It is not recommended to apply Impermax Aqua membrane directly on surfaces. In case of damp surfaces, or if there is suspicion of humidity, it is imperative to pre-treat the area with Impermax Humidity Primer.

Humidity creates two important problems in treatments:

• Lack of adhesion.
• The appearance of blisters in the surface of the finished membrane (due to the vapour pressure generated as the area is exposed to sunlight, which creates bubbles and deforms the elastic material).

The quantity of Impermax Humidity Primer should be approx., 200 to 300 grams per square meter.

It is recommended to use Humidity Primer in most situations.