Inverted Ballasted Roof

A ballasted roof means that the roof membrane is not anchored or adhered in any way to the decking material.

Inverted ballasted roof.

When the concept first came to the u s plenty of roofers scratched their heads and wondered how the roof stayed on without being anchored especially during high winds or storms. Firestone epdm ballasted system application. Adds a lot of weight to the roof system typically 10 15 pounds per square feet. Insulation boards are loose laid on top of the membrane and then weighted down with paving slabs or gravel ballast.

Benefits of inverted roofs. Roofs with pavers as ballast can be used as outdoor patios. Invented by dow in the late 1960 s an inverted roof system uses dupont styrofoam brand xps insulation to protect the membrane helping improve the performance and longevity of the entire roof system. Iko permatec is fully bonded to the structural deck and covered by insulation xps or modified eps which is covered by a separation layer and a ballast of stone pebbles or concrete pavers.

The iko permatec inverted ballasted roof provides a protected membrane system which usually incorporates insulation. The total system usually weighs between 100 to 145 kg m2. Ballast stone traps a lot of dirt making patching difficult. An inverted roof also known sometimes as a protected membrane or pmr roof uses the same materials as a conventional roof but places insulation on the top of the membrane.

Drawbacks of a ballasted roof system. Extremely difficult to find a leak in this system since the membrane is well hidden.