• Brick, stone, concrete, and mortar are porous materials, and moisture is easily absorbed into these materials. A brick can absorb as much as 20% of its weight in water. Prolonged exposure to high amounts of water can soften and eventually weaken mortar and other masonry materials. There is evidence that water is being absorbed into your chimney exterior walls. Water in the masonry can cause deterioration over a period of time. Water leaching through the masonry walls can lead to water intrusion into the chimney or even into the home. Water that is in masonry can freeze in cold weather and cause damage to the structure. While it is important to prevent the excess absorption of water, masonry materials need to be able to breathe and let water vapor enter and exit the masonry. Some masonry sealants on the market seal the masonry too tightly. Brick, stone, concrete, and other masonry materials should be sealed with a proper masonry sealant. A proper sealant will allow water vapor to enter and exit the masonry while preventing the absorption of water droplets.

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