EPS (expanded polystyrene), widely called "thermopore" in Pakistan, is a light, rigid white foam board full of trapped air. That trapped air slows heat flow, which is why EPS is one of the most common roof insulation materials in Lahore. It is also used in walls, false ceilings, cold rooms and packaging.
Types and specifications
| Specification | What it means | Why it matters |
|---|---|---|
| Thickness | Board thickness, often quoted in inches or mm | Thicker boards insulate more |
| Density | Mass per volume of foam (kg/m³) | Higher density is stiffer and more resistant to crushing under screed and foot traffic |
| Fire-retardant (FR) grade | Board made with flame-retardant additive | Safer; ask for it in buildings |
| Board size | Length × width of each sheet | Affects cutting waste and handling |
| Edge type | Plain or shiplap/tongue-and-groove | Interlocking edges reduce heat leaks at joints |
| Facing | Plain or with foil/sheet facing | Facings can add reflection or protection |
Ask the supplier for the density and grade in writing. Two boards of the same thickness can perform very differently.
What it is used for
| Use | How it is installed |
|---|---|
| Flat roofs | Over the waterproofing layer, under a protective screed, mud layer or tiles |
| Walls | In cavity walls or fixed to wall faces under plaster or cladding |
| False ceilings | Above ceiling boards in top-floor rooms |
| Cold rooms and stores | As part of insulated panels |
| Under floors | Over a slab under screed |
EPS should not be left exposed to sunlight on a roof; UV light degrades it. It also softens with some solvents, so check adhesives and coatings are compatible.
Quality checks on delivery
- Measure thickness at several points on a few sheets.
- Count sheets against the invoice.
- Check density claim. Weigh a full sheet and divide by its volume to get approximate density; compare with what was quoted.
- Edges and corners. They should be firm, not crumbly.
- Fire-retardant grade. Confirm on the label or invoice.
- Bead bonding. Break a small offcut: well-made board breaks through the beads, poor board crumbles into loose beads.
How much you need
Roof area ÷ area of one sheet = number of sheets, plus a cutting allowance for drains, parapets and corners. If you lay two layers with staggered joints, double it. Your contractor can give an exact count after measuring.
Bulk-buying tips
- Deliver close to installation; boards are light and blow away in wind.
- Store flat, under cover, off the ground, away from flames, cigarettes and solvents.
- Plan unloading to avoid broken corners.
- Ask for shiplap edges on roofs where available.
- Keep the invoice listing thickness, density and grade.
What affects the price
- Thickness.
- Density (higher density uses more material).
- Fire-retardant grade.
- Edge profile and facings.
- Order size and sheet size.
- Delivery, since EPS is bulky and fills a truck by volume, not weight.
We did not find dated, sourced Lahore rates, so get written quotes for the same thickness, density and grade.
FAQs
What thickness of thermopore is best for a roof? Thicker boards insulate better but cost more and add height to the roof build-up. Ask your contractor or supplier to recommend a thickness for your roof and budget.
Is thermopore waterproof? EPS absorbs little water, but it is not a waterproofing layer. Use a membrane or coating under or over it as designed.
Can I walk on EPS on the roof? Not directly for long. It needs a protective screed or tiles on top.
Is thermopore a fire risk? EPS can burn. Ask for fire-retardant grade and keep it covered by screed, plaster or other protection.
How long does EPS insulation last? When protected from sunlight and mechanical damage, it can last for many years. Exposed or crushed boards lose performance faster.
Sources
No external figures are used on this page. Specifications and checks reflect common practice; get written quotes and data sheets from suppliers.