St. Paul Tudor — Natural Slate Restoration

Summit Avenue runs 4.5 miles from the Cathedral of Saint Paul west to the Mississippi River bluffs — one of the longest stretches of Victorian residential architecture in the country. The tudor on this side street was built in 1927 in the Merriam Park neighborhood adjacent to the Summit corridor, and it had worn the same Vermont slate roof since original construction. That's nearly 100 years of service from the original material.

By 2024, the slate was not failing — it never really fails if you catch the flashing before it does. The copper step flashing at the two dormers and the chimney saddle had corroded through, and the lead-coated copper valley liners were pinholing. The slate itself was 80 to 90 percent sound. The job was a selective restoration: remove and stack the existing slates by course, strip the failed flashing and valleys, replace with new 20-ounce copper throughout, reinstall original slates, and replace the estimated 15 to 20 percent that had spalled, cracked, or softened.

Vermont slate at 12/12 pitch is demanding work. The crew lead who ran this job has 14 years of slate experience — you cannot hand this kind of work to a general roofing crew. Slates are sorted by thickness before reinstallation, set on copper slater's hooks rather than nailed through, and each course is checked with a raking light before the next goes over it. Any slate with a ring that doesn't ring true when tapped comes out.

The replacement slates came from a Vermont quarry and were matched to the existing grey-purple tint. The chimney saddle was rebuilt in copper. Final result: a roof that will carry this house through another generation before anyone needs to think about it again.