Aluminum Deck - How to cross mount i beams

Hi I have a deck that currently is near the end of its life and I was thinking about replacing it with aluminum. I live near costal area that gets a lot of moisture so wood rot is a problem. The construction is a joist and bearer construction where the joint is cantilevered 2 ft out and the space between the bearer and my house is 10 feet. The bearer is standing on 10 ft posts mounted on top of a concrete pad. The bearer runs about 80 feet along the north side of my house. I thinking of using a 4.23 x 8 inch Alum 6061 I beam with .53 inch thickness as the bearer and replacing the joists with 3x5 inch Alum 6061 I beams .25 thickness. The smaller I beams would laying on top of the bearer perpendicularly. How would you mount the 2 together?

 

I'm not sure what you are calling a "bearer" maybe a ledger or beam? But... codes have gotten pretty tight regarding deck construction. Check with your building inspections department to see if that method of construction is permitted. My guess, because you are doing something non-standard, they will want your solution professionally engineered.

Welding is a common method of joining aluminum members and 6061 welds easily for aluminum.

 

Welcome to the forums.

Elevated decks require special construction.
I'd imagine you'll need submit a plan to your inspector as well as have the work inspected.

 

Yeah ledger is probably a better term for it. The codes for my area are pretty well spelled out. 12 ft limit from ground to deck floor. Joists must be 2 ft or less apart. Cantilever cannot be more than 2 ft or 20% the joist length. Live weight capacity 40 psf and static weight 10 psf. My deck was inspected 2 years ago when I bought the place and it was up to code but some of the joists were rotten. I will probably go with rivets to connect the post and ledger using a 90 degree bracket but was not sure if the ledger and member could be riveted. I would then spot weld either grating or expanded metal to the top then put pavers across.