Granirapid is absolutely essential when working with absorbent, water or moisure sensitive substrates. This waterless systems can eleminate troubled installation issues associated with porous materials and staining. It is always advised to pre-seal the surface with our Lithofin PRO pre-sealer when working with extremely porous materials and to ideally use Granirapid adhesives for installation. Granirapid's quick drying time allows grouting in 2 -3 hours. A clean and successful installation job each time.