Alvas Floating Subfloor is designed to use 9-Lamination 5′ x 5′ x 1/2″ Baltic Birch Plywood Sheets. The 9-crisscross laminations within the plywood makes it very stiff, allowing it to flex both ways evenly. This specific plywood has better integrity and will not delaminate. Regular types of plywood flex unevenly and the layers can become delaminated.
The 5′ x 5′ x 1/2″ size of this plywood is less expensive than 4′ x 8′ x 1/2″ sheets because the length of the wood grain is shorter (5′ long vs 8′ long). We recommend starting with North American Plywood as your wood source, or they may recommend a dealer near you.
Any variation from the Alvas DIY Instructions (included in the Alvas Floating Subfloor Starter Kit) will invalidate Alvas warranty.