Shelves The four shelves receive dados to accept vertical members. These dados are ¼” deep and 1-1/4” wide with outside cheeks 7” from each end. These dados can be milled a number of ways, in this case a router with a straight cutting bit was used. However, a stacked dado blade can be used with a radial arm saw to make them as well.

All wood workers need to be aware of wood movement when building furniture projects. Failure to consider this important factor can cause wood panels to crack or split.

My high school biology teacher compared structure of a piece of wood with a bundle of straws. The straws represent cells and capillaries of wood. When a tree is growing water and food are transferred up through cells and are carried throughout tree.

Once a tree is fell free water in wood is lost rather quickly but bound water trapped in straw like cell is slower to dissipate. As level of bound water is reduced these straw like cells get narrower in diameter but maintain their length. This is fundamental reason that wood expands and contracts across its width but has almost no expansion length wise.

When working with wood it is very important to allow wood to expand and contract with changes in humidity. As humidity rises straw like cells expand in diameter with opposite effect occurring as relative humidity falls.

Ways to accommodate expansion