Question: how much pva to add to mortar?
Answer: Sand, Cement and PVA Mix To use in sand and cement, a mixture of 2 parts PVA to 1 part water is general. Tip the PVA in the water and mix as normal. PVA dries to a colourless finish and will not react with any other surface preparation or finish. Paint the surface with a coat of PVA before application of the mortar.