Polystyrene Insulation Sheets UK | 25–100mm EPS Boards

1. What are EPS polystyrene insulation sheets?

EPS (Expanded Polystyrene) sheets are lightweight thermal insulation boards commonly used for walls, floors, lofts, sheds and outbuildings. They offer strong heat-retention performance while being easy to cut and install.

2. Which thickness should I choose?

• 
  25mm – Ideal for small spaces, lining walls, van insulation, or adding extra layers.
  
• 
  50mm – Great for sheds, garages, summerhouses and general wall insulation.
  
• 
  75mm – Stronger thermal performance for colder spaces or external walls.
  
• 
  100mm – Best for lofts, roof insulation, high-performance builds or outbuildings used year-round.
  

3. How many sheets come in a pack?

We offer pack sizes from 6 to 30 sheets, depending on your project size. Larger packs offer better value per sheet.

4. What size are the sheets?

Standard sheet dimensions are 1200mm × 450mm (or equivalent depending on supply). EPS sheets are designed to be easy to handle, transport and cut.

5. Are these insulation sheets moisture-resistant?

Yes. EPS naturally resists moisture, making it suitable for sheds, garages, lofts, internal walls and many outdoor building applications.

6. Can I cut the insulation myself?

Absolutely. EPS is extremely easy to cut with:

• 
  A sharp knife
  
• 
  A handsaw
  
• 
  A hot-wire cutter (optional)
  
  This makes installation quick, even for DIY projects.
  

7. Can I use these sheets in a shed or outbuilding?

Yes. Polystyrene insulation is ideal for sheds, summerhouses, garden rooms, workshops and garages. It helps retain heat and reduces condensation when installed correctly.

8. Are the sheets suitable for floors or ceilings?

Yes. EPS sheets can be used for floors, ceilings and lofts, provided they are fitted against a solid substrate or between joists.

9. Do I need a vapour barrier with EPS insulation?

In most indoor applications, a vapour control layer (VCL) is recommended to reduce moisture transfer. For sheds/outbuildings, usage depends on ventilation and lining type.

10. How do I fix the sheets in place?

You can install EPS using:

• 
  Adhesive foam or construction adhesive
  
• 
  Mechanical fixings
  
• 
  Timber battens
  
• 
  Stapling (for lining membrane layers)
  

11. Are these sheets safe to use indoors?

Yes. EPS insulation is non-toxic, inert and widely used in homes, schools and commercial buildings.

12. Do the sheets help reduce heating costs?

Yes — by improving the thermal envelope, EPS insulation helps retain warmth, reduce heat loss and increase overall energy efficiency.

13. Can I layer two sheets together for extra insulation?

Yes, many customers double-layer 25mm or 50mm sheets to achieve 75mm–100mm+ performance. Ensure joints are staggered for best results.

14. Do you deliver across the UK?

Yes. We deliver nationwide across the UK, with fast dispatch and protective packaging.