Render Prime: Optimal Primer for Enhancing Adhesion on Porous Substrates - External Wall Primer

Render Prime is a waterborne primer, applied on dense substrates prior to the application of waterborne dispersion coatings.

Used as a post treatment after installation of Passive Purple®, Airtight White® & Passive Purple® External. The use of this exterior render primer will consolidate and close off difficult porous substrates like concrete bricks, calcium silicate stone and lime renders. The small molecules in it enter deeply into the substrate and once absorbed functions to consolidate as well as a primer. You then apply water dispersion coatings over the top.

Has much smaller molecular structure so it’s not to be used on render or porous concrete block, because it has no/little effect.

Used as a pre-treatment before installation of Passive Purple External. It’s micro emulsion, small molecular make up enters deeply into the substrate so it functions to consolidate as well as a primer. To be used on dense substrates: concrete, (old) lime, Render Prime is the choice for old render/old lime, because these surfaces need consolidation before applying a coating on it.

Due to the high vapour permeability of Render Prime it can accommodate subtle movements (without cracking). It sits on top of substrates and works in perfect unison with our air & vapour control membranes high tensile elongation values and is a perfect solution for older buildings that move a lot. 

Features and benefits:

• Specifically formulated to improve the adhesion of coatings on difficult substrates and reduce risk of surface defects.
• Application at temperatures of +5 °C and above.
• Shelf-life of 12 months.
• Supplied in 5 L can.
• Waterborne.