Chimney services, Portland metro
Tuckpointing and brick repair for Portland chimneys, matched mortar, no smear jobs
We grind failed mortar joints on Portland-area chimneys out to depth and repoint them with mortar matched to the age and softness of the brick, and we replace spalled brick on the stack above the roof. Every face is photographed before and after.
Updated
What you are seeing
These are the signs that the mortar on a Portland chimney has started to let go, most of them visible from the sidewalk with a pair of binoculars.
- Sand and grit on the roof or in the gutter below the chimney after a hard rain.
- Mortar joints recessed well behind the brick face, or missing in spots you can see daylight through.
- Brick faces popped off, leaving a rough orange core, mostly on the top courses and the weather side.
- White, chalky deposits spreading across the brick, heaviest just below the crown.
- Moss or a green film thickest on the shaded north side of the stack.
What we do on a tuckpointing visit
Tuckpointing is grinding, mixing and packing done in a strict order, because a joint smeared over a dirty, shallow cut falls out again within a few winters.
Walk every face and photograph the joints
We look at all four faces from the roof and photograph each one with a scale in the frame. Then we rake a few joints with a pick to learn how deep the soft mortar goes, tap the brick for hollow faces about to spall, and check the crown and flashing while we are there.
Grind or rake the failed joints to depth
Failed mortar is removed down to sound material, deep enough to hold the new mortar, with a grinder fitted with a vacuum shroud or by hand on soft old brick that a blade would chew. A shallow smear over a dirty joint is a common failure in this trade, so the cut is square-backed and blown clean before anything goes in.
Match the mortar to the brick
Old Portland brick laid in lime mortar is softer than a modern cement mix, and a mortar harder than the brick forces every freeze and every bit of movement into the brick face, which then spalls. We mix for the brick in front of us, lime-rich for a 1910s stack and a standard mix for a 1970s one, and match the color and sand first.
Cut out and replace spalled brick
A brick that has lost its face keeps drinking water through the exposed core, so it comes out. We drill and chisel the unit free without disturbing its neighbors, clean the pocket, and set a matching brick in fresh mortar, using a reclaimed brick when the original color and size are no longer made.
Pack and tool the joints, then keep the rain off
New mortar goes in with a pointing trowel in lifts, pressed hard against the back of the cut so there is no void, then tooled to match the profile of the surviving joints. Fresh lime mortar needs days to cure and dislikes both rain and frost, so the stack gets covered and the job is timed to a dry window.
Clean up and send the photos
Mortar smears are brushed off the brick face before they set, the roof and gutter are cleared of grit, and the drop cloths come up. You get the before and after photos of each face, a note on what the crown and flashing looked like, and a date to check the joints again.
Why the mortar has to be softer than the brick
Mortar is meant to be the sacrificial part of a brick wall: softer than the brick, so that moisture and movement work on the joint, which is cheap to renew, and not on the brick, which is not.
Chimneys from the early 1900s were often laid with lime mortar and brick fired softer than today's. Repoint them with a hard modern cement mortar and the next freeze pops the brick faces instead of the joints.
So the mix is chosen after the brick is, with more lime and less cement for old soft brick, and tested against a hidden joint for color once it has dried.
Efflorescence, moss and the north face
White bloom on the brick is efflorescence, the minerals left behind when water that got into the masonry evaporates back out, and it is the early warning that the joints are passing water.
Moss does the next part. It takes hold on the shaded north and east faces, holds water against the joints through the wet months, and keeps them damp long after the weather side has dried. With measurable rain falling on some 157 days a year and about 32 freezing nights in the same season, the wet joint freezes, loosens and sheds sand.
That is why the damage on a Portland chimney is lopsided: the north face and the top courses often go first. We scrape the moss off before grinding, and a breathable water repellent after the joints cure slows the cycle down.
Repointing an unreinforced brick chimney does not brace it
Tuckpointing keeps water out of a chimney; it does not make an unreinforced brick stack safe in an earthquake, and we say so up front.
The State of Oregon puts the odds of a magnitude 7.1 or larger Cascadia earthquake in the next 50 years at about 37 percent, and tall, slender masonry chimneys are the most vulnerable, liable to break and fall onto the roof. Portland's URM program covers buildings, not house chimneys, but the material fails the same way.
Full, fresh joints may help a chimney hold together as one piece in small shaking. For the big one, the choices include bracing, which reduces the hazard without removing it, a metal chimney in place of the upper brick, or taking the stack down to the roof and venting another way.
When the stack is past repointing and a rebuild takes over
Repointing stops making sense when the joints have washed out behind the face brick, the brick is spalled across most of a face, or the stack leans or has pulled away from the house.
At that point every joint is new mortar between broken brick, and the money is better spent taking the chimney down to sound brick, usually at or just above the roofline, and relaying it with new flue tile and a proper crown. We say which side of that line your chimney is on from the photos.
What moves the price of tuckpointing
The board price assumes a chimney above the roof with a handful of failed joints, so the following push it up.
- How much of the chimney needs work: a few joints on one face, or every joint on all four.
- How high the roof is and how steep, since scaffold or roof hooks change the setup for the whole job.
- Spalled brick to cut out and match, especially on a street face where the color shows.
- A lime mortar match for 1900s to 1920s brick, which is mixed and color-tested rather than poured from a bag.
When a repair stops making sense
The chimney moves from repair to rebuild when the brick itself is failing rather than the joints between it: faces spalled across most of a side, cores exposed and soft, or brick that moves under a hand.
A lean or a gap opening between the stack and the siding is a structural problem, not a pointing problem. That chimney gets a Level 2 inspection and the rebuild conversation, and the fireplace stays out of use until the inspection says otherwise.
Tuckpointing: common questions
How deep do you grind the joints when tuckpointing a chimney?
Until we reach sound mortar, with a square-backed cut deep enough to hold the new mortar, which on a badly weathered stack goes well past the surface. A shallow skim over the old face is the repair that fails, because the new mortar has nothing to grip and pops out within a few winters. The cut is squared and cleaned before packing.
Can tuckpointing match the mortar color on a 1920s brick chimney?
Close enough that the repaired joints blend once the mortar has cured and weathered a season. We match the sand, the lime content and the tooling profile to a cleaned original joint, and test a sample on a hidden face. Fresh mortar often reads lighter for a few months, so judge it in spring.
Why does hard mortar damage old chimney brick?
Because the mortar is supposed to be the weaker partner. Old brick is soft and porous, and when the joints around it are harder than the brick, water, frost and the slow movement of the chimney work on the brick face instead of the joint, and the face spalls off. Lime-rich mortar flexes and lets moisture out through the joint.
Does tuckpointing stop efflorescence on a chimney?
It stops the water that causes it when open joints are the way in. That is usually the case when the white bloom sits along the joints rather than under the crown. The deposits already on the brick weather off or brush off dry. If staining returns after repointing, the crown, cap or flashing is the remaining path.
Can a chimney be repointed during the Portland rainy season?
Yes, in dry windows, with the stack covered while the mortar cures. Lime mortar needs several days without rain running over it and without frost, so between November and March we watch the forecast and keep the stack under a tarp between visits. Spring through early fall is simpler and is when we prefer to book it.
Does tuckpointing make a brick chimney safer in an earthquake?
Not in any way you should count on. Full joints may help the brick act as one piece in small shaking, but an unreinforced chimney can still break at the roofline in a large quake, and bracing reduces that risk without removing it. Repointing is water work; the earthquake question is a separate conversation we are glad to have.
Related pages
Where we do this
We repoint and repair brick chimneys in every community on this list, Woodlawn and Alberta included, out to Oregon City and Forest Grove.
Ready to book a sweep?
Call with what the fireplace is doing, or text a photo of the opening and one of the chimney top, and we will name the service and its posted price before we come out.