Cleaning Thermoplastic Membrane

It is critical to keep membrane roofing clean to maximize service life and heat reflective properties. Periodic inspection and maintenence is also typically required by roofing system manufacturers to keep roofing warranties in full force and effect. Although all building owners should establish a periodic roof inspection program, inspection and maintenance of any roof should be undertaken only by qualified persons who are familiar with safe roofing practices, including all applicable occupational, health and safety regulations relating to the roofing and construction industries.
Modern roofing systems contain a wide variety of components and installation techniques. All roof inspections should be conducted by a licensed roofing contractor or similar roofing professional.

Typically, two inspections should be conducted each year, one in the spring and one in the late fall.

1. Ensure that the existing area to which new Thermoplastic membrane is to be mated is clean, smooth, and free of all contaminants.
2. Thoroughly clean this area with detergent and water. It is recommended that a water-soluble granular cleaner be used such as T-M-T brand, which is manufactured by the U.S. Borax Company. Liquid cleaners tend to leave a film residue that can interfere with heat-weld quality.
3. It is recommended that a polypropylene scouring pad be used for maximum cleaning. This is the type manufactured by 3M. Coupled with the granular detergent it allows for enough abrasive action to thoroughly clean the sheet without causing damage to it.

 

NOTE: DO NOT USE STEEL WIRE BRUSHES UNDER ANY CIRCUMSTANCES.

1. It is imperative that the area be thoroughly rinsed several times to remove all detergent and contaminants before heat welding. Further, the area must be allowed to dry completely before continuing. If blisters form upon heat welding, the area has not been allowed to dry sufficiently and heat welding should discontinue.
2. After allowing to dry sufficiently, the heat-welding areas on the existing membrane shall be cleaned a second time with Denatured Alcohol and clean cotton rags to remove all surface impediments and eliminate any surface curing which may have occurred.

 

THOROUGH CLEANING WITH DENATURED ALCOHOL SOLVENT IS THE MOST CRITICAL PROCEDURE TO ENSURE THE PERFORMANCE OF THE NEW TO EXISTING     MEMBRANE HEAT-WELD.

1. All heat welding shall be in accordance with Firestone Thermoplastic details and specifications as published. Keep in mind that the existing sheet is aged, which may call for more allowance. Care should be taken not to overheat and scorch either membrane.
2. Upon completion, allow newly welded seams to cool.

IMPORTANT: ALL WELDS MUST BE THOROUGHLY PROBED AND CHECKED FOR COMPLETE INTEGRITY AND REWELDED OR STRIPPED IN AS REQUIRED.

Originally published in Firestone Building Products Roof Inspection, Maintenance and Repair Guide. Texas Fifth Wall Roofing is a certified Firestone partner.