Using a decorative finish over existing render

Applying a decorative finish, including painting, over existing render is the preferred option when refreshing the appearance of existing render as opposed to removing the existing render (which is a large undertaking and may cause significant damage to the substrate) or rendering over existing render (which can cause a range of issues relating to the strength, bond and key of the existing render).

For sound, site-batched renders which were not manufactured by Weber, they should be checked first for suitability of condition and be free from anything which may impair adhesion of the new decorative finish.

Step-by-step guide

It is essential that when choosing to coat render with a decorative finish, including paint over render, that the existing render is free from loose or friable materials.

  1. Clean existing render

    It is important all dirt and organic growth is fully removed and cleaned as this can create a weak intermediate layer and affect the performance of the new decorative finish.

    Larger pieces of dirt and organic growth may be removed with a soft brush. Following this, a render biocide cleaner such as weber CL150 must be used to kill spores and prevent further growth.

    See our guide on cleaning render to find out how to do this.

  2. Apply primer

    Now the existing render is clean, prime with weber PR310 using a brush, roller or spray and allow to dry for 24 hours – drying time may vary depending on weather conditions.

    For product details or a more detailed application tutorial, please visit the weber PR310 product page.

  3. Apply decorative finish

    Once primer is fully dried, apply a decorative finish coating. Visit the links below for application instructions for each:

Contact us

If you would like additional information on using our range of decorative finishes onto existing render, please get in touch with our technical team:

Our technical team is available Monday to Friday, 8:30am until 5:00pm.

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