The best sealer to use on brick chimneys is a silane-siloxane water repellent sealer like the Armor SX5000 or Armor SX5000 WB. They penetrate into the brick where they chemically react to form a long-lasting hydrophobic barrier within the pores that works to reduce water absorption by up to 95%. By reducing the absorption of surface water, damage and deterioration caused by surface water is also reduced. Cracking, spalling, pitting, freeze-thaw damage, and the growth of mold and mildew are reduced once sealed with a water repellent sealer.
In most cases, a brick chimney sealer is all that your chimney needs, but if your chimney has issues with deterioration, cracking, moving, or leaking, you may need more than just a chimney sealer. A chimney is made up of a few different parts, and each part should be analyzed:
- Flashing: The flashing can be found at the bottom of the chimney where the chimney and the roof leak. This is the number one source of water penetration. Make sure the flashing is in good condition, properly installed, and properly working.
- Chimney Crown: Chimney crowns are usually made of a hard material, like metal or concrete. Make sure the chimney crown is in good working condition. If the crown is made of concrete, apply a Silane-Siloxane water repellent sealer to that as well.
- Brick and Grout: At some point, a chimney will need to be repaired or repointed. If you have issues with missing grout lines, or the chimney isn’t straight, consider repairing the grout and repointing the chimney as structure will always be very important.
- Chimney Cap: The cap goes over the opening of the chimney. It helps to reduce water and snow from going down your chimney into your fire place or furnace. If you don’t have a cap, you risk your fireplace or furnace filling up with water, and you risk having your chimney deteriorate from the inside. A cap is never a bad a idea.
If you are experiencing any issues with your chimney, or are unsure if your chimney is having problems, consult a mason for a professional opinion. If your brick chimney is in great condition, and you are looking for a sealer to help reduce damage and deterioration caused by water absorption, a silane-siloxane sealer is a great choice!