How should I connect two beams to a post at a corner?

Question

I'm constructing a 15'x20' screened porch. I've completed work up to the footings, posts, ledger, and joists. I'm now ready to install 4x4 posts around the perimeter which will hold 2x4 bottom plate, two 2x8 to form the header beam, and a 2x4 top plate.

My question is two-fold. First, what is the best height of the posts for an open feel? I'm guessing 8' posts should work for a screened porch but I'm not sure if this is the industry standard or not.

Second, I'm not sure how to install the bottom plate and 2x8 header beam in the corner of the porch. When installing the main support posts and beams I was working with 6x6 posts and was able to notch them and place the beams in the notches. However, with the 4x4 posts for the roof I'm not going to have the adequate spacing for notching.

I have seen some examples where the corners will have two posts butted together so is can fully support the header beam coming from each direction. Not sure this is best or not.

I've searched all over for a diagram example but haven't been able to find one. Any help you can provide is appreciated.

UPDATE

This question is for rough framing that will be covered with finishing materials. I'm using Simpson strong ties for the post base and non-corner post tops. This framing is to support a gabled roof with a 4/12 pitch.

Answer 1

Beams typically rest on their posts or trimmer studs. This case is no different, really, and there's no rule that says you have to have a chunk of post running up the height of the beams. I'd miter the beams at a 45 degree angle so that each rests on half the post. Screw them together well and toenail them into the post. It'll look something like this:

8 feet is a typical room height (92-5/8" precut studs with 3 two-by plates), and that's what's normally used for porches as well. Your situation may call for something else, though. It depends on may things.

Answer 2

We now worry about holding beams down as much as holding beams up. A screened porch is a perfect place for a gust of wind to blow in and have no place to go but push up. I think you need a steel connector between the beams and column....and don't forget to provide a steel connector between the post and foundation.

Simpson Strong-Tie makes several connectors for such a condition. The connectors come in "bolted" style, "nailing" style, sized for glu-lam beams, or for 4x or 2x framing material. Also, you can order them for 4x or 6x posts.

I'd go to my local lumberyard and ask for Simpson steel connectors or Google: Simpson steel corner connectors...I'd start with ECCLL666 for bolted 6x material for about $16.00 each or RTC22Z for 2x material for about $3.22 each. Once there, they have other "suggested" connectors you might like...

Answer 3

You couldn't find diagrams because that's not how it's done. The 6x6s should have gone all the way up to the roof.

with the 4x4 posts for the roof I'm not going to have the adequate spacing for notching.

4x4s are inadequate for posts anyway, and only columns with a face width of 5-1/2" (e.g., a 6x6) or larger can be notched. If your question is how do I attach beams to a 4x4 column, I must leave you to your own devices.

I can't think of a situation where you'd need two beams to meet a column; one of them should be a ledger board supported by giant angle brackets, while the beam could be notched and strapped to the column or use the same type of brackets.

Every diagram you'll ever need: Chicago Deck Code, 2011

Answer 4

Question #1:

The height for an "open feel" is a personal aesthetic choice. I had the same desire for a cabin porch, and went with a shed roof sloping down to about 8 1/2 ft. I'm very pleased with the outcome and get regular comments about the airy feeling in the porch.

Question #2:

To support the beams at the corner post: Consider adding 2x4 (or 4x4) shoulders (jack studs) to the corner posts, to give the beam-ends a purchase. That would be less expensive than load bearing Simpson connectors.