THERMOFLEX PRIMER is a solvent based bitumen primer with excellent penetrative and adhesive properties. THERMOFLEX PRIMER has two main areas of application. The first is as a primer for Bitumen “torch on” membranes on porous surfaces as well as corrosion protection and adhesion enhancement on metal roofs prior to the application of bitumen aluminium coatings. THERMOFLEX PRIMER is available in 25L and 5L containers.

Physical Properties

Colour: Black
Application: Brush, roller or spray
Coverage: 4-5m2/L porous surfaces, 8m2/L smooth surfaces
Total Solids: +/- 40%
Specific Gravity: +/- .90
Viscosity: Low viscosity liquid
Drying Time: 2 hours touch dry, 6 hours fully dry.
Cleaning: Mineral Turpentine      
Flammability: Flammable

Surface preparation

All forms of surface contamination must be removed to ensure a smooth surface, free of moisture and any loose material, or any other barrier to adhesion. 
Technical assistance and applicator training are freely available to all approved users.


Ensure THERMOFLEX PRIMER is thoroughly stirred before and during application, using a flat paddle.
THERMOFLEX PRIMER may be applied by means of brush, roller or spray. Ensure to apply at the recommended coverage rate, over application can lead to slower drying times as well as subsequent solvent entrapment, creating bubbles underneath bitumen “torch on” membranes.

During application strict fire precautions must be observed. Extreme caution must be followed if applying THERMOFLEX PRIMER near any air conditioning units or any other form of ducting. Fumes will easily build up causing health and fire risks in all areas serviced by the ducting.

6 hours curing time is required before over coating or applying “torch on” membranes
Do not apply onto wet surfaces.
Do not apply if rain is imminent
Clean up with mineral turpentine.

Technical assistance and applicator training are freely available to all approved users.

PDF Thermoflex Primer