Why do we need to dry flooring?

Lumber for flooring needs to be dried to prevent the boards from expanding and contracting. If you have ever noticed a dead tree standing in the forest, the trunk shrinks as it dries out... and the bark is left loose.

Trees expand as they absorb moisture, and shrink as the moisture leaves. They do this primarily through the end grains. Every type of wood expands and contracts at a different rate.

If a tree is milled into lumber and air dried for a few years it may get down to about 13%. When first milled the moisture content can be as much as 55%. We take it down to 6% because we have found that to make the most stable floor. This is the same moisture content that we use for furniture.


In this photo the wood was put down wet, and it was full width ship-lap boards. No, we didn't make this floor, it is likely about 120 years old. I'd love to see if anyone can guess what type of wood it is made of. It is the only one I've ever seen.
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This floor was typical 5" tongue and groove pine flooring available at any lumber yard. It is often leftover of lifts from different mills, not straight and rarely ever less than 8% moisture content. We mixed the stain to create a pleasing color.
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This wide plank pine flooring was dried, milled and installed by us. I am sure you can see the difference in the size of the cracks. This is a 3 year old floor made of pine just like the last one.

You may find pine flooring "cheaper" however it may be air dryed. So once you lay the floor after some time it will shrink. So don't be careful when you find deals on cheap pine flooring.