Draper · Salt Lake County
Tall Stacks and Hillside Masonry in Draper
A chimney on a Draper hillside is often the tallest, most exposed, least sheltered thing on the property, and it is engineered to a standard most owners have never thought about.
Height above the roof is a structural question
A flue has to clear the roof by a certain margin to draft properly, and on a steeply pitched hillside house that margin can put several feet of masonry or several feet of chase up in open air with nothing bracing it. That section takes full wind load from every direction, plus whatever ground movement the house transmits. Over years, an unbraced tall stack works its mortar joints loose from the top down. It is not sudden and it is not dramatic. It shows up as joints you can rake out with a fingernail and, in the worst cases, a visible tilt at the top few courses.
Bracing and rebuilding the upper section is real work rather than a patch, and it is worth knowing that a stack in that condition is a life-safety matter as much as a leak. Masonry coming off a roof at that height goes a long way.
Stucco chases crack for a different reason
The hillside subdivisions mostly have framed chases finished in stucco rather than brick. Stucco is rigid and the timber behind it moves with temperature and moisture, so hairline cracking at corners and around the chase cover is normal and expected. What is not acceptable is a crack that has been left long enough to admit water, because the framing behind stucco has no way to dry once it is wet. We look for staining, soft patches and rust tracks below the chase top, and we deal with the cover and the flashing before anyone touches the stucco. Repairing the finish while the water source is still active is a way to hide the problem for a season.
The old part of town
Down in the original grid the masonry is genuinely old, and it wants a lighter hand. Old brick is soft and the mortar it was laid with was softer still, deliberately. Any repointing here uses a mix matched to what is already in the wall, not a modern high-strength mortar, because the harder material always wins and it wins against the brick face.
Crowns and the order of work
Whatever the era, the crown is where we start. It is the concrete slab at the top that sheds water clear of the flue and the brick, it is thin, it takes the full weather, and it cracks first. Repairs done below a failed crown get undone from above. Crown, then flashing, then joints, then any surface treatment, in that order.
Questions
Chimney Repair in Draper — common questions
The top of our chimney looks like it is leaning. What should we do?
Stop using the fireplace and have it looked at promptly. A lean at the top usually means mortar has failed on one side, and a tall exposed stack that has started to move is a falling hazard as well as a chimney problem. It is assessable from the ground in most cases.
Our stucco chimney chase has hairline cracks. Is that serious?
Hairline cracking at corners is normal movement in stucco over framing. It becomes serious when it opens enough to let water reach the framing behind, which cannot dry. We check for staining and rust tracks below the chase top to tell the difference.
How long should a chimney crown last?
A properly formed crown with an overhang, a drip edge and an expansion joint around the flue can last decades. A thin skim of mortar troweled flat across the top, which is what many were given, tends to start cracking within several years in this climate.
Can you rebuild only the top of the chimney?
Frequently that is exactly the right repair. Damage concentrates in the exposed section above the roofline, and taking down and rebuilding those courses restores the structure without disturbing sound masonry below. We photograph the joints to show where the sound work starts.
Also in Draper
Our other services here
Chimney Sweep Inspection Fireplace Repair Installation Gas Fireplace Caps & Dampers Dryer Vents All Draper services
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