Family-owned stone chimney repair serving Corner Lake

Clearance from grade and paving

The manufactured stone instructions we follow call for a 4-inch clearance between the stone and grade, or 2 inches above a paved surface, measured from the screed in framed applications. The gap keeps ground moisture and splashing water away from the bottom of the veneer.

Landscaping changes over the years. New mulch, raised beds and pavers can close that gap without anyone noticing. We measure it at the chimney base and tell you what should be pulled back, and whether the stone at the bottom has already suffered.

Cutting and placing replacement stones

Replacement stones often need trimming with nippers, a hatchet or a saw. One maker suggests coating cut or broken edges with mortar for the best appearance, turning cut edges up when above eye level and down when below, and placing a cut edge next to a thicker stone to hide it.

Those small choices decide whether a repair disappears into the wall. Our crew cuts outdoors with dust control and sets each piece with the cut where it will not catch the eye.

Pointing joints when they are thumbprint dry

On manufactured stone, the maker's instructions call for joints to be pointed with a wood stick or metal jointing tool once they are firm, or thumbprint dry. Excess mortar is raked out and the edges around each stone compacted and sealed.

Setting times vary with the wall and the weather, so our crew checks joints by touch instead of by the clock. Even, careful jointing is what makes a repaired area read as part of the original wall.

How deep to rake out stone joints

The National Park Service's Preservation Brief 2 sets the raking depth at 2 to 2 and a half times the joint width as a minimum, so new mortar bonds and stays put. For stone masonry with wide joints, that can mean several inches.

Loose or crumbling mortar beyond that depth also comes out. The brief shows new mortar falling out of a joint that was not prepared deeply enough. We rake to a sound depth and show you the prepared joints before filling.

• At least 2 to 2 and a half times the joint width
• Deeper where mortar is loose
• Square back so new mortar locks in

Waiting before cleaning new stone joints

The brief warns that new mortar joints are especially easy to damage because they do not become fully cured for several months, and that thirty days is usually enough before cleaning a freshly repointed wall, depending on weather and exposure.

So a stone chimney that looks dusty after repointing gets a dry brushing at the end of the job and nothing more aggressive until the mortar has hardened. We give you the date when any further cleaning can safely happen.