Your fireplace hearth, repaired and measured in McDonald

Wood left under a hearth from the original build

Hearths were often poured over wooden forms, and the code is plain about what should happen afterward. Section R1001.9 says combustible material shall not remain against the underside of hearths and hearth extensions after construction.

Sometimes a repair reveals boards or plywood still in place under the slab. That finding changes the job from a surface fix to a support fix. We show you what was found, explain the options for removing it or rebuilding the extension on proper support, and wait for your approval before going further.

White deposits on a brick hearth

White, powdery deposits on brick or grout are salts carried to the surface by moisture. On a hearth they point to water somewhere, whether a spill that soaked in, a leak above the fireplace or damp rising from below.

We note where the deposits sit and follow the moisture back to its source. Cleaning them off is easy, and keeping them away depends on stopping the water. If the source is a roof or chimney leak, that repair is scheduled separately and the hearth is finished after it.

• A spill that soaked in
• Water from a chimney or roof leak
• Damp rising from below

Broken corner pieces on a hearth

Corners and the ends of edge pieces take hard knocks, and they are often the first parts of a hearth to break. A broken corner can expose the setting bed and let ash and moisture into the joint.

We cut out the broken piece cleanly and replace it with a matching corner or edge unit. Where the old profile is no longer made, we suggest a replacement shape for both corners so the hearth stays symmetrical.

The front edge of a raised hearth top

The front edge of a raised hearth top, often a bullnose or a separate edge piece, carries weight when people sit and takes kicks from shoes. Its bond tends to break before the rest of the top.

A loose edge piece is removed, cleaned and reset on a fresh bed. If it keeps coming loose, we check the support under the overhang, since an edge that hangs past its base has little to hold it.