Roof Insulation
XPS above the membrane in the inverted warm-roof build-up — insulation that shields the waterproofing while it insulates the building.
One System, Built to Work Together.
In an inverted roof the insulation sits on top of the waterproofing, shielding the membrane from sun and temperature swings. The boards live outdoors, wet and loaded — a role XPS was made for.
Insutech XPS boards lay loose over the finished membrane under a filter layer and ballast, delivering the U-value while doubling the life of the waterproofing beneath.
- Inverted flat roofs
- Ballasted and paved roofs
- Roof terraces over insulation
- Plant deck areas
- Refurbishment over sound membranes
Layer by Layer.
- 01
Roof Deck
The structural deck, screeded to falls toward the outlets.
- 02
Waterproofing Membrane
The membrane goes down first — warm and protected beneath everything above.
- 03
XPS Insulation Boards
Moisture-proof boards laid loose over the membrane, joints tight.
- 04
Filter Layer
A fleece keeps fines out while letting rainwater drain through.
- 05
Ballast / Paving
Gravel or pavers hold the build-up down and finish the roof.
01Protects the Membrane
Insulation over the waterproofing shields it from UV and thermal shock — the membrane lasts far longer.
02Performs Wet
Closed-cell XPS keeps insulating in an exposed, rain-washed build-up.
03Walkable Build-Up
High-strength boards under pavers turn the roof into usable space.
04Simple to Re-Roof
Loose-laid layers lift and relay for inspection or refurbishment.
Common questions about this system.
Where is the Roof Insulation system used?
It is typically used for inverted flat roofs, ballasted and paved roofs, roof terraces over insulation, plant deck areas and refurbishment over sound membranes.
Which Insutech products are used for roof insulation?
The recommended system is built with Insu Foam, Iso Foam, Blue Foam and Insuboard Protection Board — full details for each are on the recommended products cards on this page.
How is the system installed?
The system is installed in 5 stages: roof Deck, waterproofing Membrane, XPS Insulation Boards, filter Layer and ballast / Paving. The system build-up section on this page illustrates the full sequence.
What are the main advantages of the roof insulation system?
The key advantages are protects the Membrane, performs Wet and walkable Build-Up — each is explained in the Key Benefits section on this page.