Using common swing brackets for use with 4- 4x4x8 posts and 1- 4x6x10 beam, at what angle do I cut the bottom of the 4×4 posts to sit flush on the ground?
DIY Swing Set. Need angle measurements
measurementswing
Related Solutions
There's nothing wrong with screwing the door to those two lips on either side. Depending on the weatherstripping on the bottom of the door, it should fit right up to the cement bottom, or top of that sill. Adding an additional "header" piece should not pose much of a problem. It could even extend a bit below the existing one if necessary for a good fit. Hardest part will be cutting those two angles. A saber saw will do the trick if you don't have a miter saw.
You want the post and beam to have the same width dimension. Although you're trying to recycle, it's best to build this with a 6x6 beam and 6x6 posts. It will be stronger and look nicer anyways. Attach them together with the Simpson LCE4 seen below. A total of 4 of them will be needed and each of them will need (14) 0.162 x 3 1/2 into the beam and (10) 0.162 x 3 1/2 into the post.
Best Answer
Without knowing the design of the brackets this is impossible to answer, but rather than calculate angles using trigonometry, there's an easier way:
Assemble it, and sit it on the ground. Then use an offcut of 4x2 or whatever, laid on the ground next the posts to mark a line parallel to the ground on each one. Then take it apart, cut them, and re-assemble.