Chimney Masonry Repair · Shoreline, WA

Repointing crumbling mortar on a mid-century Shoreline chimney

Mortar you can rake out of a joint with a house key, and brick faces flaking off onto the ground below, are the two conditions that bring most Shoreline homeowners to this page. Both are ordinary on a chimney of this city's age, and both are fixable — but the fix depends far more on what the existing masonry is than on what a product catalog recommends.

Shoreline's median year of construction is 1969, older than Seattle's 1976 and well older than King County's 1983. That single number sets up the whole mortar question below.

Reviewed by Chimney4u editorial team · Last updated 2026-08-27

Matching mortar on a chimney of Shoreline's vintage

Repointing is the removal of deteriorated mortar from the joints and its replacement with new mortar. The whole job turns on one decision that is easy to get backwards: what the new mortar should be.

The selection rule. The industry rule is to choose the mortar type with the lowest compressive strength that meets the requirement. Stronger is not a safety margin; it is a different material behaving differently in the same wall.
The repointing rule. Repointing mortar has to be equal to or lower in compressive strength than the original, because stronger mortar concentrates stress at the brick-and-mortar interface and spalls the face off the brick.
Why that bites here. A chimney from Shoreline’s main construction decades sits between the two familiar cases. It is not soft historic lime work and it is not modern masonry built to a documented specification, so the answer is neither the softest type on the ladder nor the strongest — it is whatever the existing joint actually is.

Why brick faces come off in this climate

Spalling is the brick face flaking, popping or crumbling away. Brick and mortar pull water in through microscopic capillaries and dry themselves by evaporation, and Shoreline gets 38.6 inches of rain in an average year, about five of them in January. A face that goes into a cold snap saturated has water inside it when that water expands.

Replacement brick is specified for the exposure, not for the color match alone. Brick used where it will be wet and freezing has to meet the severe weathering grade — which above an exposed Shoreline roof is the operative condition, not a theoretical one.

The joint profile, and the window to do it in

Two things decide whether a repointed joint sheds water for decades or holds it: the profile it is finished to, and the conditions it cures in.

Profile. Concave, V and grapevine profiles resist water penetration best on exterior brickwork. A joint struck flush or raked back on an exposed chimney gives water somewhere to sit.
Tooling. The joint is tooled at thumbprint hardness — firm enough to hold the shape, soft enough to compress. That is a timing judgment during the work, not a pass at the end of the day.
Depth and lifts. Cut back to a uniform depth of at least twice the joint width, then packed in thin lifts so the mortar consolidates instead of shrinking away from the brick.
Head joints by hand. The short vertical joints are chiselled, not ground — a grinder takes brick with it and leaves a wider joint than the one it replaced.

The Shoreline exemption that does not apply on the water side

Repointing is the classic job people assume needs no paperwork. In Shoreline that assumption is worth checking, because of where the exemptions stop.

That carve-out is not abstract here. Shoreline fronts 3.4 miles of Puget Sound, and the neighborhoods on that side — Richmond Beach, Innis Arden and The Highlands among them — step down toward the water on steep ground.

Scope matters as well. Repointing joints is one thing; taking a chimney apart above the roof line and rebuilding it is another, and the second is a conversation with the city whatever the lot. Where the damage has moved out of the mortar and into the brick, repointing stops being the honest answer.

Local considerations in Shoreline

Shoreline's median year of construction is 1969, against 1976 in Seattle and 1983 across King County, so the typical chimney here is neither historic soft-lime masonry nor modern work built to a documented specification.
Repointing mortar must be equal to or lower in compressive strength than the original, because stronger mortar concentrates stress at the brick-and-mortar interface and spalls the brick face.
Shoreline averages 38.6 inches of rain a year with about five inches in January, so masonry here goes into cold weather wet and the repointing window is genuinely seasonal.
Brick used where it will be wet and freezing must meet the severe weathering grade, which matters for replacement units on an exposed chimney top rather than only for new construction.
Shoreline permit exemptions do not apply to properties containing a critical area such as a steep slope or beach, which describes a share of the lots on the city's 3.4 miles of Puget Sound side.

What the job includes

A close look at the joints where access allows, including a light scrape to find the depth at which sound mortar begins
A written scope and price before anything is opened up, naming the areas, the cut-back depth, and the mortar type matched to the existing joint
Identification of what is wetting the masonry, because new joints packed under an open water path have a short life in this climate
Deteriorated mortar cut back to a uniform depth of at least twice the joint width, or deeper where sound mortar starts further in
Head joints chiselled by hand instead of ground, and mortar slivers cleaned off the brick so the new work bonds
Repacking in thin lifts, tooled at thumbprint hardness, finished to a profile that sheds water on an exposed chimney
Individual broken or heavily spalled bricks cut out and replaced in a unit rated for wet, freezing exposure, shown to you before it goes in
Photographs of the same joints before and after, from the same angles where practical

What it does not include

The crown — the sloped slab on top of the chimney. It is a separate scope, and on a mid-century Shoreline chimney it is frequently what put the joints in this condition in the first place
Flashing. The metal sealing the chimney to the roof is its own detail and its own quote
Anything inside the flue. Repointing addresses the outside of the chimney only, so relining and liner repair are booked separately
Sweeping and creosote removal. Masonry work does not clean the flue
Water repellent. A breathable repellent belongs on sound masonry as a last step, never as a substitute for repointing
Rebuilding a section, or any work calling for engineered design or seismic reinforcement
The structural assessment where the signs point to movement rather than weathering. That belongs to a structural engineer, and the masonry work follows it
Filing the permit application. New Shoreline applications go through the city’s eTRAKiT portal, and what is required is the city’s determination

What to look for

Mortar you can rake out of a joint with a house key: The binder is gone. That joint is no longer keeping water out of the wall, whatever it looks like from the ground.
Joints receded more than about a quarter inch behind the brick face: Erosion past the point where the joint sheds water. It now collects it instead.
Thin flakes of brick face in the gutter or on the ground below: Spalling. The face is coming off, which means water is getting into the unit and freezing there.
A chimney that was sealed or painted and got worse: A film-forming coating trapping moisture behind it. The coating has to come off before the masonry can be repaired properly.
White powdery bloom that returns after you clean it off: Salts being carried out of the masonry by water moving through it. It is a moisture indicator, not a cleaning problem.
The masonry above the roof line looks far worse than the rest: Ordinary in a city this exposed — that section takes driven rain from every side and has no building behind it — but it is also where repointing most often turns into a rebuild conversation.
Stepped or diagonal cracking, cracks running through bricks, or a chimney out of plumb: Movement rather than weathering. That is assessed before any joint is touched.

What changes the price

We do not publish a headline figure, because it would be a guess about your chimney. These are the things that genuinely move the number, and we put a real one in writing after we have looked.

How much of the chimney needs work: Spot repointing, a full face of joints, and every face of the stack are three different jobs. The visible bad patch is rarely the boundary.
Access and height above the roof: Pitch, chimney height, and how close a vehicle can get to the lot. Shoreline's slope neighborhoods take longer to stage than its flatter east side.
Joint condition and how the mortar comes out: Mortar that rakes out easily is faster than mortar that has to be cut back hard, and head joints chiselled by hand are slower than a grinder pass would be — deliberately.
Mortar matching and brick replacement: Matching the existing joint, and sourcing a replacement brick rated for wet, freezing exposure that also resembles a sixty-year-old unit, both add time before any work starts.
Whether a water source has to be corrected first: A failed crown or flashing above the joints has to be dealt with before repointing, or the new joints inherit the same problem.
The weather window: Mortar needs a dry stretch and a wall temperature in range. Shoreline's wet season narrows when the work can actually be done.
Whether the city is involved: A critical-area lot, or a scope that goes past the joints into a rebuild, adds application and inspection time to the schedule.

Chimney Masonry Repair in Shoreline — common questions

Our Shoreline house is from the 1950s. What mortar should the repointing use?: Whatever matches the existing joint, which is established by examining it rather than by the build year. The industry rule is to choose the mortar type with the lowest compressive strength that meets the requirement, and for repointing specifically the new mortar must be equal to or lower in strength than the original — stronger mortar concentrates stress at the brick-and-mortar interface and spalls the brick face off. A chimney from Shoreline's postwar decades is neither soft historic lime work nor modern masonry, so the mix should be named in the written scope before anything is cut out.
The brick is flaking. Can I seal or paint the chimney instead of repairing it?: No, and it makes things worse. Sealing a spalling chimney with waterproofing or a non-permeable paint traps moisture behind the coating and accelerates the decay, and the masonry industry recommends against film-forming coatings on brickwork in freeze-thaw environments altogether. A breathable, vapor-permeable repellent is a reasonable last step on masonry that is already sound. It is not a repair, and on a chimney taking 38.6 inches of rain a year it does not become one.
We are on a bluff lot in Richmond Beach. Does that change the permit question for repointing?: It can, and this is the part most homeowners miss. Some Shoreline projects qualify for a permit exemption, but exemptions do not apply to properties containing critical or environmentally sensitive areas such as steep slopes, beaches, streams, wetlands and lakes — a description that fits many lots on the city's Puget Sound side. The city also advises that work not on its permit exemptions handout will likely need a permit, and new applications are accepted only through its eTRAKiT portal. Requirements change and depend on the property, so confirm with Shoreline Planning & Community Development before work starts.
When is the right time of year to repoint a chimney in Shoreline?: A dry stretch with wall temperatures in range. Repointing wants wall temperatures between 40 and 95 degrees Fahrenheit, and Shoreline averages 38.6 inches of rain a year with roughly five of them in January, so much of the wet season is out. Getting the chimney looked at and scoped is not weather-dependent — that can happen in the rain, and often reads better in it — but the packing, tooling and curing need the window.
Why is the part of the chimney above the roof always the worst?: It is the only part with weather on every side, no building behind it, and nothing above it. Heavy wind-driven rain will penetrate a single wythe of brickwork regardless of materials or workmanship, and above the roof line there is no second wythe and no interior to dry into. On an exposed Shoreline chimney that section is also where repointing most often stops being sufficient — when the damage has moved into the brick rather than the joints, or the proportion of failed joints keeps rising, the honest answer is a rebuild of that section rather than more mortar.

Sources

Table B25035, Median Year Structure Built — Shoreline city, Seattle city, and King County, Washington (ACS 2020–2024 5-year estimates) — U.S. Census Bureau American Community Survey, via Census Reporter. Accessed 2026-08-27.
Technical Notes on Brick Construction 46 - Maintenance of Brick Masonry — Brick Industry Association, December 2017. Accessed 2026-08-27.
Technical Notes on Brick Construction 8B - Mortars for Brickwork: Selection and Quality Assurance — Brick Industry Association, March 2020. Accessed 2026-08-27.
Technical Notes on Brick Construction 9B - Manufacturing, Classification and Selection of Brick: Selection, Part 3 — Brick Industry Association. Accessed 2026-08-27.
Common Problems with Brick Masonry — U.S. National Park Service (originally published 2008; page states last updated June 29, 2018). Accessed 2026-08-27.
Get a Permit — City of Shoreline, Planning & Community Development. Accessed 2026-08-27.
Technical Notes 6A - Colorless Coatings for Brick Masonry — Brick Industry Association. Accessed 2026-08-27.
Preservation Briefs 2: Repointing Mortar Joints in Historic Masonry Buildings — U.S. National Park Service, Heritage Preservation Services (Robert C. Mack, FAIA and John P. Speweik), October 1998, ISSN 0885-7016. Accessed 2026-08-27.
Quick Facts — City of Shoreline. Accessed 2026-08-27.
Frequently Asked Questions About Permits — City of Shoreline, Planning & Community Development. Accessed 2026-08-27.
Permit Services — City of Shoreline. Accessed 2026-08-27.
Technical Note 7 - Water Penetration Resistance: Design and Detailing, November 2017 — Brick Industry Association. Accessed 2026-08-27.

Next step

Start with an inspection

Tell us what you have noticed. We will look at the chimney, show you what we found, and put a price on the work before anything begins.

Request an inspection Call (206) 573-4487