Period-correct, on the register.

An 1890 farmhouse on the Jonesborough Historic Zone.

The owners had inherited the home in 2019 and had been patching the original cedar-shake roof every year since. By spring 2025, two valley failures had stained the dining-room ceiling and a structural engineer had flagged decking sag over the kitchen. The roof had to come off. The problem: the home sits inside the Jonesborough Historic Zoning Commission jurisdiction, which requires period-correct exterior materials approved before any work begins.

Slate-look Class 4, not real slate.

Authentic slate would have run $148,000 on this roof and required structural reinforcement to handle the additional load. We modeled three alternatives:

1. Real slate — period-correct, $148K, +12K structural, 75+ year life.
2. Synthetic slate composite (DaVinci) — visually convincing, $72K, no structural work, 50 year warranty.
3. Atlas StormMaster Slate — Class 4 asphalt in a slate-pattern shaped tab, $34K, no structural work, 50-year material + 10-year Palisade workmanship.

We submitted all three options to the HZC with photographs of installed examples in the region. The board approved Option 3 (StormMaster Slate) on first submission — citing the visual match from 30 feet and the Class 4 hail rating as future protection. Approval took 5 weeks from submission.

Four days, six surprises.

Tear-off revealed three layers (asphalt 1985, asphalt 1972, original wood shake) — typical for a home this age. We’d quoted two layers. The third was tear-off labor only ($1,400 add) plus disposal ($380). We called the owners with the photographs and a fixed change-order before continuing.

Five other items came up: replacing 6 deck sheets at the kitchen sag ($1,140 — quoted in original estimate at per-sheet rate), re-flashing the original brick chimney with copper step-flashing ($1,860 — pre-quoted), discovering and capping an abandoned chimney that had been hidden under shingles for 40 years ($420), rebuilding the ridge vent end-caps to match the slate pattern (no charge — install detail), and salvaging the original copper finial which we cleaned and re-mounted (no charge).

Final invoice vs. estimate.

All change-orders signed in writing before work continued. Final invoice was 7.5% over estimate, well within the 5–10% typical for a tear-off discovering legacy layers.

Drone the roof harder before quoting.

The third layer wasn’t visible from below because the eave detail was so heavily caulked. A closer drone inspection at quote time would have flagged it. We’ve updated our pre-quote checklist for historic homes to require a 4K close-pass at the eaves on every elevation.