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Waterproofing: the finish coat, never the fix

Let us be straight about what a sealer does and does not do. A breathable water repellent slows how fast sound masonry absorbs rain. It does not close a cracked crown, does not replace failed flashing, and does not rescue washed-out joints. Sprayed over active failures, sealer mostly hides the evidence while the inside of the stack keeps getting wet. Applied after repairs on a sound chimney, it meaningfully extends everything you paid for.

Breathable matters in this climate

The product class we use is siloxane-based and vapor-permeable: liquid water beads off the surface while moisture already inside the masonry escapes as vapor. Film-forming sealers and paint do the opposite, sealing existing moisture in, and trapped moisture is exactly what drives spalling here. On chimneys that spend seven months a year damp, the breathable distinction is the whole game.

Moss, the local specialty

Moss holds water against masonry like a wet sponge zip-tied to your chimney, and shaded north faces in University Place grow it well. Waterproofing visits include moss treatment and removal from the worked surfaces, because sealing over a moss mat wastes the product and leaves the sponge in place.

Common questions