VPI Base Coats For Painted Substrates

Sound existing paintwork does not always need to be removed before a façade is renovated. Where the coating remains securely bonded and is compatible with the proposed system, VPI RenoPass Inter can create a new reinforced base for a suitable decorative finish.

Paint type and condition must be established before work begins. These products are not recommended over oil-based paint, while loose, flaking or poorly bonded coatings must be removed.

Products in This Range

• VPI RenoPass Inter – A thin, fibre-reinforced renovation base coat developed for old painted masonry, existing painted renders, organic decorative coatings and hydraulic renders.
• VPI Reinforcing Mesh – An alkali-resistant mesh used with compatible cement, lime and polymer-modified render systems to improve resistance to cracking.

Suitable Renovation Backgrounds

Subject to inspection and technical specification, RenoPass Inter may be used over:

• Sound existing masonry paint
• Old organic decorative render
• Existing hydraulic render
• Selected small-format mosaic finishes
• Suitable thin concrete façade panels
• Approved existing external wall insulation systems

It should not be assumed that every painted surface is suitable. The retained coating must be capable of supporting the weight and stresses of the new render system.

Assessing Existing Paintwork

Before application, check the paint for flaking, blistering, chalking and loss of adhesion. The underlying render or masonry must also be stable and free from active cracking, trapped moisture or structural movement.

Complete appropriate adhesion tests in representative areas. Remove loose material and clean away dirt, algae, grease and other contamination. Defects should be repaired before the renovation base coat is applied.

Oil-based paints and coatings that cannot provide reliable adhesion should be removed rather than covered.

Application and Reinforcement

RenoPass Inter may be applied manually or using suitable spray equipment. Typical application thickness is approximately 3–5mm over smooth surfaces and 5–7mm over rough backgrounds, although the precise requirement will depend on the substrate and project specification.

Where mesh reinforcement is specified, it should be completely embedded within the wet base coat with suitable overlaps. Additional reinforcement may be required around openings, cracks and changes in substrate.

Always follow current VPI technical guidance for adhesion testing, preparation, application thickness, reinforcement, drying time and compatible decorative finishes.