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The Home Smithy
The Home Smithy, Home Builder
Category: Home Improvement
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Hello, I have a decking question. I would like to build a

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I have a decking question. I would like to build a freestanding deck to be placed against my RV. I have plans to build a 12' x 24' deck. My plan was to build this on deck blocks with adjustable supports. My first thought would be at each corner and one every eight feet. So I figured 8 deck blocks. Should I be using more deck blocks?
Also should I use for beams and joists? 2x6, 2x8, or 2x10 ? What should the space be between each joist. I plan to use 5/4 x 6" deck board.
The deck will be approximately 1 foot off the ground. The ground is a thick layer of crushed rock.

Hi. Welcome to Just Answer.

Give me about 15 minuets and I will draw you a diagram of how to build your deck.

Thank you.

Customer: replied 3 years ago.

ok thanks


Okay. What you will want is a pier at each end of the beams set in 2' from the ends. You will need 4 beams spaced evenly with 2x6" joists hangered off of the beams spaced at 24" centers. Then the decking on top of that.

Here is a drawing that will help you see this.

Please let me know if you need additional details or information added to the drawing.



Thank you for the opportunity to serve you.
Best, Smitty
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Mark I just remembered something very important if you are not an experienced framer. When you install the joist hangers use a small piece of 2x6 and put it in the hanger when you set them. Make sure that the top of the 2x6 doesnt stick up above the beam, or hang below it .

Double, tripple, and then check again that the deck beams are square, and level. Nothing looks worse that a deck that isnt square, level, and nice and flat.


Customer: replied 3 years ago.

Thank You. I will do that. I do not quite understand what you mean by (4) beams? I was assuming there would be (2) beams. One at front and one at the back. I am also concerend that a span of 24 feet needs more then 2 deck blocks? The span of 14 feet in the middle, will that not sag?

Also, should the joists be spaced 12" or 16" on center or is that overkill?

Mark, because of the low height of the deck you will not be able to span the full 12' with a 2x6. You would need a 2x8, and that would require a 4x8 beam to hanger it off of. As th size and length of the beam gets bigger the price goes up exponentially.
Using smaller pieces of lumber will save you money and keep the height of the deck down.
Give me a bit and Ill draw a diagram for you from a top view..
Customer: replied 3 years ago.

ok. thanks.

Sorry Mark. I forgot to post the drawing. Here it is.

Please let me know if you have any other concerns.

If not please rate my service.

Thank you.

Best, Smitty

Forgot to include the joist spaceing in the drawing. It is 24" o.c.



Customer: replied 3 years ago.

I understand now.

I am concerned with the 24 on centers? Do you think that will be ok and strong? or would it be better to go 16 on centers? I guess obviously 16 oc would be better, but is it necessary?

Yes that would be much stronger, and would be a good thing if you plan on having a lot of people on it all the time like a restaraunt or nightclub deck. It is overkill if it is just you and your family, and maybe a few friends over holiday weekends BBQing.

The 24" centers have a dead load capacity of 10.7 psi. So that is 107 pounds for every 100 square inches. An average mans foot is about 12" x 4". Thats 48 square inches per shoe times 2 feet per person thats 96 square inches per person Your deck is 41,472 square inches. So in theory you coulf get 423 women the size of my wife (106 wet with combat boots on) on your deck and still be within the tolerances of the wood.


The Home Smithy and other Home Improvement Specialists are ready to help you
Customer: replied 3 years ago.

Hi Smithy,


One thing I forgot to mention. Well I just thought of it. I noticed some people in the area have built a roof system to their deck. This being with 4x4 posts running up and tieing into a roof system. Some with rafters, sheeting and shingles.


Would this system carry that load? It is something I may add in the future.

Sure. It wont tie into the deck though. The 4x4s would have to have footings poured to support the roof.

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