Standards on Chimney Caulk

Chimney Problems

• Chimneys, like other masonry materials, can develop cracks from moisture intrusion and freeze-and-thaw cycles that occur with climate fluctuations. These cracks can grow worse as the years pass and allow water to intrude into the house structures. In addition, chimneys flashings can separate from the roofing materials, allowing moisture to penetrate under the asphalt, metal or tiles. This moisture intrusion can degrade the roof itself, as well as underlying construction and cause more frequent roofing repairs and replacement. Caulk is generally used to repair these cracks and breaks. However, the term “caulk” covers a wide variety of compounds, not all of which are suitable for use with masonry or on exterior surfaces.

Chimney Masonry Repairs

• Chimney cracks may occur in the mortar between the bricks or on the bricks themselves. Generally, cracks of this kind may be caused by defects in the materials or from damage that has grown larger over time. The standard remedy for fixing these types of cracks in brick or mortar is with an acrylic latex caulk.

Chimney Flashing Repairs

• You should inspect your roof periodically to determine if flashing around chimneys is secure to avoid roof problems from water damage. Flashing is the thin metal that connects the roofing material to the brick of the chimney. Flashing actually comes in two sections, the step flashing that attaches to the roof and the counter flashing that attaches to the chimney. This flashing helps to seal out moisture from the roof and supporting materials. Generally, the standard for caulking flashing to roofing materials is the use of urethane roofing cement or silicone caulking compound. The flashing that attaches to the chimney should be caulked with a masonry type caulk, however. Chip out the old caulk and clean the area thoroughly before replacing it with new compound.

Chimney Repairs For Energy Savings

• Appearance and structural soundness are not the only reasons for caulking chimneys. Indoor heat and cooling can escape through cracks and separations in the chimney flashing. Also, exterior cold can leak into attic spaces making furnaces work harder to heat home interiors. Keeping your chimney in adequate condition helps save money in energy costs and keeps construction materials dry reducing the need for expensive repairs.