🏠North Portland Roof Replacement | CertainTeed Granite Gray

What an incredible transformation for this 1921 home! 🏡✨ The homeowner chose CertainTeed Landmark shingles in Granite Gray, giving this historic home a fresh, updated look while preserving its timeless character.

The home had existing 1/4-inch plywood roof decking, which is considerably thinner than commonly used roof sheathing today. The homeowner chose to install new 1/2-inch CDX plywood over the existing decking to create a more substantial surface for the new roofing system.

Here’s why a homeowner might choose to do this:

a. Addressing older construction: Some older homes have thin roof sheathing that homeowners choose to upgrade during a re roof.

b. Thicker roof decking: The original 1/4″ plywood is very thin. Adding 15/32″ CDX plywood creates a thicker overall deck.

c. Better support for roofing fasteners: A more substantial deck can provide better fastening support, provided the new panels are properly secured and the assembly is suitable for the fasteners used.

d. Improved stability: Additional sheathing can help create a more solid, consistent surface for installing the shingles.

A quick note on materials: Standard 1/2″ CDX plywood is technically manufactured at 15/32″ thickness, while 7/16″ is a common thickness for OSB (oriented strand board). The main difference? CDX is made from layers of wood veneer, while OSB is made from compressed wood strands bonded together.

At Portland Roofing Company, we believe in helping homeowners understand their options so they can make informed decisions about their roofs.

Side-by-side comparison of common decking options:

15/32″ CDX Plywood

Premium option in many roofing applications

• Actual thickness: approximately 15/32″ (0.469″)
• Made from layers of wood veneer glued together.
• Generally handles temporary moisture better and tends to dry out more readily than OSB.
• Often holds fasteners well, depending on the panel and fastener placement.
• Usually costs more than OSB.

7/16″ OSB

• Actual thickness: approximately 7/16″ (0.438″)
• Made from compressed wood strands bonded with resin.
• Commonly used for roof sheathing on residential homes.
• Can swell at panel edges if exposed to moisture; prolonged wetting can cause damage.
• Usually less expensive than plywood.

📍 North Portland
🏠 CertainTeed Landmark — Granite Gray
🔨 Quality workmanship from a local roofing company you can trust.

Book your free roof evaluation today at: www.pdxroofing.com or call at 503-490-3994