Repairing Springville Chimneys That Sit Against the Mountains

The mechanism, properly explained

Brick and mortar are full of tiny pores. Those pores fill with water, and water expands as it turns to ice. One cycle does nothing measurable. Several hundred cycles over several winters break the bond at the surface, and the face of the brick begins to shed in thin plates. Masons call it spalling and it always starts at whichever part of the chimney stays wet longest.

What makes the base of the mountains different is not that it gets colder, it is that it swings. Nights near the range clear out and drop hard; days can be well above freezing on a sunny face. That is a lot of crossings in a season. The north and west faces of a stack, which never dry properly between them, take the worst of it.

Where water gets in

Almost always the crown. A chimney crown should be a cast concrete slab that overhangs the brick on all sides with a drip edge, sloped so water leaves the structure. A great many chimneys were finished instead with a thin smear of mortar troweled flush to the brick edge. That cracks within a few years, and once it cracks it functions as a funnel directly into the top of the wall.

Repointing that will not make things worse

When we cut out failed joints we match the new mortar to the strength of the surrounding brick rather than to the strongest mix available. This is the part homeowners are rarely told about. Old soft brick paired with a hard modern mortar means the joint no longer yields, so every bit of seasonal movement is taken by the brick face instead, and the brick spalls. Matching down is not cutting corners, it is the correct specification.

Steep roofs and the season

A lot of houses on the higher streets have steep pitches designed to shed snow, and that is a real constraint on when work can happen safely. Add to it that mortar and crown concrete need above-freezing temperatures to cure and you get a working season that runs spring through fall. If a chimney is unsafe in the middle of winter we will make it safe and cover it, then come back and do the permanent repair properly.

When it is a rebuild

Above the roofline, a stack with widespread joint failure, displaced brick or a lean is a rebuild rather than a repair. We will show you why on photographs and price it honestly. Patching a stack that has lost its integrity buys a season and wastes the money.