Flex-primer
Flex Primer. As a flexible additive for sandstone and grey floor grout. One bottle will mix with 20-25kg of grout when used on a flexible/suspended/heated subfloor.
CAN also be used as a primer for timber floors and MUST BE USED as a primer on calcium sulphate (non-cementicious or pumped) screeds. If in doubt always order at least one bottle.