Which material would you be least likely to see being used as a roof deck.
Which of following is a function of the roof ballast.
Because the ballast stones are loose laid and not embedded into a layer of tar asphalt the gravel is easy to move when conducting repairs or maintenance.
It is however ballasted generally with gravel.
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.
Decking materials performance requirements.
Built up roofing system in roofing applications ballast can perform all of the following functions except contribute to air circulation under the roof membrane.
Roof membrane roof ballast if needed drainage flashing.
Despite the positive qualities associated with a ballasted roof system there are some challenges.
Ballast also protects against hail and from foot traffic during repair or maintenance work.
The ballast is used to keep the roofing system cool and of out of the sun s harmful rays thus keeping energy costs down.
Although single ply roofs inherently have sun protective qualities ballast provides an extra layer of protection from uv rays.
The gravel top coat is also extremely resilient to heavy foot traffic and high wind scenarios.
A ballasted roof means that the roof membrane is not anchored or adhered in any way to the decking material.