Chimney Waterproofing — Greater Seattle, WA

The Right Sealer Makes a Difference

Washington gets 38+ inches of rain a year. Masonry is porous. Water is the enemy. Applying a penetrating waterproofer to your chimney is one of the best investments you can make — it stops moisture intrusion without trapping vapor inside the masonry. Up to 10 years of protection per application.

We use penetrating chimney sealing products (ChimneySaver or equivalent) designed specifically for masonry. The key word is vapor-permeable — the sealer repels liquid water from the outside, but allows water vapor already inside the masonry to escape. That's important. A film-forming sealer (like paint or regular masonry sealer) can trap moisture and cause the exact damage you're trying to prevent.

Waterproofing is most effective when done after any needed masonry repairs — repointing, crown work, or flashing — are already complete. We'll sequence the work correctly so the sealer protects fully from day one.

The Rain Factor

Why WA Chimneys Need Waterproofing

Brick and mortar are porous materials. Over time, they absorb water from rain and condensation. In Western Washington's wet climate, that means your chimney is absorbing moisture for months at a time. When temperatures drop, trapped water expands as it freezes — and that expansion forces the masonry apart from the inside.

It's a slow process, but it compounds every year. Waterproofing breaks that cycle. It's cheaper and simpler than any of the repairs it prevents.

Wondering what it costs? See our chimney waterproofing cost guide for a full pricing breakdown.