Join Date: Jan 2011
Location: Saint Charles, IL
Joining two GT deck boards to make a mitered joint
I was asked by a friend of mine that is builiding a deck for some help. His railing that he will be installing has a "cap" or top rail that is a 5/4 x 6 deck board laid flat across the top of the 4x4 posts. In the corners of the deck, he was planning on mitering the boards, but has seen that over years, with the exposure to the hot sun the boards shrink, and the miter opens up, even if a screw is put in through the ends of the miter. He was wondering if there was a better way to make this joint. 2 things popped into my head right away.... either a spline joint, or a half-lap miter joint. The spline would probably be the easiest, but what should I use for the spline? Another planed down green treated deck board? Won't it shrink too much? With either one, what type of glue should I use for the outdoor conditions? Polyeurathane glue? Outdoor wood glue?
Is there another joint you would use?
Thanks for taking the time to read this, and I look forward to your suggestions.
I used to be fairly indecisive, but now....... I'm not so sure.