Miter joints are simply explained as the joining of two boards together at a 45° angle. Thus creating a 90° corner. Miters look great when used in finishing a deck and look fantastic when done correctly. The break in uniformed lines created by the deck boards presents a more professional look.
There are 2 common ways to finish and “frame” decking. This is not the same as the frame used to build and structure the deck, but refers to the border around the deck. One way of finishing the deck is to raise the fascia board up to level with the top of the composite boards. This option is cheaper due to the labour needed to do so.
The second option is definitely the better looking option and is called Picture Framing. This requires a single board border surrounding the perimeter of the deck. These boards are joined together using a miter joint.
The only problem with miter joints, is if the framing below is not a perfect 90° angle then joining two 45° cut boards together will not line up properly. There are many different ways to find the right angle, but i was taught a great process by Mark.
By using a regular 1×6 board as a template, I cut a series of boards at 44°, 45° and 46°. I use these boards to help find the right angle for each corner i’m cutting. If all things go according to plan then the 45° boards will line up perfectly. This makes the process very simple. But failing that, i line 2x 46° cut boards up or 2x 44° boards. These boards are usually close but will let me know within a half a degree which way to change the measurements.
Mark taught me a lot of helpful tips during this teaching process. One main take away was that every joint has it’s own story. No two joints are the same. I took this idea about miter joints into the rest of my carpentry work and treat every element of the job as an individual problem with its own solutions.
Miter joints look great when the time and care is taken to make them look professional. The more twists and turns in a deck, the more miter joints there will be, the more character the deck will have. Miter joints are a lot harder to achieve but definitely worth the extra effort. As Mark always says, “You’re only as good as your last miter”. Words I will remember each time i tackle a new corner.