ChimneySaver Water-Base Water Repellent has been in circulation by professionals for almost 20 years. This unique repellent is vapor permeable so it will not trap water vapors in the brick. Water repellents that trap the vapors in the brick actually cause spalling rather than preventing it. The Water-Base formula from ChimneySaver is specially for chimneys without treatment of another waterproofing product. If you have used a water repellent previously on your chimney, we recommend using the Solvent-Base water repellent.
It is important to remember there is always a certain, small percentage of moisture present in masonry surfaces or concrete. Film-forming sealers use silicone to coat the brick complete. This traps those vapors inside and catalyzing the rate at which brick spall and crack. This way the vapors cannot escape. This is the opposite effect of what a protective water repellent should do. Film forming water repellents will contribute to the rate at which the brick or concrete on your chimney or other masonry project deteriorates and heighten freeze-thaw damage.
In contrast to these film-formers is the ChimneySaver Water Repellent products. Both the Water-Base and the Solvent-Base make it possible for vapors to escape, preventing the deterioration of the masonry surface. Per gallon, the ChimneySaver Water-Base Water Repellent covers between 90 and 150 sq. ft. depending on the thickness of each coat, and it is available in 3, 5, 30, and 55 gallon containers. When applying this product it is important to make sure that the temperature outside is above 40 degrees Fahrenheit so that it can cure properly, and you must allow six hours of drying time before a rainfall even though the product itself has a dry time of one to two hours. Very cold temperatures will reduce the efficiency of the stain. It is recommended to apply using a pump-sprayer, and soap and water is appropriate for clean up.