[akya]

Hello all!

I am looking to build a deck on the back of my house off of the existing patio. I recently got new windows and siding and, as part of the job, I had them install a sliding door on the E side of the patio, and ledger boards under the new door and on the back of the house.

So basically at this point I have ledger boards in an L shape. (the final deck will be 10'x14' and will be 7' off the ground.

Here's an initial layout

The existing patio is held up with the ledger on the North side and 3 posts with a 3 board beam slightly cantilevered (a foot or 2) on the south side.

My question is, do I need 2 posts and a beam under the south side of the new deck (basically held up the same way the existing patio is)? Or could I get away with a single post in the SE corner notched and fastened to the joists?

I live in MN and am trying to minimize the number of deep footings i need to dig. Also because the deck is slightly under 10' wide 2 posts would crowd the area under the deck which will be used as a covered patio.

 

[jlhaslip]

My thoughts would be that you require three posts and piles to carry the long side were the stairs are located.
Based on the layout of the decking pattern your diagram shows, the joists would run left to right, or perpendicular to the decking.
The beam could be lower and have the joists sit on them.
Hangers would be required at the wall.
You would need to review the design with a Building Inspector (or equal) to determine the exact placement of the posts, but in my experience, adding the third post in the middle of the beam would be the best design. The cost to upgrade the beam size to one which would carry that decking load will likely be quite a bit compared to an extra hole when the machine is already on site.

 

[akya]

thanks for the quick reply.

The decking is going the wrong way in the diagram (sorry). Should be horizontal rather then vertical.

There is a paver-patio underneath the planned location everywhere but the last few feet on the south side (that's also where the patio beam is), so it would be beneficial for the beam to be on the South side of the deck if possible. The stairs could be moved if needed.

 

[jlhaslip]

Have a look at this chart to figure out the Joist size and beam size.
Looks like 2 x 10's if you go the 14 foot direction with a double 2x10 beam.
I'm not certain that the Ledger is a really good place to hang the beam from, so I would plan on having two posts/piles under the beam and not hang off the house at all.

Hope this helps.