Split boards are easily repaired if you detect the splits before you incorporate them into a piece of furniture. If you notice the split in the wood after you build something, you may have a bigger problem. To avoid the risk of splits, always cut off the last 2 or 3 inches from a piece of lumber before using it.f you notice the split in the wood after you build something, you may have a bigger problem. To avoid the risk of splits, always cut off the last 2 or 3 inches from a piece of lumber before using it.