Masonry Chimney Repair in Provo

Freeze-thaw is the whole story

Brick and mortar hold water the way a sponge does. Utah Valley crosses the freezing point and comes back over it dozens of times between October and April, and each crossing expands the water trapped in the pore structure a little further. Eventually the face of the brick lets go. The technical word is spalling; from the ground it looks like a chimney shedding orange flakes and dust onto the roof.

Shaded faces fail first because they get the least sun to dry between cycles. If one side of your stack looks far worse than the others, that is not your imagination and it is not bad luck.

A failed crown does more damage than a failed brick

The crown is the sloped slab across the top of the stack. Its job is to throw water clear of the masonry and overhang the brick by an inch or so. A great many older chimneys in this city were finished instead with a thin skim of mortar troweled flat, and mortar in that thickness always cracks. Once it does, rain runs down the inside of the brickwork rather than off the edge, and the damage happens in places you cannot see: the tile joints, the smoke chamber, the framing where the chimney passes the roofline, and finally a brown ring on a bedroom ceiling.

Why the wrong mortar makes an old chimney worse

This matters on the pre-war brick in the older parts of town. Those stacks were laid in soft, lime-rich mortar, and the design assumption was that the mortar would be the part that wears out. You repoint it every few decades and the brick survives. Repoint that same chimney with a hard modern Portland mix and you reverse the relationship: the joints become stronger than the brick, so the next freeze cycle takes the face off the brick instead of the mortar. We match the mix to the masonry in front of us, and on a hundred-year-old stack that means something softer than a new build would get.

Repair, rebuild, and the honest difference

Tuckpointing, a cast crown, new flashing and a handful of replacement bricks will save most chimneys we look at. Some are past that point. If the stack is out of plumb, if the tile liner has dropped or shifted, or if you can push a screwdriver into the joints across most of its height, repointing is money spent on work that will need doing again within a few years. We will tell you which of those you have, and show you the photographs the call was based on.