What is RTD Plywood?

If you’ve been quoting a roofing job or sourcing materials for a new build lately, you might’ve noticed more suppliers pushing “RTD plywood”—especially in place of the old standby, CDX. At first glance, it looks similar. Same thicknesses. Same stack in the yard. But dig a little deeper, and you’ll see why many builders are making the switch.

So, what is RTD plywood—and should you be using it on your next project?

Let’s cut through the jargon and get straight to what matters on the job site.

Breaking Down “RTD”: It’s All About Quality Control

Unlike “CDX,” which refers to face grades and glue type, RTD stands for “Rated Sheathing” with enhanced manufacturing standards—specifically, it meets the APA’s PS 1-19 or PS 2 structural panel standards with stricter moisture and bond durability requirements.

But here’s the real-world takeaway:

RTD plywood is CDX—but built to tighter tolerances and tested more rigorously for consistent performance in wet conditions.

The “RTD” stamp (often red or black) appears alongside the APA logo and indicates the panel was produced under the APA’s “Rated Stamped” program, which includes:

• More frequent glue bond testing
• Stricter limits on core gaps and voids
• Better resistance to edge swelling when exposed to rain

In short: if your job site gets rained on (and whose doesn’t?), RTD gives you a bigger safety margin than standard CDX.

How RTD Compares to Standard CDX Plywood

Many contractors don’t realize this—but not all CDX is created equal. Two mills can both sell “CDX,” but only panels stamped “RTD” guarantee that extra layer of quality assurance.

Where RTD Plywood Really Shines

Based on conversations with framers and roofers across the U.S., here’s where RTD earns its premium:

Roof Sheathing: The #1 use. With open roofs often sitting days (or weeks) before underlayment goes on, RTD’s reduced swelling means fewer callbacks for buckled shingles.

• High-Humidity Regions: Think Gulf Coast, Pacific Northwest—places where morning dew turns into afternoon downpours.
• Projects with Tight Schedules: Less risk of delays due to warped or delaminated sheathing after unexpected rain.
• Code-Compliant Builds: Some municipalities now prefer or even require RTD-stamped panels for structural sheathing in wind-prone zones.

One Texas roofer put it bluntly: “I used to spec CDX. Now I won’t touch a job without RTD. The $2–$3 extra per sheet saves me way more in warranty claims.”

Common Misconceptions About RTD

1. RTD is waterproof.
Nope. Like CDX, it’s water-resistant, not waterproof. Still needs proper roofing or siding coverage.

2. RTD is a different material.
It’s still softwood plywood (usually Southern Yellow Pine or Douglas Fir). The difference is in manufacturing control—not composition.

3. All ‘Rated’ plywood is RTD.
Only panels with the explicit “RTD” stamp qualify. Look for it near the APA mark—it’s usually bold and easy to spot.

Should You Switch to RTD?

If your projects involve:

Residential or light commercial roofing
Fast-track builds with weather exposure risk
Clients who care about long-term performance (not just upfront cost)
…then yes—RTD is worth the slight price bump.

For sheds, interior partitions, or dry indoor applications? Standard CDX is probably fine.

But when performance under pressure matters, RTD delivers peace of mind that standard CDX can’t always guarantee.

Where to Buy RTD Plywood

Most major suppliers now carry RTD-stamped panels:

Dongstar or Vietnam Dongstarwood
Local lumber yards (ask for APA-certified RTD sheathing)
Specialty building material distributors
Pro tip: Always inspect sheets for the RTD stamp—don’t assume “premium CDX” means RTD. If it’s not stamped, it’s not RTD.