Your shower should be available for use in 48 – 72 hours when cured at 70°F (21°C). However, LATICRETE SpectraLOCK PRO Premium Grout and LATICRETE SpectraLOCK PRO Grout do not reach full stain resistance for 7 days at 70°F (21°C) so please use caution when using heavily dyed cleansing products (e.g. shampoo, soap, tile/grout cleaners, etc…).