Stucco Chimney Repair for Twin Cities Houses

Stucco-clad houses are a familiar sight in the older Minneapolis and St. Paul neighborhoods. Historic district survey forms, such as the ones for Prospect Park, record stucco houses next to bungalows and Craftsman homes. Many have a chimney finished in the same stucco, and some had it added later as a quick cover for tired brick. Either way, the stucco is a skin. Once water gets behind it, it has nowhere to go.

Water usually enters at the top, through a cracked crown or a crack in the stucco itself, and soaks the masonry behind. In a winter with about 75 freeze-thaw days at MSP, by our count from NOAA normals, that trapped water freezes and pushes the stucco off the wall from the inside. We check where it is coming from, tap and probe for loose areas, and write a price. Stucco chimney repair typically runs $900 to $4,000, and a new crown with a drip edge $1,000 to $3,000.

Signs you need this

• Cracks in the stucco that widen each spring
• Bulges or hollow-sounding patches when tapped
• Brown or rust-colored stains running down the chimney
• Pieces of stucco on the roof or in the yard
• Peeling paint or damp plaster inside on the chimney wall

How we do it

1. Free inspection and moisture checkWe look at the crown and cap, tap the stucco for hollow spots and check inside for damp.
2. Find the waterRepairs only last if the crown, cap and flashing are stopping water at the top.
3. Remove loose stuccoFailed areas come off down to sound material so we can see the masonry behind.
4. Repair the masonry and re-stuccoDamaged brick or block is fixed, then new stucco is applied in coats and matched to the old finish as closely as possible.
5. Close up the topIf the crown is part of the problem, a new crown with a drip edge goes on.

Why stucco chimneys fail from the top

The current Minnesota Residential Code, through IRC R1003.9.1, calls for a masonry chimney to have a concrete, metal or stone cap that is sloped to shed water and has a drip edge. Many older stucco chimneys have a flat mortar wash with no drip edge, so water runs straight down the face and finds the first crack. Fixing the top is often half of a stucco repair.

Patch, re-skin or rebuild

Small cracks with sound stucco around them can be patched. Large hollow areas need the stucco removed and redone. If the brick behind has failed badly, the honest answer may be a partial rebuild before new stucco goes on. We price the options side by side.

• Patch: hairline cracks, sound stucco, no damp inside
• Re-skin: wide cracks, hollow areas, staining
• Rebuild the top first: soft or loose brick behind the stucco

Historic and stucco together

If a stucco house sits in a Minneapolis or St. Paul historic district, the city may review exterior repairs. St. Paul requires a permit for exterior repairs in a Historic Preservation Area regardless of value. We check before quoting and help you put together photos and a scope.