When a Layover Is Possible
Layovers are most often discussed when a low-slope commercial roof reaches the end of its service life. Rather than removing the existing membraneMaterial - A single-ply membrane is a roof covering that uses one continuous layer of material to waterproof low-slope roofs. More, a contractor may install a new roof systemRoof Types - A roof system (roof assembly) is the entire series of roofing layers and components above the roof deck that work together to weatherproof the building. More directly over the existing one.
Whether this approach is viable comes down to two factors: the condition of the existing roof and the number of roof layers already installed. If the substrate is wet or more than two roof layers are present, a layover is not possible.
When these conditions are favorable, a layover allows a new membrane to be installed with less disruption to the building and typically lower installation costs. The feasibility of a layover is usually confirmed through roof inspections and diagnostic work such as core samples.