Inverted roof waterproofing systems
An inverted roof system is a flat roof build-up where the waterproofing membrane is installed beneath the thermal insulation, rather than above it.
This configuration offers enhanced protection for the membrane and is particularly suited to terraces, podium decks, green roofs, and ballasted roofs.
RENOLIT ALKORPLAN Classic
Cost-effective synthetic single ply membrane of plasticised PVC-P.
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Mechanically fastened system
| Perfectly suited for lightweight metal deck structures. |
| Mechanical resistance (woven polyester reinforcement). |
| UV and fire resistance. |
Ballasted system
| It can be totally recycled. |
| It has excellent dimensional stability (glass fleece reinforcing). |
| Simple and fast installation without glue or fasteners. |
Adhered system
| For concrete support. |
| For when the vapour control layer cannot be perforated. |
| Compatible with old bituminous membrane. |
Benefits of choosing our single ply membrane for inverted roof projects
Increased durability
Improved thermal performance
No condensation
Most used accessories for the installation of this product
RENOLIT ALKORPLAN Inverted roof FAQs
An inverted roof places the waterproofing membrane below the insulation, whereas in a warm roof, the membrane is installed above. This protects the membrane from UV exposure and mechanical damage.
Only closed-cell, water-resistant insulation such as extruded polystyrene (XPS) is suitable, as it can withstand prolonged exposure to moisture without losing thermal performance.
Yes. Inverted roofs provide a stable base for green roofs (vegetated systems) and blue roofs (rainwater retention systems), making them ideal for sustainable urban drainage strategies.
With quality materials and correct installation, inverted roofs can last 40 years or more, especially as the membrane is shielded from environmental stress.
