How to prepare surfaces for bonding
Published: 27 May 2021
Preparing surfaces correctly before applying product is vital to ensure full bond of the roofing adhesive or coating.
Surfaces must be clean, dry and free from frost and contamination. Adhesives will stick to anything they are laid on. If there is any contamination, such as moss, this will affect the bond and the integrity of the whole system will be compromised.
Higher levels of humidity in warmer months could also result in condensation appearing on the surface of the substrate. This can act as a barrier for adhesion. Apollo recommends not applying the adhesive when the relative humidity is 80% or higher. A thermo-hygrometer can be used to measure the relative humidity.
Should I use a primer to prepare surfaces?
Different substrates and applications will present different problems; however, primers can be used to seal a surface and help adhesion. Primers come in a variety of different forms, the type needed will depend on the substrate and the type of coating being applied.
Primers are often included as part of the system warranty because they have been tested to a high standard, protecting the longevity of the roof. Read more about the importance of a primer here.