Deck

Hi guys,

Newbie here. We're building a DIY deck which will be attached to my trailer. It will be under an aluminum covering which is 16' x 10' x 10' tall (16 feet along the front of the trailer and 10 feet out). The covering is tied to the trailer. There are 3 aluminum support beams on the side opposite the house, but no others. The middle beam is in the deck area, but the other two are outside. We want to remove the middle beam, replace the two remaining aluminum beams with treated wood 4x4's, and place two 4x4 wood beams next to the trailer, leaving the covering still tied to the trailer. The two wood beams away from the house will each have 2 2x6 wood beams attached to the sides of the 4x4 with a 1/2 inch carriage bolt. Do you think this will be enough structural support for the covering without any middle beam?

Thanks,
Bruce

Sory to be blunt, but who knows.
You don't mention the weight or stiffness of the covering.
You also leave it rather confused with your penultimate sentence:
"The two wood beams away from the house will each have 2 2x6 wood beams attached to the sides of the 4x4 with a 1/2 inch carriage bolt."

A photo or two of the existing and a diagram of the proposed would go a long way to clarifying the situation.
Also, you're in the wrong forum.
Additionally, any regulations that might apply here won't apply there, and vice-versa.

When you say "4x4 beams", do you mean posts i.e. are they vertical? Is your problem that you have three post along the length of the trailer (8' apart and 10' from the trailer) and that you want to remove the middle one leaving a 16' span, supported at each end by a 4"x4" post?

If so, then you will almost certainly need to uprate the beam (horizontal) that joins these two posts. Now that you have 16' unsupported, it is likely to sag in the middle. If you are using timber, you'll probably need at least 8"x2" and I think that you should put diagonal braces across the corners (between the beam and the post). These should be joined using a 45 degree mortice and tenon joint although you could use 2 or 3 carriage bolts on each end of the brace if you can't do the joint and are happy with a more "rustic" (hillbilly) look.

Or were you suggesting that you put two 6"x2"x16' along the front, either side of the 4x4 post, using 9" bolts? This could still sag in the middle but it should be strong enough to walk on. You could still fit 4x4 braces using another long bolt through the 6x2s and the brace at the top and coach screws through the sides of the post (pre-drill a clearance hole and use a washer on the screw) and into the brace. You could use some exterior wood glue, too.

Sorry for the late reply and for being so vague. I'm totally new at this building stuff. Instead of 4x4 beams I meant to say 4x4 vertical posts. Thanks for struggling through my poor explanation. The following is the correct interpretation of what I intend to do.


Or were you suggesting that you put two 6"x2"x16' along the front, either side of the 4x4 post, using 9" bolts? This could still sag in the middle but it should be strong enough to walk on. You could still fit 4x4 braces using another long bolt through the 6x2s and the brace at the top and coach screws through the sides of the post (pre-drill a clearance hole and use a washer on the screw) and into the brace. You could use some exterior wood glue, too.

Would 2x8x16 beams be better than 2x6x16? I didn't want the weight of the beams themselves to become an issue.

What would you recommend for the positioning and length of the diagonal braces in the corners? I would need the smallest span, while remaining structurally sound, in order to not interfere too much with the deck.

Thanks for your patience and help,
Bruce