Stone chimney repair specialists for Lake Mann Estates homes

Three ways a chimney ends up stone

A stone chimney can be built of solid stone masonry, with thick units that make up the wall itself. It can be natural stone veneer, thinner stone set against a masonry or framed backing. Or it can be manufactured stone veneer, a lightweight cast product adhered over a layered backing.

From the street, all three can look alike. Their repairs do not. We identify the construction first, because the right mortar, the right method and the right questions about water all depend on it.

• Solid stone masonry
• Natural stone veneer on a backing
• Manufactured stone over lath and barrier

Filling deep joints a layer at a time

Where the old mortar came out more than about an inch deep, the brief has the deep spots filled first, packing mortar in layers of roughly a quarter inch and letting each reach thumbprint hardness before the next goes on. Most shrinkage happens as mortar hardens, so layering keeps it small.

Deep stone joints take several layers and more time. We price that time honestly, because a deep joint filled in one go shrinks, cracks away from the stone and lets water straight back in.

Recessing mortar on worn stone

When stones have worn, rounded edges, the brief recommends recessing the final mortar slightly from the face. Filling flush with worn edges makes joints look wider than they are and leaves a thin featheredge of mortar that breaks easily and lets water in.

We set the joint depth to suit your stone. On crisp cut stone, joints can come closer to the face. On weathered fieldstone, a slight recess keeps the repair durable and true to the wall's character.

Cracks that step through the joints

A crack that steps up through the mortar joints of a stone chimney often follows movement, such as a settling footing, a shifting chimney base or a failing support where the chimney meets the house.

Repointing a moving crack only closes it for a while. We trace the crack, check the base and the chimney's connection to the wall and explain what is moving before recommending a repair. When the movement is serious, the findings say so plainly.

Stone faces that flake or spall

Spalling is when the outer face of a stone flakes or pops off. Moisture moving through the stone is usually involved, especially where hard mortar or a non-breathable coating keeps it from leaving through the joints.

Lightly spalled stones can stay if the cause is fixed. Badly damaged ones are replaced. Either way, the joints around them are repointed with a compatible mortar, and any coating that is trapping moisture is discussed before anything else is done.