Thompson's Patio & Block Anti-Slip Additive is quick and easy to use, providing extra grip to patios and block paving. This Anti Slip Additive should be used in conjunction with your chosen finish of Thompson's Patio & Block Paving Seal, satin or wet Look (this SHOULD NOT be used with Natural Finish) Suitable for use on all treated patio and block paving including flag stones, granite, cast, limestone and sandstone. Preparation Prepare the surface as directed on the Patio & Block Paving Seal pack For Satin Finishes Apply two coats of Patio & Block Paving Seal prior to applying Anti Slip For Wet Look Finishes Apply one coat of Patio & Block Paving Seal prior to applying Anti Slip Make sure the seal is fully dry before continuing.