Putting an Intex Pool on a Deck

[mcsands59]

My wife and I bought our house in 2015. The previous owners built a deck and installed a large 7.5'x7.5' Caledera spa on said deck in 2006. This past winter, after 14+ years in operation, the hot tub died, and we had it removed a few weeks ago. Now, we're left with a large empty area on our deck.

My wife suggested that we get a 10' x 30" pool to replace the hot tub, but I'm a bit apprehensive. In my head, the specs all work out, but I'm looking for advice. Here's what I know so far:

1. The previous owners built the deck with the weight of the hot tub in mind. The portion of the deck where the hot tub stood uses sistered 2"x10" joists at a spread of 12". The footings are underground (so I don't know their dimensions), but the posts going into the footings look to be at least 6" x 6" at a spread of 4 - 6'. The deck comes 14' out from the house, and is laid into the ground until about the 8' mark (where the ground begins sloping down into the valley behind our house).
   
2. The previous hot tub had a dead load of 115 psf (7.5'x7.5' base with 500 gallon capacity plus cover and people. The pool, when filled to 24" will be about 125psf including the 40lb structure and people. We don't plan to fill it more than 20" because we want to make sure our toddler can stand comfortably in the pool while using it, so, at 5psf per inch of water for the pool dimensions, we're talking 105psf, which is less than the hot tub.

While the pounds per square foot will be less than the hot tub that was there previously, the true weight will be about 3100lbs more. Can the deck support this additional absolute weight?

Thanks in advance!

 

[CraigStu]

Would there be any way to remove a portion the deck so the pool sits on the ground?

 

[GoodStuff]

Your calculation are not 100% accurate

Pi x r^2 x h x 7.48= gals

3.14 x 5^2 x 2.5 x 7.48 = 1468 gallons

1468 x 8.35. = 12257 lbs

12257 / 78.5 = 156.14 lbs/ sq ft not including structure

500 x 8.35 / 56.25 = 74.22 lbs/sq ft not including structure before

You are more than doubling the load on your structure




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[mcsands59]

Your calculation are not 100% accurate

Pi x r^2 x h x 7.48= gals

3.14 x 7^2 x 2.5 x 7.48 = 2877 gallons

2877 x 8.35. = 24024 lbs




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My calculations are fine.

I don't know where you're getting the "7" or the "2.5" in line two of your math. The pool has a 10' diameter, so your 7 should be a 5. And, as stated in my initial post, we're only filling the pool to 20", so your 2.5 should be 1.67. The math then works out thusly:

3.14 * 5^2 * 1.67 * 7.48 = 980.6 gallons

This 980.6 gallons weighs ~8200 lbs.

Moreover, no 30" pool (I'm guessing this is where the "2.5" came from) is ever filled to the tippy top. The specs for the Intex pool say the max fill is 24" with a wall height of 30".

 

[mcsands59]

500 x 8.35 / 56.25 = 74.22 lbs/sq ft not including structure before

You are more than doubling the load on your structure




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As stated in the original post, the Caldera manufacture's spec says the dead load of the hot tub is 115 psf including hot tub dry weight, 500 gallons of water, and people. I'm unable to post the PDF owners manual because of forum rules regarding post count, but Google 2006 Caldera Utopia Niagara hot tub.

If you're not going to read the original post in its entirety, please don't reply.

 

[mcsands59]

Would there be any way to remove a portion the deck so the pool sits on the ground?

Unfortunately, that's not an option. Without the deck, my backyard slopes about 10 degrees from front-to-back after 8' from the back of the house. Because the pool is 10' diameter, there's not enough room to put the pool directly on a level ground without the deck.

 

[honcho]

I'm not a structural engineer but I'd consider obtaining a professional assessment of the deck, as built and its current condition, to determine the acceptable load limit. Yeah, it's money and effort you probably don't want to spend but peace of mind is priceless.

 

[GoodStuff]

I read your original post. I am a GC by trade, and have built hundreds of custom decks to varying specs.

Water moves. If we use your calculations, the structure will hold. Consider ********** the support post at least. Trying to err on the side of caution. Hot tubs are one thing, but pools on a deck are another creature


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