Stone chimney repair specialists for Dover 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

The top of a solid stone chimney

Section R1003.9.1 of the residential code tops a masonry chimney with concrete, metal or stone, edged with a drip, and seals a bond break with caulk at every flue liner per ASTM C1283. A stone chimney is covered by that rule.

A cracked cap, a missing drip edge or a failed bond break lets water into the top courses, where it works down behind the stone. We inspect the top every time and quote cap or crown work separately from the stone.

A sample area before the full repoint

Preservation guidance recommends test panels to set an acceptable standard of work before a larger job proceeds. On a chimney, that means a small sample of repointed joints in an area you can see.

The sample lets you judge color, texture and joint profile against your stone after it dries. If you want a change, it is made before the rest of the chimney is done. Once the sample is approved, the whole repair matches it.

River rock and rounded stone chimneys

Rounded river rock has little flat surface to rest on, so the mortar does much of the holding. As joints erode, rocks lose their grip and can drop out.

Repairs on rock chimneys mean deep, careful repointing that packs mortar well around each rock and resetting loose ones in fresh mortar. Joint profiles on rock chimneys vary, from recessed to full, and we match the style of your chimney.

What cannot be seen from the surface

A surface inspection shows the stone, the joints and the details at the edges. It cannot show the condition of the barrier, lath and scratch coat behind intact veneer, or the core of a solid stone chimney.

We say so in writing. When a finding suggests a hidden problem, we explain what a small opening would involve and what it would cost, and nothing is opened without your approval.