Someone recently handed me a piece of engineered flooring with a ¼” wear layer and a ½” plywood backer and asked me what I thought of it. The distributor was proud of this hefty wear layer, but what they really have is a floor with a greater potential of failure.
The reasoning behind the “wood on plywood” design is that theoretically, the strength of the plywood will overcome the movement related stresses in the solid top layer. The thicker (and wider) the wear layer is, the more it performs like solid lumber, and the increased stresses generated by its movement are pitted against a thinner plywood backer. This movement can result in the forces of the wood overcoming the ability of the plywood core to suppress them, leading to checking, cupping, crowning, and in the worst cases, delamination.
This photo shows delamination of the plywood. The force was enough to rip the plywood apart internally. This photo is from an apartment in New York City, this past winter.
Virtu’s 3-layer “True Balanced Construction” (seen in the above photo) effectively creates a floor with plywood’s stability, and without the troubling element of an unbalanced top layer. Virtu utilizes the same species for the top and bottom, creating a balanced board, just like plywood. The top layer thickness in Virtu is engineered to provide a wear surface and useful life equal to a ¾” solid wood floor, with enhanced stability and reduced movement, and of course, unsurpassed beauty.
THE TAKEAWAY: A wood layer adhered to plywood is already unbalanced. ‘Beefing it’ up makes it dangerous.