Self-adhesive modified bituminous Waterproofing Membrane Installation
Consider several factors when installing a self-adhesive membrane system.It is imperative to refer to the manufacturer’s application guidelines prior to specifying or installing any specific product. During installation, the temperatures of the air, product, and substrate should meet or exceed the minimum application temperature as recommended by the manufacturer. Generally, the minimum temperature range for application is between 40-50°F; however, it is advisable to consult the specific manufacturer for guidance on material storage and handling in colder conditions. Self-adhesive products should only be applied to a suitable substrate as defined by the product manufacturer. The substrate must be devoid of dust, dirt, oils, moisture, or any debris that could hinder proper adhesion.
Manufacturers may require priming the substrate before applying the membrane to improve adhesion. Apply primers with a brush, roller, or spray, and always confirm with the manufacturer regarding the primer type, application rate, and drying time. Exercise caution with solvent-based primers, as they can damage the self-adhesive membrane and roofing system if the solvent hasn’t fully evaporated before installation.
In contrast to other installation techniques for modified bitumen membranes, there is no liquid bituminous layer to address surface irregularities. Therefore, meticulous application is crucial, particularly at overlaps and T-joints. Typically, applying pressure to the sheet with a heavy roller is necessary. End laps on mineral-surfaced self-adhesive sheets may require heat welding or sealing with compatible roofing mastics as specified by the manufacturer. When using solvent-based mastic, it is important to adhere to the manufacturer’s recommended application rates and other precautions to avoid solvent-induced damage to the membrane.
For different grades of self-adhesive products and/or primers available for cold weather applications, it is advisable to consult the manufacturer’s written instructions for appropriate product selection.