FAQ: Is 3/8″ Plywood Good Enough for My Roof?
We’re often asked about different roofing materials. One question we encounter a lot is this: Is 3/8″ plywood a viable roofing solution?
It might pass code, but that doesn’t mean it’s a good idea. After replacing thousands of roofs, we’ve seen the same pattern: 3/8″ plywood doesn’t hold up. It’s too thin, softens over time, and often needs to be replaced prematurely—especially on second-time roof jobs.
Here’s why we don’t recommend it:
- Prone to delamination: Layers separate over time, especially after moisture exposure.
- Insufficient nail hold: Shingles can loosen more easily due to weaker fastener retention.
- Not load-rated for reroofing: Doesn’t reliably support worker weight or heavier modern roofing materials.
- Fails under stress: More likely to sag or flex, especially between rafters.
- No margin for error: Leaves little buffer for moisture, foot traffic, or minor framing issues.
Our standard: We recommend upgrading to 1/2″ CDX plywood or 7/16″ OSB for strength, safety, and long-term peace of mind.
You’re not just taking our word for it:
Roofing professionals across the industry widely agree—3/8″ sheathing may be technically allowed, but thicker materials like 1/2″ plywood or 7/16″ OSB are the standard for durability, safety, and proper long-term performance.