Why does pre-drilling a hole reduce the chances that wood will split when you put a screw in? Doesn’t the wood still need to expand the same amount?

Question

Why does pre-drilling a hole reduce the chances that wood will split when you put a screw in? Doesn’t the wood still need to expand the same amount?

In: 5

Answer 1

When you drive a nail or screw into wood, the fibers need to compress to accommodate the fibers and the fastener in the same amount of space. Some wood is better than others at compressing and flexing to allow the fastener space, if they can’t compress the fibers will tear and shear causing the crack.

Pre-drilling the hole removes some of the material that will be filled with the fastener. So there is less stuff trying to occupy the same amount of space.