Do It Yourself Roof Trusses: Making King Posts

When considering do it yourself roof trusses, it is important to keep in mind the functionality of such construction: to provide more strength than standard stick-framed roofs. The way in which roof trusses are constructed, with their pyramid-shaped assemblage of smaller pieces of lumber fashioned to form a stronger structure available from lone beams or girders, also provides another benefit.

If and when an individual piece or even if several pieces of the roof truss begin to deteriorate, because of the nature of how the truss is built, it is possible to replace the piece or pieces without fearing collapse of the entire structure.

The most important piece, the king post, serves as the main component of do it yourself roof trusses. As the main vertical piece, the king post is one of the more complex parts of the truss, of which all the other pieces of the truss tie into.

First Steps- Laying Out Marks

After going over your plan (which can be computer-generated from measurements taken to almost any good-sized lumber yard or home-improvement store), mark the dimensions and ensure the roof tip is formed by angled edges that meet and match the roof's slope. Mark the tip at the post's center and then, with a speed square, mark angles using this center mark as the starting point.

When making do it yourself roof trusses, you'll want to think ahead and remember that the tenons of the two rafters will be meeting at the inside at the topmost part of the post.

With this in mind, mark a two-inch mortise to bisect the peak and that, when finished, will make the peak look something like a two-tined fork. Just beneath the head, then place angled shoulders for roof rafters, and then take measurements and mark off a two-inch tenon to fit in a beam (known as a 'collar tie').

The Cuts

Using a beam saw for the next step, partially cut the marked angles at the post's top, finishing by turning it over and using a circular saw.

At the post's bottom end, again using the beam saw, partially cut the tenon, and then with the circular saw held a forty-five-degree angle, make partial cuts for the shoulders of the post, utilizing a band saw to finish these cuts. With a chainsaw mortiser, make a square hole through the post's head so that later the post can be rotated around the blade of a band saw.

Move the king post of your do it yourself roof trusses over to the band saw and cut the mortise into the head of the post. Carefully saw into the mid-section of the wood until you reach the square hole you made above with the chainsaw mortiser. Then manipulate the post around the saw blade, creating an exit cut to be able to take out the center wood piece. Finish off the partial cuts made on the shoulders and tenon.

Cleanup and Sanding

With a disk sander and 30- or 40-grit sandpaper, sharpen up the king post's shape and use a chisel to clean up the forked crown. As the final step to making do it yourself roof trusses, use a belt sander to get all surfaces smooth and splinter-free. You're now ready to make the rest of your truss, but you've completed the most important and difficult part.

See Also:

How to Install Roof Trusses