Image of the Boston skyline
Billy Sweet Chimney Sweep Logo

boston call button

North Shore Call Button

Portland Maine Call Button

Click to see review places online

Home » Chimney Services » Chimney Leaks » Waterproofing

Chimney Waterproofing

Chimneys are made of porous materials, and over time, as water seeps into brick and mortar, that masonry can start to deteriorate, causing leaks and leading toward larger problems. That deterioration is only made worse with the changing seasons, as water that’s trapped in the masonry expands and contracts as it freezes and melts.

Waterproofing your chimney is a great way to fight off encroaching water, and it’s a worthwhile value to homeowners since it’s helping prevent big, costly deterioration that can come about otherwise.

Years ago, this preventative measure wasn’t an option, but today, we can extend the life and beauty of your chimney by applying a high-quality waterproof sealant that effectively blocks out water but still allows your chimney’s masonry to function as it should. If your chimney is 15 years old or older, we highly recommend applying a waterproofing sealant.

Waterproofing a Chimney Isn’t Simple

Waterproofing a chimney isn’t as simple as just sealing the outside, since the brick and stone needs to remain permeable, letting small particles and gases move from the inside of the chimney to the outside. Just applying paint to the outside of a chimney might help keep water away, but it wouldn’t allow the chimney to properly expel harmful gases. Current waterproofing products solve this problem, stopping water from getting through but allowing the bricks and stone to “breathe.”

This process will protect your masonry and allow it to function properly, so waterproofing your chimney can help extend the life of the chimney and help you avoid water issues for years to come.

Since your happiness is our priority, we also offer FREE Waterproofing on exterior masonry repair.

Other Preventative Measures

Waterproofing is just one preventative measure that can help keep water from damaging your chimney and your home. Other measures to consider:

  • Is your chimney cap damaged or missing? A cap is a simple and effective barrier that keeps rain from entering your chimney, so if it’s not working properly — or it’s not there at all — consider having a certified Billy Sweet Chimney Sweep technician inspect, repair and/or install one.
  • Is your chimney damper working correctly? The damper closes off the flue when the chimney isn’t in use, and it also keeps water from entering the home. If it’s not functioning properly, you might want to repair or replace it.
  • Do you have cracks or spalling (flaking and crumbling masonry) on your chimney crown? Your crown is there to help keep water away from the masonry, and cracks and spalling commonly lead to leaks. Have a Billy Sweet Chimney Sweep technician inspect and repair any crown issues as soon as possible.
  • Is there corrosion, loose caulk or holes in your chimney flashing? The flashing protects your chimney where it and roof line meet, and it’s an important line of defense against water. Call us to inspect and repair or replace if your flashing is showing signs of wear.

If you have any concerns about water getting into your chimney — or want to explore preventative measures to make sure it doesn’t happen — call Billy Sweet Chimney Sweep today!


Problems with your chimney flashing could be contributing to chimney leaks, so have it checked out right away.

No contact service calls

make an appointment online

schedule button

Check Out Our Financing With Enerbank

Enerbank Logo

Certifications & Associations

NCSG Member

CSIA Certified

don't be scammedF.I.R.E. Certified Inspector

Charities We Support

sweep away cancerdonate button

Warrior Horse logo

donate warrior horse


Follow Us

Facebook profile



We Are Proud Dealers Of

Regency Fire Logo