Stone chimney repair in Belmere

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.

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

Permits for bigger stone work

Building departments set their own rules on what chimney work needs a permit, and those rules differ by address. Resetting a few stones is one kind of job, and rebuilding part of a chimney is another.

When work rebuilds masonry or re-clads a chase, we look up the rule for your property before booking and explain any filing it needs. That step is written into the plan.

Chimneys that mix brick and stone

Some chimneys combine materials, a stone base with a brick upper section, or stone facing on a brick core. Brick and stone take different mortars, different joint styles and sometimes different repair methods.

We treat each part on its own terms and name both in the estimate. Brick sections are handled under brick repair, and the stone portions under this work, so it is clear what is being done to each.

Cutting stone safely around your home

Cutting and grinding stone raises fine dust. One maker's instructions caution that dust from cutting its product contains crystalline silica and call for eye protection and a properly fitted respirator when cutting.

We cut outdoors, away from open windows and doors, with wet cutting or dust collection where practical, and keep children and pets well away from the cutting area. Dust is cleaned from walkways and surfaces before we leave.