We are back with another Lumber 101, thanks for all the great feedback from the previous posts!
Do you have a particular subject that you’d like us to cover in this series? To send us a message with your suggestions or questions, please click here
Here is a list of previous Lumber 101 posts:
- How to Avoid Checking and Cracking
- Hardwood vs. Softwood Lumber
- Green vs. Kiln Dried
- Vertical Grain vs. Flat Grain
Today’s topic is Boxed Heart vs. Free of Heart Center (FOHC).
Boxed heart pieces will have the pith (heart center of the tree) within the timber. When a log is milled into timbers, the sawyer will take off the edges (bark/wane) and mill out or “box” the center of the tree. This is the most economic approach to timbers as the whole log is milled in the most efficient way possible.
Boxed heart timbers are more prone to checking due to the shrinkage of the grain around the heart center. We explain “checking” in our last Lumber 101 post if you are unfamiliar with this terminology! Click here: Lumber 101: How to Avoid Checking and Cracking. Keep in mind that checking in a timber does not change the structural properties or durability of the species, it is purely aesthetic!
Free of Heart Center
As the name implies, these timbers are milled without the heart center of the tree. FOHC timbers are less likely to check and warp as they dry, since the grain doesn’t have a heart center to shrink around. These timbers are typically more costly because a much larger log is required to mill the piece of wood.
Timbers graded as #1 & Btr offer great appearance and strength properties. Any knots will be sound and well-spaced, no loose knots or rot allowed. This is a versatile grade that can be used in many kinds of applications. Boxed heart means that the heart center (pith) of the tree remains in the timber when it is sawn. This is done by squaring up a log – taking the edges off – and leaving the heart center. Free of heart center timbers are more costly due to the size of log required, however, FOHC will have less twisting and less serious checking/splitting as they dry.
If you need free of heart center (FOHC), please call us directly. Please note that all timbers are provided green and will air dry over time.