The product works best when applied to a clean dry surface, free from mould or dirt. We recommend cleaning with household bleach or similar, then rinsing and allowing to dry before applying the Mould Repellent.
If there is mould in the acrylic sealant, this needs to be cut out and sealed.
New grouting should be allowed to cure for at least 30 days before application. Grout needs to remain slightly moist while it cures to prevent the creation of dark patches. If you use Mould Repellent too soon you are trapping moisture in the grouting . This may cause structural weaknesses in the grout and cause chunks to fall out. You may also start to see mould forming around your tiles as added moisture means greater chance of microbial and bacterial growth.