However, plywood greatly benefits from the low longitudinal shrinkage of wood —layers of wood veneer are glued together with the grain direction of each ply oriented perpendicular to the adjacent ply, which has the effect of restraining most radial or tangential shrinkage within the veneer plies.
Plywood and oriented strand board (OSB), like all wood products, will expand or shrink slightly with changes in moisture content. If the wood structural panels are tightly butted, there is no room for expansion and buckling can occur. That can mean costly, time-consuming callbacks.
Hoping that the plywood will shrink and return to its original shape can be futile. Rarely, if ever, will the plywood return to its original shape and size. The key to avoiding these problems is to plan for the swelling.
Does plywood expand?
The cells begin to expand ever so slightly. This expansion is greatest along the face of the grain of a piece of wood. This means that on a piece of 4 x 8 plywood, you can experience expansion due to swelling across the 4 foot dimension as well as the 8 foot dimension.
Does wood shrink when it dries?
Some wood varieties literally drip with moisture when they are cut. Wet wood is not very stable, and will most assuredly shrink as it dries out. This is the reason why freshly-cut lumber does not work very well for fine woodworking, which requires great precision and fine tolerances.
Another thing we wanted the answer to was: how much does wood shrink?
The amount a piece of wood will shrink lengthwise, called longitudinal shrinkage, is so small—typically about 0.1% to 0.2%—that it is usually inconsequential to the volumetric shrinkage.
How to calculate wood shrinkage and expansion?
Luckily getting ahead of the material and calculating wood shrinkage and expansion is fairly easy – all you need to do is multiply three numbers together. Here’s how to find them. Step 1: Measure the board’s width. ● Know that wider boards expand and contract more than narrower ones. ● Wood expands and contracts mostly across its width.
What are the advantages and disadvantages of plywood?
But plywood has many advantages: • Dimensional stability. Crossbanded layers and balanced construction mean that hardwood plywood won’t shrink, swell, or warp as much as lumber. Its thin plies, lying at right angles to each other, as well as the various core materials available, produce uniform strength both with and across the grain.