5 Myths about Waterproofing Chimneys

Posted on August 11th, 2018

There is a lot of misinformation about waterproofing chimneys. Let's bust some of these top myths!

Myth #1: Bricks should not be waterproofed because they need to breathe

Fact - Bricks are porous and do need to breathe. That’s why it is important to use a product specifically designed for chimneys and exterior masonry. At Chimney Heroes we use a unique repellent that is vapor permeable so it will not trap water vapors in the brick. Water repellents that trap the vapors in the brick actually cause spalling rather than preventing it. This is another reason why you should never paint the exterior of your chimney. Our repellent is proven to reduce water penetration by 99.9%! If you own a Van Patten home in Clifton Park with a beautiful brick or masonry chimney, this is the perfect application to avoid future costly repairs.

Myth #2: Water cannot get into my chimney because I have a chimney cap

Fact - Chimney caps act like rain hats. If you only wore a hat the rain it would keep your head dry, but the rest of your body would be soaked. It's far better to wear rain gear head to toe if you must be in a storm. Your chimney however does not have a choice. It faces every storm, and the majority of them are unequipped for the fight! Did you know that nearly every chimney you encounter has signs of water damage. Brick chimneys absorb water like a sponge, often times leaks in attics and walls against a chimney are simply from the bricks absorbing the water from the rain, and then shedding the water below the roof line. The well defended chimney has a good screened stainless or copper chimney cap, a sealed top crown, vapor permeable waterproofing application, and proper flashing. Is your chimney equipped?

Myth #3: My chimney has held up for many years, there is no reason to do it now

Fact - We here this a lot in older and beautiful neighborhoods like Saratoga Springs, Niskayuna, and Ballston Spa. Bricks are made to be a strong building material. However, just like pressure treated wood, the weather will always win if not properly maintained. If your chimney is over 10 years old chances are it has already suffered water damage that you cannot see from the ground. Small cracks will form that you can only see up close. Water will enter these small cracks and when freezing temperatures come the cracks will enlarge. 9 out of 10 masonry chimneys already have cracks at the top of the chimney. The question is, do you want to spend a little now to prevent further damage, or budget to rebuild the whole thing once you can finally notice the damage from the ground?

Myth #4: The bricks don't matter because my chimney is lined

Fact - It is important to take care of your appliance and to have it vented safely and properly. Even if the appliance is lined or no longer venting into the masonry bricks, the bricks are the outer support structure and serve as part of the liner system. It is important to take care of the structure around liner. Water can still leak in between the liner, and can deterioration from freeze thaw period and erosion over time. The liner is a critically important part, and no chimney should be used without one. The moisture alone from the elements of combustion venting through an unlined or damaged liner would wreak havoc on the inside of the masonry chimney walls causing efflorescence and general weakening of the bricks.

Myth #5: My chimney is in good condition because it looks good on the outside

If it looks good, waterproofing will keep it this way. Maybe you think it looks good but you have noticed some white areas or moss growth. The white is called efflorescence and is a sign of water issues. Moss also grows where water sits in the chimney and the plant has found a place to root itself. Even if you do not see white or moss, water only needs a hairline crack to creep into! Once water penetrates, the damage expands with time.

Masonry repair and waterproofing should be done in the spring and summer. When temperatures drop below 40 degrees it becomes very difficult for the material to set properly. There is still time to take care of your masonry work before the damage spreads, contact Chimney Heroes today.

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