EPS70 polystyrene insulation boards — by the pack
Rigid EPS70 expanded polystyrene insulation in 25mm, 50mm, 75mm and 100mm, supplied as full 2400 × 1200mm boards (2.88 m² each). A lightweight, closed-cell board with 70 kPa compressive strength for solid floors under screed, suspended floors, lofts, flat roofs, walls, cavities and cold stores — the best cost-to-performance insulation on the market where space isn't tight. Not sure what to order? Use the two tools below: pick your job to get the right thickness, then enter your area for the cheapest pack combination.
Where it's used
One board that suits most of the building — swipe through common jobs.
What thickness do you need?
Pick the job and we'll suggest a starting thickness and show the insulation value (R-value) it adds.
EPS is one layer of the build-up — your final U-value depends on the other layers too. If you're meeting Building Regulations, check the whole construction (or ask us) before ordering.
How much do you need?
Choose your thickness and floor/wall area — we'll work out the cheapest pack combination and the exact price. Boards are 2400 × 1200mm (2.88 m² each).
✓ Free UK delivery — already included in the price
Coverage is rounded up to whole boards, then the cheapest pack mix that covers it. Add a little extra for cuts and joints. Need more than 100mm? Stack two boards (e.g. 100 + 50mm) — order both thicknesses.
EPS70 vs PIR vs mineral wool
EPS wins on price per m². PIR wins where thickness is tight. Choose on space and budget.
| EPS70 (this board) | PIR board | Mineral wool | |
|---|---|---|---|
| Thermal conductivity | ~0.038 W/mK | ~0.022 W/mK | ~0.035–0.044 W/mK |
| Cost per m² | Lowest | Highest | Low–mid |
| Thickness for same R | Thickest | Thinnest | Similar to EPS |
| Rigid / load-bearing | Yes — under screed & slab | Yes | No — soft batt/roll |
| Best for | Floors, slabs, walls where space is fine | Tight floors & roofs | Between studs & joists |
Specification
- Product: EPS70 expanded polystyrene insulation board (general purpose / floor grade)
- Board size: 2400 × 1200mm — 2.88 m² per board
- Thicknesses: 25mm, 50mm, 75mm, 100mm (stackable for greater depth)
- Thermal conductivity (λ): ~0.038 W/mK
- Compressive strength: 70 kPa at 10% compression
- R-value added: 25mm ≈ 0.66 · 50mm ≈ 1.32 · 75mm ≈ 1.97 · 100mm ≈ 2.63 m²K/W
- Structure: Closed-cell rigid foam — 98% air, 2% polymer · 100% recyclable
- Fire: Euroclass E (fire-retardant grades available on request)
- Fitting: Score & snap with a knife, hot-wire or handsaw · bond, mechanically fix or friction-fit
Good to know
Working to a specific U-value or Building Regs target? Message us your construction and we'll confirm the thickness — or whether PIR would be a better fit.
EPS70 polystyrene insulation sheets — rigid expanded polystyrene insulation boards in 25mm, 50mm, 75mm and 100mm, supplied as full 2400 × 1200mm boards (2.88 m² each) at trade pack prices. EPS70 gives the best cost-to-performance ratio of any rigid insulation, which is why these polystyrene insulation boards are the UK's go-to for floors, walls, roofs and cavities wherever board thickness isn't tightly restricted.
What is EPS70 insulation?
EPS stands for expanded polystyrene — a closed-cell rigid foam that is 98% trapped air and 2% polymer. The "70" is its compressive strength of 70 kPa at 10% compression, which is why EPS70 is rated for use under screeds and floor slabs. It is the same general-purpose floor grade sold as Jablite Jabfloor 70 and equivalent EPS70 boards. With a thermal conductivity of around 0.038 W/mK, these expanded polystyrene sheets deliver dependable thermal performance at the lowest cost per square metre of any insulation board on the market. EPS is rot-proof, moisture-resistant and 100% recyclable.
Where EPS70 boards are used
EPS70 is the most universal insulation board in the UK. Common uses include solid ground floors (as floor insulation boards laid under the screed or slab), underfloor insulation beneath heated floors, suspended timber floors between the joists, lofts and rafters, warm-deck flat roofs, internal wall linings, cavity wall insulation, cold stores, garden rooms and campervan conversions. Anywhere a rigid, load-bearing, cost-effective board is needed, EPS70 fits.
Thicknesses and coverage
Choose 25mm, 50mm, 75mm or 100mm polystyrene insulation, each supplied in packs of 6 to 60 boards — the larger the pack, the lower the price per square metre. Each 2400 × 1200mm board covers 2.88 m². Need more than 100mm? Stack two boards with staggered joints (for example 100mm + 50mm for 150mm) and order both thicknesses. Use the coverage calculator on this page for the cheapest pack combination for your exact area.
EPS70 vs PIR insulation
EPS costs significantly less per board than PIR but has a higher thermal conductivity (≈0.038 W/mK versus ≈0.022 W/mK for PIR), so EPS boards need to be roughly 50% thicker to reach the same U-value. Choose EPS70 where space is not constrained and cost is the priority; choose PIR where minimum thickness matters. Working to a Building Regulations U-value? Send us your construction and we'll confirm the right board.
Cutting and fitting
EPS is quick to work with: score with a sharp knife and snap, use a hot-wire cutter for precision edges, or a handsaw for speed. Boards are light, easy to handle and can be bonded, mechanically fixed or friction-fitted.
Related insulation boards
Building in a shallow floor build-up or under underfloor heating? Our XPS insulation board offers higher compressive strength and moisture resistance in a thinner board. Browse the full roofing & insulation range for foil insulation and polycarbonate roofing sheets.
Free UK delivery
All EPS70 polystyrene insulation sheets ship with free UK mainland delivery, typically in 3–5 working days. Boards are light but bulky, so please allow space to receive your pallet or parcels.