Lightweight Concrete Information

Lightweight Roofing
Lightweight Roof
Lightweight Roof
Vermiculite concrete roof deck systems allow architects, engineers and contractors versatility in design, high performance and reasonable cost. These systems will use a lightweight concrete consisting of portland cement, water and vermiculite concrete aggregate. It is recommended that all vermiculite roof deck systems be applied by an applicator approved by Strong-Seal® Systems.

Advantages & Features

Lightweight
When compared with structural grade concrete, vermiculite concrete is 15% of the weight. This results in considerable savings from the footings through the structural steel.

Insulation
Vermiculite concrete has excellent insulating properties. Three inches of vermiculite concrete is equivalent to 1-1/2 inches of rigid board insulation layered over steel decks. One inch of vermiculite concrete is equal in insulating value to 20 inches of regular
Ease of Application
Vermiculite insulating concrete is easily placed by modern, specially designed pumping equipment. Up to 25,000 square feet can readily be placed in one day.

Fireproof
recognized nationwide by insurance companies, state rating bureaus and local building officials. Underwriters' Laboratories have assigned up to 4-Hour ratings to systems that employed vermiculite as one of the components.
Versatile
Vermiculite concrete can be applied over a variety of bases, allowing architects and engineers ample flexibility in their design criteria. The thickness of the concrete can be varied to permit necessary slope to drain.

Special Features

Reroofing
Slope-to-drain systems employing vermiculite concrete and polystyrene ventboard provide an economical solution to existing flat roofs with damage due to ponding of water.
Substrates
Vermiculite concrete is suitable for installation over most structurally sound roofing systems with structural decks of concrete, metal or wood.
Physical Properties
Mix Proportions by Volume
Cement Vermiculite Wet Density PCF Oven Dry Density PCF Comprehensive Strength 28 Days PSI "K" Factor
1 4 55-58 30-34 225-275 .79
1 5 50-54 26-30 175-225 .74
1 6 45-49 23-26 140-175 .70
1 7 43-45 21-23 125-140 .67
1 8 40-43 19-21 100-125 .64