Poor Alkali Resistance
Manifestations
- Paint film on fresh masonry undergoes a loss of color and overall deterioration.
- Causes
- Fresh masonry may contain lime, a very alkaline component.
- Until the new masonry has “cured” for a year it can have a detrimental effect on paint film.
- Curing is accomplished by the masonry reacting with carbon dioxide in the air, thereby dissipating its natural alkalinity.
- Solutions
- Prior to painting new masonry, allow it to cure for a minimum of 30 days. The ideal curing time is one year.
- When that is not possible, coat the masonry with a high-quality, sealer or latex primer that is alkali resistant.
- Then apply a top quality, all acrylic latex exterior paint.
- This type of paint contains an acrylic binder that is resistant to the detrimental effects of alkali on fresh masonry.