Why roof insulation is no longer optional
Electricity tariffs and summer peak cooling loads push owners to insulate concrete roofs that were historically bare slab plus waterproofing. Uninsulated decks radiate heat into top-floor flats, hospital wards, and classroom blocks. Extruded polystyrene (XPS) boards and polyurethane foam (PUF)—rigid boards or spray-applied—raise thermal resistance without always adding structural load like a second slab.
Petroseal Enterprises coordinates waterproofing and insulation as one technical relationship: PetroGrip membranes above, thermal layers below or in the middle of the build-up as designed. Thermal products are manufactured and supplied through Green Insulation Private Limited, our sister concern.
Green Insulation XPS foam boards
Green Insulation XPS extruded polystyrene foam boards feature a closed-cell structure, low moisture absorption, and high compressive strength for concrete roofs, walls, basements, and cold storage. Standard sheet sizes include 4×8 ft with thicknesses at 1", 2", 3", and 4 inches; compressive strength grades such as 250, 350, and 500 kPa match light pedestrian roofs to heavier service loads.
A typical sequence: insulation, separation or protection layer if specified, then PetroGrip APP cap sheet with aluminum surfacing. In Punjab and Sindh heat, two to three inches of XPS is a common consultant starting point before tuning for target U-value and budget.
Polyurethane foam (PUF): boards and spray
Green Insulation also supplies polyurethane foam insulation—rigid PUF boards and spray-applied systems. PUF delivers high R-value per inch, helping where parapet height limits total build-up thickness. Spray PUF fills corrugated profiles on industrial sheds.
PUF is thermal insulation only—it is not a waterproofing replacement. Pair PUF with PetroGrip waterproofing above, closed-cell grades for high-moisture roofs, and confirm fire and building-code requirements with the project consultant.
XPS versus PUF: how to choose
| Factor | XPS boards | PUF boards / spray |
|---|---|---|
| Install familiarity | High—staggered boards, taped joints | Boards: high; spray: needs skilled crew |
| R-value per inch | Good | Higher—thinner assemblies possible |
| Compressive strength | Published grades, walkable with care | Board grades vary; spray follows profile |
| Best fit | Flat concrete roofs, cold rooms | Metal deck, tight parapet, irregular geometry |
Failure modes to avoid
- Wrong sequence causing condensation or crushed insulation
- Ponding water under insulation from poor falls—fix drainage first
- UV exposure and foot traffic on boards before membrane is complete
- Waterlogged XPS stored on site—thermal performance drops
Nationwide supply
Contractors get datasheets for both brands, coordinated deliveries from Lahore, and one phone line for technical questions: 0321 8489737. Specify insulation thickness, compressive grade, membrane, and surfacing in one package—XPS and PUF cut cooling loads; PetroGrip keeps the deck dry.
Download datasheets at petrosealenterprises.com including Green Insulation XPS board specifications.