Inverted roof waterproofing system

A lasting roof starts with expert waterproofing

An inverted roof – also known as an upside-down roof – is designed with the waterproofing layer placed directly on the structural deck, beneath the thermal insulation. This configuration provides excellent thermal performance and protection for the membrane itself, but it also introduces unique challenges. Standing water, heavy ballast, and constant thermal movement put continuous stress on the waterproofing system. Without proper protection, even minor leaks can compromise insulation performance, damage the structure, and shorten the roof’s lifespan.

High-quality waterproofing is therefore critical. It forms the foundation of the roof’s durability — preventing moisture ingress, protecting the structure, and ensuring long-term performance. Whether on a residential building, a commercial complex, or an industrial facility, a reliable waterproofing membrane is essential to maintain comfort, safety, and energy efficiency over time.

That’s where Bitufa’s expertise makes the difference. Drawing on over 45 years of experience, we develop bituminous waterproofing systems that stand the test of time — proven to perform in demanding environments worldwide. Designed for use beneath insulation layers, our membranes maintain watertight integrity year after year, ensuring long-term protection with minimal upkeep.

What makes Bitufa waterproofing for inverted roofs unique?

Bitufa’s inverted roof systems are designed for exceptional durability and protection. Installed beneath the insulation, the waterproofing membrane is naturally shielded from UV exposure, mechanical stress, and extreme temperature changes. This not only extends its service life but also ensures consistent thermal performance across all seasons.

Our membranes resist root penetration, chemical exposure, and repeated freeze–thaw cycles, making them ideal for flat and green roof applications. With strong adhesion and flexibility, they provide secure waterproofing even at complex junctions and detailing points — areas where leaks most often occur. When combined with professional installation and effective drainage, Bitufa’s inverted roof systems deliver long-term watertightness, reduced maintenance, and lower lifecycle costs. They are trusted in residential, commercial, and industrial projects where durability and performance are paramount.

 

Flexobit: Reliable waterproofing that lasts

At the heart of Bitufa’s inverted roof solutions lies Flexobit — a 5 mm thick, homogeneous, non-reinforced SBS waterproofing membrane that redefines durability and performance. Its reinforcement-free design allows the membrane to conform perfectly to any surface, eliminating cutting and overlaps while significantly reducing installation time.

Made from SBS polymer-modified bitumen, Flexobit offers superior flexibility and long-term elasticity, ensuring the system remains watertight even under continuous mechanical load and thermal cycling. Its self-healing properties seal minor punctures or surface damage, maintaining protection year after year.

 

MORE ABOUT FLEXOBIT

Bitufa Waterproofing Solutions

Key Benefits:

    • Seamless, self-healing membranes

    • Extreme elongation and flexibility

    • Durable and long-lasting

    • Critical area protection

    • Versatile installation

    • Proven experience, over 45 years

Applications:

    • Inverted roofs
    • Basement walls and floors
    • Retaining structures

Atlantis Royal Towers &
Atlantis Water Park

Consultant: Norr Engineers Consultants

Contractor: Al Naboodah Laing O’Rourke

System: Flexobit Tanking System

Quantity: 130,000 m2

Client: Kezner International