Can You Put a Metal Roof Over Cedar Shake?
Quick answer
You generally should not install a metal roof directly over cedar shake — the shakes are uneven, and old wood traps moisture and rots beneath a new roof. The right approach is to remove the cedar shake, add solid decking and underlayment, then fit lightweight metal shake shingles that restore the look without wood's fire and rot risks.
Can you put a metal roof over cedar shake shingles?
In almost all cases, no — and it is different from going over asphalt. Cedar shakes are thick, uneven, and often laid on spaced battens (skip sheathing) rather than a solid deck, so they do not provide the flat, continuous surface a metal roof needs. Laying metal straight over them also seals aging, moisture-prone wood beneath the new roof, where it can continue to rot and even remain a fire hazard. The correct, standard approach is to remove the cedar shake first.
Why shouldn't you roof over cedar shake?
Three reasons. First, the surface: uneven, curling shakes telegraph through and prevent proper, flat installation. Second, moisture: covered wood traps humidity and keeps rotting out of sight, which can damage the structure. Third, the substrate itself: because shakes typically sit on spaced battens, there is no solid deck to fasten a metal roof to. Add the retained fire risk of leaving combustible wood in place, and removal becomes the clear best practice rather than an optional extra.
How do you replace a cedar shake roof with metal?
The cedar shakes are stripped off, and because they were likely on spaced battens, a layer of solid plywood or OSB decking is installed to create a continuous, sound surface. A high-performance underlayment goes down next, followed by the metal shake shingles and all the flashing at valleys, walls, and penetrations. The result is a properly built roof assembly — solid deck, underlayment, and lightweight metal — that keeps the cedar look while shedding wood's vulnerabilities. It is work for an experienced metal-roofing crew.
What are the benefits of switching from cedar shake to metal shake?
You keep the rustic look and lose the liabilities. Metal shake ends the rot, moss, splitting, and insect damage that plague wood, and it is non-combustible and Class A fire-rated — a major upgrade in wildfire country and a frequent path to easier, cheaper insurance where wood shakes are surcharged or refused. It also stops the constant treating and sealing cedar demands, lasts 50+ years instead of 20–30, is lighter, and carries a transferable lifetime warranty. For cedar-shake homes, it is often the ideal replacement.
Frequently Asked Questions
Can you install metal roofing directly over cedar shakes without removing them?
It is not recommended. The uneven shakes prevent a proper flat installation, they usually lack the solid deck metal needs, and covering them traps moisture and leaves combustible wood in place. The right method is to remove the shakes, install solid decking and underlayment, then fit the metal roof.
Do you need new decking to put metal over a cedar shake roof?
Usually, yes. Cedar shakes are commonly installed on spaced battens rather than a continuous deck, so once they are removed, a solid layer of plywood or OSB is added to give the metal roof a sound, flat surface to fasten to. Your installer will confirm what your roof needs after inspecting the existing structure.
Is replacing cedar shake with metal better for insurance?
Frequently, yes. Wood shakes are combustible and are often surcharged, restricted, or declined by insurers, especially in wildfire zones. A non-combustible, Class A fire-rated metal shake roof is far more insurer-friendly and may qualify for a fire-safe or impact-resistant discount, which can make the switch pay off beyond just avoiding maintenance.
Sources
- NRCA — Re-roofing over wood shakes and decking requirements
- International Code Council — Roof deck and re-cover provisions
Explore Interlock Metal Roofing
Last reviewed 2026-07-12 · Reviewed by Scott Plumptree, Director of Marketing