You may take your chimney for granted, but it puts up with a lot. Chimneys always extend above the roofline, which means they are exposed to wind and rain even if it’s on the leeward side of the house. Waterproofing your chimney is essential to protecting both it and your home.

If water works its way into your chimney structure and deteriorates it, your home will eventually sustain water damage and possibly a loss of structural integrity. The freezing and thawing cycles of Nashville area winters combined with water penetration will shift and crack even the best masonry. Waterproofing your chimney now can prevent spalling, scaling, crumbling, and the eventual leaks that follow.

Chimney and Masonry Outfitters (CMO) of Nashville, your local resource for annual chimney sweeps, masonry construction, and chimney repair, is here to help. Whether you want to protect your brand new chimney from any future damage, or if you need repairs or reconstruction before waterproofing, we do it all.

Our company utilizes ChimneySaver brand waterproofing products. Tested to ASTM standards, ChimneySaver waterproofers reduce water penetration by 96.9%, yet still remains 100% breathable, allowing vapor to escape from the inside. It has been used by industry professionals for over 20 years and has stood the test of time. 

Waterproofing or Sealing?

A sealant tries to put a film of material on the outside surface of the structure, creating a physical barrier meant to keep water and other liquids firmly on the outside. However, this barrier will also trap water vapors behind the barrier, whether it was there before the sealant was applied, or works its way in from somewhere higher up. 

Chimney crowns are especially vulnerable to water entry, since it is a horizontal surface completely exposed to the elements. If a chimney crown was not properly installed, or the joints between the chimney cap and crown were not aligned or sealed properly, water has already worked its way inside your chimney masonry. This is where a sealant such as CrownSeal is useful, because you want to create a barrier against the rain and snow that will bombard the top of the chimney.

Types of Chimney 

Each kind of chimney design will require a slightly different approach when it comes to waterproofing. Depending on the materials used in its construction, it may need more coats of the same sealant, or a different sealant altogether. Most chimneys are built of either brick and mortar, or concrete blocks. 

Brick Chimneys

Less porous than concrete blocks, brick-and-mortar chimneys can still absorb a fair bit of water. This excess moisture, especially when combined with freezing, can loosen the mortar and compromise the structural integrity of your chimney. 

ChimneySaver has products designed specifically for this application, which successfully bonds to both the bricks and the mortar joints between them to protect your chimney from the elements. It won’t change the look or color of your chimney, and doesn’t create a surface barrier that can wear off or break down. 

This waterproofing formula works by repelling water, not by locking it out. It is mildew and fungus resistant, protects against staining, and has no glossy shine to it. 

Concrete Block Chimneys

With larger pores than brick, a masonry chimney will absorb more moisture. We use a different ChimneySaver product on block chimneys than on brick. This high-performance combination of silane/siloxane and acrylic elastomers penetrates the surface to bond with the minerals in the block and form a strong water-repellent coating. 

Fully breathable and 100% vapor permeable just like the brick formula, ChimneySaver has very low impact on the color or appearance of the concrete once applied. On denser materials such as brick, the application of the block formula will lend a sheen or gloss, if such is desired.

Unlike other concrete block formulas, ChimneySaver doesn’t use physical material to block pores and trap moisture on the inside. It’s a clear-drying, invisible top coat that turns water away from the outside and lets vapor escape from where it’s already been trapped. It also offers stain protection and is resistant to mold and fungus. 

Water or Solvent Based?

If the chimney has never been waterproofed before, a water-based sealer will be just fine. But if the chimney has had any kind of coating or sealant applied in the past, a solvent-based version will be necessary to make sure it adheres to the masonry surface so that it is effective.

Always Waterproof

No matter what chimney project we complete, be it repairs, reconstruction, or a brand-new structure, we always waterproof it when finished to ensure its integrity. Keeping water outside where it belongs is the single most effective step in preserving your chimney and making sure it lasts a long time.

We’re CMO Nashville, your local specialists for chimney repairs, waterproofing, and reconstruction. Schedule an appointment today!