How to Apply OCR

There is a wide variety of one coat renders available on the market, often chosen by homeowners due to the fact that it is a cost-effective solution while being considerably better than sand and cement render.

We’ve recently started stocking EWI Pro’s EWI-265 OCR, which is a one-coat, cement-lime render, ideal for application using a spray machine. The product is a great solution for creating a smooth surface prior to applying masonry paint, so have a read about how to apply it!

OCR Installation Guide: Substrate Preparation

If the original substrate does not have a good key, we recommend using the EWI-310 Universal Primer, which contains quartz aggregate to provide a rough surface for the render to adhere to.

Once the substrate has been primed, it may need levelling. If it’s particularly uneven, we recommend the use of the EWI-269 Lightweight Basecoat, which can be applied up to 25mm thick in one pass. The product should be mixed with 5 litres of water per 25kg of dry mix. Once combined, the basecoat should be applied at the required thickness to level off the wall. We recommend embedding a layer of Fibreglass Mesh into the basecoat to ensure its stability. Leave to dry completely before applying any further materials.

Applying OCR

If the substrate doesn’t need levelling, you can apply OCR straight off. The bag needs to be mixed with 5.5 litres of water, and it should then be applied at a thickness of 5-15mm (usually this is dependent upon how even your substrate is). If you didn’t apply a levelling layer to begin with, you should embed mesh into the OCR instead.

Choosing your Decorative Finish

OCR is not through-coloured, so a decorative finish will need to be applied on top. Many people opt for a painted finish to achieve a smooth surface texture; we recommend the use of our EWI-005 Silicone Paint, which is a highly hydrophobic masonry paint. This particular paint repels water and is very breathable, so it’s a great choice for ensuring that the render is totally sealed in.

Silicone Paint can be tinted to create any colour, and we can even match to NCS and RAL colours.

Interested in OCR or have any questions? Our experienced Sales Team will be happy to assist with any enquiries you may have! Find our contact details here.





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