Join Date: Nov 2012
Location: Clovis, California
What length screw for joining 2 x 4's together?
A 2x4 is 1-1/2 inches x 3-1/2 inches. If you're joining them face to face, that's 3 inches thick. A 3 inch long construction screw is ideal, but if you sink the screw head below the surface too far, the tip will blow out the other side. A 2-1/2 inch screw only goes into the 2nd 2x4 halfway, giving you only about an inch of material for the threads to bite. I've thought about going with 3 inch washer heads to keep from sinking them too far, but I thought I'd ask you guys what you thought first.