New Deck

Old 05-21-09, 08:02 AM
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New Deck

Hi There,

Building a new low deck/patio.

Its going to be only about 23 inches off the ground (so I can get around the stupid bilaws that wont let me extend my current deck more then 4 feet).

It will be about 12 feet by 12 feet. I am wondering if there is a standard amount of posts I need for this deck? Is 4 (4x4 w/concrete) posts enough? Or should I have 6?

Any help is much appreciated.

Thank you,
Old 05-21-09, 01:52 PM
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Neel, not sure where you live, nor what bilaws you are referring to. If a homeowner's association, you're on your own.
Your posts are generally 8' apart, so if you have one on each corner and one midspan, you should be just fine. Again, I don't know if this extension is attached at a particular point on your existing deck or not, so you can subtract the posts that would be duplicated. Don't embed wood in concrete. Instead pour footings in accordance with your building department and local code/frost line, install Simpson Strong Tie post bases to the concrete pier and attach your wood to that.
Old 05-21-09, 08:27 PM
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Post spacing and beam spacing is determined by what you are using for beams and joists, as well as how far apart the joists are spaced. How many (or how few) posts you use will determine thier size.

If you use 4X8 or larger for the beams you can space the posts 8' apart. A 2' cantilever on each end of the beam will get you to 12' in that direction.

If you use 2X6 joists at 16" O.C., they will span 10', but I would span them 8' and leave a 2' cantilever on each end. That gets you to 12' in the other direction. This is all based on using doug fir for the framing. a different species of wood will have different span capabilities.

Done that way, you need 4 posts that can be 4X4's.

Footing size and depth is determined by where you're at and whether frost is an issue or not. Check with your local bldg. dept. about that.

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