Chimney waterproofing applies a vapor-permeable water repellent to brick and mortar so rain can't soak in, while moisture inside can still escape. It works together with a sealed crown, a cap and tight flashing — together they stop almost every chimney leak.
Signs you need waterproofing
- Water stains on ceilings or walls near the chimney
- Damp or musty smell from the fireplace
- White staining (efflorescence) on the brick
- Rusty damper or firebox components
- Peeling paint or wallpaper next to the chimney
Our process
- Find the leak. We test the crown, cap, flashing and masonry to find exactly where water is entering.
- Repair first. Cracked mortar, failed flashing and crown cracks are fixed before any sealer goes on.
- Apply water repellent. A breathable, masonry-specific repellent is applied to the clean, dry brick.
Why not just paint or seal it?
Regular paint and non-breathable sealers trap moisture inside the brick. When that water freezes, it causes the face of the brick to pop off. Masonry water repellents are vapor-permeable: they keep liquid water out and let water vapor escape.
Flashing: the #1 leak source
Flashing is the metal seal where the chimney meets the roof. Caulked-only or poorly installed flashing fails quickly. Proper step and counter flashing, cut into the mortar joints, is the long-term fix.
Frequently asked questions
How long does chimney waterproofing last?
Quality masonry water repellents generally last several years, depending on exposure. We'll tell you when it's time to reapply during your yearly inspection.
My chimney only leaks during heavy rain — why?
That usually points to flashing or crown problems that only let water in when the roof is flooded with runoff. We find and fix the exact entry point.
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Waterproofing near you
Philadelphia, PA · Bucks County, PA · Montgomery County, PA · Delaware County, PA · Chester County, PA · Lehigh Valley, PA · Cherry Hill, NJ · Burlington County, NJ · Gloucester County, NJ · Trenton & Princeton, NJ · Edison & Middlesex County, NJ · Monmouth County, NJ · Toms River & Ocean County, NJ · Bergen County, NJ · Wilmington, DE · Newark & Middletown, DE · Dover, DE · Staten Island, NY · Nassau County, NY · Suffolk County, NY · Westchester County, NY · Fairfield County, CT · New Haven, CT · Hartford, CT