# Framing deck to support a hot tub



## A&J

Looking for a footing layout and sizes to support a 8 person hot tub. Are 2x6 joists usable in this application?


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## WildWill

I found this, maybe it will help.

http://webcache.googleusercontent.c...d=2&hl=en&ct=clnk&gl=us&source=www.google.com


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## SLSTech

Generally NO & almost every member here is going to refer you to see an engineer. 

Just a little common sense thinking - how many liters at how much weight + 8 people at how many kilos - that adds up pretty quickly


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## [email protected]

The last time I did a hottub deck I used 6 x 6 posts with 12" wide by 48" deep footers. Framed with 2 x 10, joist hangers, and for added support lag screws into all joists.. Decked with 2 x 6. It came out solid as a rock.


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## ScipioAfricanus

There is no prescriptive solution for a deck with a hot tub, you need it designed I think.

Andy.


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## KnottyWoodwork

Do you have the oppertunity to drop it in the deck, instead of on? If not, give those techno posts a look.


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## Clemens

A hot tub platform is normally designed freestanding. (if elevated)
This means a minimum of two beams (2 2x12) sitting on 6x6 (notched) with 20" x 8" footings. Joist a minimum of 2x10 16"o.c. with 2x6 decking.
Joist shouldn't sit in joist hangers but rather on top of beams.
This is common in our area (engineered plans)
You need to see an engineer for plans (like it or not) and give him the specs.
Don't even think about 2x6 joist.
Clemens
www.finedecks.com


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## GettingBy

Knowing the dims of your tub you can figure out how much it weighs using 62 pounds/cu. ft. of water. 
I guess it's a distributed load rather than a concentrated load.
The calc. from weight and dims to a lumber grade & size & spacing is easy but tedious.

E.g., 500 gals x ~8#/gal = 2 tons.
4000#/64 sq. ft. = ~63 PSF dead load.
The Engineering Toolbox website and others have the formulas.

After you build it, check the joist deflection under the tub, L/360 or L/720 or whatever is recommended for decks.

Designing footings can be messy
http://books.google.com/books?id=_m...&resnum=1&ved=0CCIQ6AEwAA#v=onepage&q&f=false
but rules of thumb or testing can get you pretty close, I'd think.

If you hire an engineer you will pay more for his fee but spend less on materials and you will worry less. This, because non-engineers who are not so certain tend to overdesign and overbuild and may still worry about the safety of the finished product.


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## Winchester

train driver


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## FrehouseRemdlin

Clemens said:


> A hot tub platform is normally designed freestanding. (if elevated)
> This means a minimum of two beams (2 2x12) sitting on 6x6 (notched) with 20" x 8" footings. Joist a minimum of 2x10 16"o.c. with 2x6 decking.
> Joist shouldn't sit in joist hangers but rather on top of beams.
> This is common in our area (engineered plans)
> You need to see an engineer for plans (like it or not) and give him the specs.
> Don't even think about 2x6 joist.
> Clemens
> www.finedecks.com


This is how I did my last one, turned out rock solid! I'll see if I can find some pics.


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