Chimney flue tile repair for Merrimac homeowners

The kinds of lining the code accepts

For ordinary residential appliances, Section R1003.11.1 of the Florida residential code lists four acceptable flue lining systems. Any repair or replacement we propose has to leave your flue inside one of them.

When a proposed fix does not clearly land in one of these categories, we say so and explain what that means for using the fireplace.

• Clay flue lining complying with ASTM C315
• Listed and labeled chimney lining systems complying with UL 1777
• Factory-built chimneys, or chimney units, carrying a listing for use inside a masonry chimney
• Other approved materials that hold up against flue gases and condensate to 1,800 degrees F without corroding, eroding, softening or cracking

When a repair changes the inside of the flue

Some repair methods add material inside the flue. A coating builds up the walls, a sleeve reduces the opening and patched joints can form small ridges. Each one changes the passage a little.

Those changes can be fine, or they can matter, depending on the appliance and the original flue size. We measure before recommending a method that changes the inside dimensions, and we write the expected result into the estimate. A small reduction may be harmless on a generous flue and a real problem on one already close to the minimum for its fireplace opening.

Finding a replacement tile that fits

A replacement tile has to seat on the one below it without leaving a ledge or a gap. Small differences in size or wall thickness can create both.

We measure the flue at the top and at the joint where the new tile will sit. If the size is unusual, we tell you before ordering and explain how the fit will be handled. Wall thickness counts as well. A thinner or thicker replacement changes how the joint seats and how the mortar sits, and a poorly seated tile is the next crack waiting to happen.

Smoke or odor in the attic

Smoke or a strong smell in the attic when the fireplace is lit means smoke is getting out of the chimney where it should not. A cracked flue or an open joint is a common cause.

Stop using the fireplace and call us. We assess the flue and the chimney where it passes through the attic and explain what we find. Smoke in the attic is not something to watch and wait on. The chimney passes framing and insulation there, and any gap that lets smoke out also lets heat reach materials that were never meant to see it.