Restoring roofs that were here before the firm was.
The historical restoration division is the smallest at Cascade — about five percent of revenue and roughly twelve projects a year — and the most editorially treated. It is the division Henrik came to Portland to work in. June Tanaka has run it since 2017. Astrid handles the tax-credit submissions and the State Historic Preservation Office coordination.
The scope is slate, cedar shake, copper, zinc, and (very occasionally) hand-split wood shingle restoration on Pacific Northwest historical structures: Queen Anne and Stick-style residences in Northwest Portland, Astoria, and Olympia; Craftsman bungalows in Eastmoreland and Irvington; small-town commercial buildings on the National Register; the occasional church, schoolhouse, or municipal building in Yamhill, Marion, and Polk counties.
About sixty percent of our restoration work is tax-credit-qualified — owners participating in the Federal Historic Preservation Tax Incentives program (twenty percent federal credit), the Oregon Special Assessment of Historic Property (twenty-five percent locally), or a combination of both. Astrid prepares the Part 2 architectural specification and the Part 3 completion certification on every qualified project. We work with the State Historic Preservation Office directly.
The other forty percent is non-qualified work — owners who want the original specification restored because that is the right thing to do for the building, regardless of credit. We treat both the same way. The methodology does not change based on the funding source.
Every project is documented end-to-end: drone aerials and elevation photographs before tear-off; substrate condition photography; original-material samples retained for the property record; daily progress photography during installation; and a bound documentation package handed to the owner at completion. The documentation package is the deliverable on every historical project, alongside the roof itself.
We do not advertise the historical division. Our work comes by referral — from architects, from preservation consultants, from the Architectural Heritage Center, from the State Historic Preservation Office, and from the owners of the roofs we have already restored. We average a six-month booking lead time on this division.
Restoration, not replacement.
Match the original material if possible. Buckingham Virginia black slate for original Buckingham slate. Western red cedar Certi-Split #1 Grade for original cedar shake. Sixteen-ounce cold-rolled copper for original sixteen-ounce copper. Twenty-ounce where the original was twenty. The substitution conversation happens only when the original material is no longer available — Monson Maine slate, for instance, has been closed since 1948, and a Monson roof is replaced with Buckingham, never with synthetic slate, and never with asphalt.
Match the original detail. Graduated coursing where the original was graduated. Snowboards where the original had snowboards. Hand-soldered copper crickets where the original had crickets. Standing-seam gable returns where the original returned in metal. Original finials retained and rebedded; original ridge cresting cleaned and reinstalled; original copper gutter profiles re-fabricated by hand from rolled flat stock if the original profile is no longer available off-the-shelf.
Document everything. The tax-credit submission requires it; the building deserves it. Every restoration we do becomes part of the property’s historical record. The next preservation team — whether that is in 2076 or 2126 — starts from our documentation.
The Failing residence, NW Portland.
The Failing residence is a 1907 Queen Anne on a quarter-acre corner lot in the Historic Alphabet District of Northwest Portland. The original roof was specified by the building’s architect, the firm of Whidden & Lewis, as Buckingham Virginia black slate, twenty-four-inch by twelve-inch standard size, graduated from a seven-inch exposure at the eave to an eleven-inch exposure at the ridge, with sixteen-ounce cold-rolled copper standing-seam gable returns, copper crickets behind the four masonry chimneys, and copper half-round gutters with original hand-soldered fish-mouth outlets.
The slate itself had performed for ninety-six years before any meaningful failure. The failure mode, when it came, was not the slate. The failure mode was the copper flashings — a twelve-ounce specification, light by the standard of the era and light by ours, that had finally surrendered after nearly a century of Pacific Northwest freeze-thaw cycling. The water entry was at the chimney saddles and the gable-return terminations. Roughly sixty percent of the slate field was salvageable; forty percent had been pulled and re-laid badly during a partial repair in the 1980s and could not be reinstalled.
Cascade was awarded the restoration in early 2025. The scope was full re-roof to the original specification: Buckingham Virginia black slate from the Buckingham, Virginia quarry; sixteen-ounce cold-rolled copper for every flashing, every gutter, every standing-seam return; hand-soldered copper crickets behind each of the four chimneys; the original Whidden & Lewis profile re-fabricated where the existing profile had been altered by the 1980s repair.
The numbers, for the public record: three hundred and sixteen thousand dollars over eighteen weeks. Four tons of slate. One thousand eight hundred and forty pounds of cold-rolled copper. A crew of six — June running it, Wyatt installing slate on the steeper north elevation, two senior installers on the south, two apprentices learning to hand-solder under June’s supervision. The original 1907 finials retained and rebedded; the original ridge cresting cleaned and reinstalled.
The project was submitted to the National Park Service in Part 2 architectural-specification form in February 2025, approved in April, installed May through September, and submitted in Part 3 completion-certification form in October. The owners received the twenty percent federal historic preservation tax credit and the twenty-five percent Oregon Special Assessment in the 2025 tax year.
The Failing roof will be standing in 2126.
The Failing roof will be standing in 2126. The work we did in 2025 will be the work the next preservation team starts from.
— June Tanaka, Historical Restoration foremanQuestions preservation consultants and owners have asked us.
Do you handle the historical preservation tax credit paperwork?
Yes. Astrid prepares the Federal Historic Preservation Tax Incentives submission (Part 2 architectural specification and Part 3 completion certification) and the Oregon Special Assessment paperwork. We work with the State Historic Preservation Office directly. We have submitted forty-one projects in the last decade; thirty-nine have been approved on the first submission.
What slate quarries do you specify for Pacific Northwest historical work?
Primarily Buckingham Virginia black slate — the dense, low-water-absorption slate that was the standard for Pacific Northwest historical work from 1890 through 1940 and remains the standard for restoration today. Occasionally Vermont Glendyne semi-weathering gray-green for projects where the original spec called for a gray-green slate. Never synthetic slate on a tax-credit project; the National Park Service does not accept synthetic substitution.
How long does a historical restoration project take?
Typically twelve to twenty-two weeks from site visit to completion of installation. The tax-credit submission and approval cycle can add another four to eight weeks of front-end paperwork before installation begins. A full Queen Anne slate restoration with copper detail runs the longer end of this range; a partial slate-and-flashing repair runs the shorter.
What does a full historical slate restoration cost?
On a typical Pacific Northwest Queen Anne (twenty-eight hundred to thirty-four hundred square feet, slate with copper detail), the budget range is two hundred and eighty thousand to four hundred and twenty thousand dollars. The federal tax credit recovers twenty percent of qualified rehabilitation expenses; the Oregon Special Assessment recovers twenty-five percent. For qualified owners the net cost is materially lower than the gross.
Request a preservation consultation.
June and Astrid will both attend the initial site visit on any historical project. The conversation typically runs ninety minutes. We will tell you what we can and cannot do for the building.