Poor alkali resistance
Poor alkali resistance is the loss of colour and overall deterioration of paint film on fresh masonry.
Possible Cause
Poor alkali resistance is the loss of colour and overall deterioration of paint film on fresh masonry.
It occurs when oil-based paint is applied to new masonry that has not fully cured (at least one year). Fresh masonry contains lime and cement, which are very alkaline. Until the lime has a chance to react with carbon dioxide from the air, the alkalinity of the masonry remains so high that it can compromise of the paint film performance.
Solution
Always allow fresh masonry surfaces to cure for a minimum of 30 days, ideally for a full year, before painting. If this is not possible, apply a quality, alkali-resistant sealer or water-based primer. Using Dulux 1 Step Acrylic Primer, Sealer and Undercoat followed by Dulux Weathershield is recommended.
Help & Advice
Make confident decisions about your project needs with support from our wide network of painters or speak to one of our Help & Advice consultants now.
Help & Advice
Want to change but don’t know where to start? Dulux Help & Advice are expert consultants who can help you with colour advice, product selection and application, everything you need for your next paint project.
Contact Help & Advice-->