Natural Stone Porous Materials Protection Cleaning D.I.Y.

3 methods of surface protection for your chimney

Brick is a natural choice of material for a chimney, not least because of its durability. As the Brick Industry Association (BIA) tells us, brick is made when a mixture of shale and clay are fired at around 2,000 degrees in a kiln.

“The reason the brick turns into such a durable material is that the clay/shale unit actually goes through a vitrification process in the kiln, which enables the clay particles to fuse together,” the BIA says.

Yet even with this durability, lacking the proper surface protection, a brick chimney is vulnerable to damage.

Water can wreak havoc on brick chimneys

Through a process known as water ingress, moisture can seep into the porous surface of brick, weakening it from the inside. Chimneys, of course, are particularly vulnerable to this, given that they are located out in the open with no shelter from the elements.

This is especially the case during winter, when colder temperatures tend to lead to freeze-thaw spalling. This is when moisture that has penetrated into the surface of brick freezes, therefore expanding and putting stress on the masonry.

In other words, your beautiful brick chimney is like a lamb for the slaughter. What can be done about it? In fact, there are several actions you can take.

1. Install a chimney cap

“Chimney caps, also called rain covers, are probably the most inexpensive preventive measure that a homeowner can employ to prevent water penetration and damage to the chimney,” says the Chimney Safety Institute of America (CSIA).

Not only can they prevent water from entering the chimney, they also have the added benefit of preventing animals such as birds getting in.

2. Fix structural faults

Over time, whether due to temperature changes, vibrations or movements of the foundations, cracks can appear in the masonry. Not only that, but exposure to weather can deteriorate mortar joints over time, making them more absorbent.

All of this creates ample opportunity for water to seep into the brick, and doing its damage.

3. Use a sealer to repel water

Once you’ve made repairs to your chimney, you need to waterproof it, whether it’s constructed from brick, concrete, flue tile or a combination of materials.

“Most masonry materials are porous and will absorb large amounts of water,” the CSIA says.

“Common brick is like a sponge, absorbing water and wicking moisture to the chimney interior.”

Put two coats of Dry-Treat’s DRY-TREAT 40SK™ or  STAIN-PROOF Original™ on your brick to keep water out while retaining its original look.

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