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10/20/2017 1:01:18 AM
9/22/2017 12:11:25 AM
Posted: 9/9/2005 5:25:10 PM EDT
I'm building a 16X20 deck attached to a 16 foot ledger that's already on the house. I'll have 6 foot steps coming off one side. How many 4X4 posts ought I have? My estimated judgement right now is 9 total (3 rows of 3). Structurally speaking, and all code enforcement issues aside, what's the normal spacing between support posts under decks....6 feet or so?

I won't be putting a hot tub on it or anything, just lots of people, some patio furniture, grill, and in the winter, some snow.

Just curious, I bought 6 sonotubes today, but in the process of sipping my 3rd Whisky tonight, I'm wondering if I should go with 9...

Hive mind, what say ye.
Link Posted: 9/9/2005 5:34:59 PM EDT

87 POSTS !



sorry, it was just BEGGING to be done, hehe
Link Posted: 9/9/2005 5:40:01 PM EDT

Originally Posted By JB69:
87 POSTS !



sorry, it was just BEGGING to be done, hehe



well, it'd certainly be sturdy enough!
Link Posted: 9/9/2005 5:46:20 PM EDT
Link Posted: 9/9/2005 5:48:33 PM EDT
What size beams and what size joists what size posts? SWAG would be four rows of three on the posts 4x6. Double 2x12 for beams. That would give you a 5 foot joist span and you should be able to get by with 2x6 on 16 inch center.
Link Posted: 9/9/2005 6:03:45 PM EDT
[Last Edit: 9/9/2005 6:04:59 PM EDT by Winston_Wolf]
... A deck on a man's home should be an extension of his very character and imagination, the structure should reflect just that. You cannot compromise on its engineering

... If done right, you will spend more time on it than inside the dwelling

... Don't skimp on design. Define exactly how you want it to look. Detail your materials estimate, lay out your schedule to complete - use your best engineering skills


<­BR>


(or just hire me to do it )
Link Posted: 9/9/2005 6:04:08 PM EDT
I have built many decks and use a girder type system. Don't use 4x4's, use either 6x6's or 4x6 set directly in the ground on a concrete footing.

Notch the top of the post on both sides and set 2x10's the full width of the deck. You probably get away with 1 row of posts using 2x12 joists. Otherwise, I would use 2 rows of posts with the joist cantilevered out at the end.

I am not explaining it well i know. But could take pics of the underside of the deck at my house describing what I am saying. I didn't build the deck, but it is built the way I typically build them.

Send me your email and I'll send you some pics.

Rick
Link Posted: 9/10/2005 4:25:34 AM EDT
The deck itself will have 2X8 joists and 4X4 posts (already bought them). I planned the spacing to be 16" on center. I think I'm definately going to roll with 9 posts, like you guys said no sense in skimping out just to regret it later.

Thanks all, Rick IM inbound.

Link Posted: 9/10/2005 4:40:38 AM EDT
Go to the "pro desk" at your local home depot. They'll help you plan it. They'll know what your local codes call for as far as loading and therefore spans between posts.

Make sure the footings are deep, as frost is worse under a deck than elswhere (because there's no snow cover).

And make sure to flash the ledger board well or you'll have rot problems in your house.
Link Posted: 9/10/2005 4:46:26 AM EDT

Originally Posted By Rodent:
Go to the "pro desk" at your local home depot. They'll help you plan it. They'll know what your local codes call for as far as loading and therefore spans between posts.

Make sure the footings are deep, as frost is worse under a deck than elswhere (because there's no snow cover).

And make sure to flash the ledger board well or you'll have rot problems in your house.



10-4, I did the flash last week so that's all set. I'm rolling with 48" footings to get below that Maine frost line. Re: the Depot, I have to head there this morning anyway for some other stuff so I'll swing by and confirm what I think is the right answer.

Ya know I almost put that ledger board up without the flashing....caught it last minute but at least I caught it. It's my first deck so I'm a little overly paranoid about making the wrong choice. So rather than chance it with 6 posts I'm gonna put in 9.
Link Posted: 9/10/2005 4:48:04 AM EDT
... are you going with composite materials or sticking with conventional wood decking?
Link Posted: 9/10/2005 4:52:24 AM EDT
That's another good point, WW.

I love composite decking. You should space your joists 12" instead of 16" because it sags, but then you'll never have to worry about rot or slivers in your bare feet. (Those pressure-treated slivers especially are a bitch.)
Link Posted: 9/10/2005 5:04:07 AM EDT
I space them 4' on center. My reason for this, if you plan on installing lattice, less waste and cost
Link Posted: 9/10/2005 5:05:58 AM EDT
If it's pressure treated lumber use either stainless screws or Simpson Zmax nails.
Link Posted: 9/10/2005 5:30:00 AM EDT
Hokie...I sent you some pics.

I would not go through the expense of staineless screws. There are coated screws on the market that I have had good success with. Home depot sells them and they have not corroded on me yet.
Link Posted: 9/10/2005 5:39:24 AM EDT
Link Posted: 9/10/2005 6:07:37 AM EDT
[Last Edit: 9/10/2005 6:09:14 AM EDT by prk]

Originally Posted By Hokie:
The deck itself will have 2X8 joists and 4X4 posts (already bought them). I planned the spacing to be 16" on center. I think I'm definately going to roll with 9 posts, like you guys said no sense in skimping out just to regret it later.

Thanks all, Rick IM inbound.




the 4 X 4 's can't be returned for 6 x 6's?


ETA: Good luck finding decent (dry) wood at Hovel Depot
Link Posted: 9/10/2005 8:12:28 AM EDT
4X4's are only "adequate" if you're going 6 feet high with them. Use 6X6's. Run 2X10X16 foot joists out from the house. Your outer band should be a doubled 2X10 or 12. Then run a beam lengthwise down the deck and put posts under that. I've built a LOT of decks - you CANNOT always rely on the guy at the home supply store to give you reliable info. And a BIG +1 on the plastic deck boards. Just be sure to use closer joist spacing than 16".
Link Posted: 9/10/2005 8:24:05 AM EDT
[Last Edit: 9/10/2005 8:35:18 AM EDT by krpind]

Originally Posted By Hokie:

Originally Posted By JB69:
87 POSTS !



sorry, it was just BEGGING to be done, hehe



well, it'd certainly be sturdy enough!



What does post count have to do with anything......someone with 87 posts should be as smart as someone with 40,837 posts.

<­BR>




Seriously we built an 8 X 48 at our farm, and I think we used 18 21 posts.

Edit because I am --->
Link Posted: 9/10/2005 8:57:44 AM EDT
I just checked the last deck I built. It's 12 X 40', with seven 6X6 posts and 2X10 joists spaced 12" apart. The rim joists are 2X12's. Composite decking and vinyl railings. No rot, no slivers, no maintainance and it'll hold a lot of snow
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