30 tonnes per m².
- Compatible with Ultra Tile Adhesives – Reliable bond strength.
- Board Size – 1200mm x 600mm (0.72m²).
Installation Guidance
The Fastwarm® XPS insulation boards can be used beneath both tiled flooring and floating floor installations (such as laminate or engineered wood). However, installation methods will vary depending on the type of flooring and subfloor surface.
Undertile Installations:
Fix boards to the subfloor using a suitable flexible tile adhesive. When tiling over a timber subfloor, we recommend using our dedicated Fastwarm® Tile Backer Boards, which can be mechanically fixed in addition to being bonded with flexible adhesive.
Underwood Installations:
Lay the XPS insulation boards directly onto a clean, dry, and level subfloor in a brickbond pattern. Secure the joints using our heat-resistant Fastwarm® Duct Tape for added stability beneath floating floor finishes.
Please note: Boards are supplied in black. Blue colour shown in some images is for illustration only.
Choose the ideal board thickness to suit your project's build-up and insulation needs: 6mm | 10mm | 20mm | 30mm
| Thickness | 6mm, 10mm, 20mm, 30mm & 50mm |
|---|---|
| Board Dimension | 1200mm x 600mm |
| Material Type | Expanded Polystyrene |
| Thermal Conductivity | 0.031 W/mk |
| Material Density | 33 kg/m3 |
| Compressive Strength | 30 t/m2 |
| Moisture Absorption | < 0.1 vol % |
| Euroclass Fire Rating | E Euroclass |
Our August Bank Holiday Delivery Times
| Order Date | Order Time | Expected Delivery Date |
|---|---|---|
| Thu 21st August* | Before 4:30pm | Fri 22nd August |
| Thu 21st August | After 4:30pm | Tues 26th August |
| Fri 22nd August* | Before 4:00pm | Tues 26th August |
| Fri 22nd August | After 4:00pm | Wed 27th August |
| Sat 23rd August | All day | Wed 27th August |
| Sun 24th August | All day | Wed 27th August |
| Mon 25th August | All day | Wed 27th August |
Free Delivery as Standard!
As standard we include 2 - 3 working day delivery on all orders delivered to the UK mainland. * A £5 delivery charge will be applied to all orders below £20.
Delivery cut off times
Our final delivery time for Mondays to Thursday is 4:30pm. To give us a bit more time to ensure weekend deliveries are handled and our couriers have time to collect, the final delivery time on Fridays is 4:00pm.
2-3 working day delivery
Next working day
Next working day before 10:30
Saturday Delivery
* A £5 delivery charge will be applied to all orders below £20.
Other Delivery Options
Pre 10:30am and Saturday delivery services are available on orders placed before 4:30pm. Any order placed before 4:30pm on a Friday will be delivered on the following Monday (unless its a bank holiday) so please select a Saturday service if a weekend delivery is required.
Delivery outside the UK
Delivery outside the mainland UK may be arranged by prior agreement. You will be notified of the amount of the charge for this service and will at that point have to make a decision whether you wish to proceed wth 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.
