Karnak Karna-Flex is an elastomeric sealant for EPDM surfaces that cam repair and seal any splits, seams or leaks. Boasting high-adhesion and elasticity, the durable sealant is brush-applied to repair PVC roof membranes, TPO membranes and EPDM too. Suitable for use on plywood roof substrates and spray polyurethane foam, you will use around 1-2 litres per square metre, making this product very cost effective. Uses for this elastomeric sealant include for sealing metal roof seams, repairing PVC guttering and sealing around rooflights. Karna-Flex elastomeric sealant comes with a 10-year guarantee. Please note: Karna-Flex is not designed for use on asphalt surfaces and any TPO or PVC membranes must have been weathered for 4 years for this sealant to take effect. This sealant comes in a 10.5 litre tub.