Waterproof plastering additive for sand and cement render.

Price excl. VAT
Price incl. VAT
(11 items in stock)

Renderproof Render Additive is a salt and water resistant admixture. Dilute it for use in sand and cement renders. Use the mixture to plaster walls after treating rising dampness.

What does a Render Additive do?

  • Moisture evaporates after rising damp treatments. A waterproofer helps to hold it back as the walls dry.
  • As water evaporates, salts remain. An inhibitor helps to stop salt transfer to the plaster surface.
  • A plasticiser improves the render's workability.

Use triple-action Renderproof Render Additive in plaster mixes. It removes the need for separate admixtures. Add one part of Renderproof to 24 parts water. Use the 25 litres of diluted fluid with 50 kg of cement in a 3 to 1 sand-to-cement mix. Use our lightweight Renovating Plaster if you need a less dense render coat. 

Delivery options are only available for delivery to mainland UK (excluding Scottish Highlands, Scottish Islands, Channel Islands, Isle Of Man Northern Ireland and Eire). Delivery to Scottish Highlands, Scottish Islands, Channel Islands, Isle Of Man, Northern Ireland and Eire are limited to 20kg and are available at a Premium rate. Please contact us on or via our help line if delivery is required outside these areas. Alternatively select ‘World-wide Delivery’ and a member of our sales staff will contact you regarding your options and costs.


We offer for the mainland UK , as standard, a FREE delivery service on all orders having a value greater than £200.00 (excluding VAT). For orders having a value less than £200.00 (excluding VAT) a carriage fee of £8.50 + VAT will be levied. Goods will be sent by a national carrier on their 1-2 working day standard service. Customers must understand that delays can always happen while their order is with the courier, for this reason we can not guarantee your order will be with you next day.

It is important that the customer ensures that all the delivery details are correct and that the customer or someone acting for the customer is able to sign for the delivery. Twistfix accept no liability for failed deliveries as a result of incorrect delivery details or the absence of any authorised signatory. Twistfix will attempt delivery to the recipient between the hours of between 8am and 6pm. If no one is available to receive the delivery an attempt may be made to leave the item with a neighbour. Alternatively the carrier may return the item to the sorting office and leave a calling card at the recipient's address to advise of the attempted delivery. It is the responsibility of the customer to arrange to collect the item from the depot or to arrange re-delivery with the carrier. Further information regarding Delivery can be read at our Terms & Conditions.


Items returned and received in their original condition and packaging within 14 days of delivery will be accepted for exchange or refund subject to a 20% restocking fee. You will be responsible for the shipping costs incurred in returning the goods and should ensure the items are adequately insured while in transit to us. You should email to request to return items.

Where the goods are being returned because they are faulty or are not the goods that were ordered then, subject to the goods being returned in re-saleable condition, Twistfix will refund the cost of return shipping. Further information regarding Returns can be read at our Terms & Conditions.