Expert stone chimney repair in Audubon Park

Cleaning manufactured stone the gentle way

Dirt on cast stone needs a light touch. The instructions we follow say it can be removed with granulated soap or detergent in water and a bristle brush, rinsed right away with fresh water. They rule out wire brushes, acid or acid-containing products, power washing and sandblasting.

Those methods can strip the colored surface of cast stone and leave marks that do not come out. We clean with the gentle method first and never reach for pressure or acid on manufactured stone.

• Detergent, water and a bristle brush
• Rinse right away with fresh water
• No wire brush, acid, pressure or blasting

Sealers on stone, used with care

One manufactured stone maker states that sealers are not necessary on its products. If one is used, it should be a breathable silane, siloxane or silane-siloxane blend, and the maker warns that sealers may darken the stone and slow the natural movement of moisture out of it, raising the chance of efflorescence or spalling.

For natural stone, the sealer's own data sheet decides whether it suits the stone. We recommend a sealer only when there is a clear reason, and we name the product in writing.

Curing fresh joints on a stone chimney

High-lime mortars harden as they lose water and take up carbon from the air, and drying too fast can leave them chalky and weak. Preservation Brief 2 describes misting repointed areas with a fine spray for a day or two and covering walls with burlap for the first three days, with any plastic tented away from the wall.

What we do depends on the mortar and the day. We protect new joints from hard rain and strong sun and leave you short notes on what to avoid while they cure.

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.

Water stains inside near a stone chimney

Stains on a ceiling or wall beside a stone chimney can come from the flashing, the cap, open joints or water behind veneer. The stain inside does not always sit directly below the entry point.

We check the outside of the chimney from the roof and the base, and the attic where it is accessible, to find the path. Leak repairs that are not stone work, such as flashing or cap work, are quoted on their own lines.