Hottub supports

Hi all, Compared to some of the amazing information I have seen here I think this one should be a snap:)

I am looking to support a 8-man hot tub. The tub weighs about 1000 pounds empty and holds 530 Canadian gallons of water. So with people plus a safety factor I figure about 8,500 lbs.

I want to support this on four adjustable points.

Here’s what I have so far….

It has a 90" X 90" footprint and I built a platform 90" square using pressure treated 2X6 studs at 12" centers. It also has a double 2X6 plate at each end. I covered the platform with 5/4"X6"X8’ pressure treated deck boards with 1/4 inch spacing. Two screws at each joist.

This gives me 56.25 sf to support the weight. It works out o be 150 psf…any comments so far on the platform??? I guess this would depend on where the supporting beams were to be placed…read on.

I have four concrete blocks, each 8" X 8" X 16". When viewed from top you see 8x16. I drilled a 1 1/4 inch hole vertical though the

8” and plan to use four 6 inch pieces of 1” threaded rod as the adjusting points. I have placing a steel plate on top of each block (with a hole in it to match the hole in the block) and most of the rod will be inside this hole with it being supported by the shoulder of a nut on the steel plate. I can then use the nut at each corner to jack up or let down the tub.

I guess you figured out what part I am missing…I have not yet figured out what to place between the rods and the platform. I am planning on using two beams. Either wood or steel but because I am getting pretty high I would prefer a lower profile option. I was thinking of using two 4” I-beams 90” long and then weld the rod onto the I-beams 12” in from each side. Then place the beams under the joists about 12” from each end. If I did my calculations right each beam should have to support a weight of 566 plf….comments?

I have two I-beams now but fear they are not really strong enough as they are a lot lighter then some I have seen and I don’t have any specs. The beams only weigh about 5lbs a foot.

I might have access to some 4” beams that are a heavier (about 9 lbs a foot)

So I invite comments on any part of my plans. But being that it is all completed except the choice of the two support beams my specific question would be What is the minimum size of steel beam or wooden beam I could use if I only use two beams and if I support them in each of two OR three places.

Thanks in advance, Kelly

Reply to
Kelly
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Why does it need to be adjustable at all?

BB

Reply to
BinaryBillTheSailor

maybe to level it, if it settles? I got lost reading this one ,seems that it must sound alot more complecated than it realy is.

Reply to
gg

Are you in San Francisco? Are you gonna let ANY wimmin in there?

Steve

Reply to
dipodomys deserti

If that is the reason, then it's the absolutely wrong thing to do. A properly installed tub will not settle. What the origional poster is proposing will cause far more problems than it will solve.

BB

Reply to
BinaryBillTheSailor

I used to have an account that was an apartment project. It was settling. Seriously. They had an outfit from California come in and hydraulically inject an epoxy mix under the foundations. They were able to level it out pretty darn good. That would be a case of leveling after installation. But I agree with you that an adjustable foundation would be an unusual thing. Maybe on a houseboat ................ or a tin can ................

Steve

Reply to
dipodomys deserti

Seems there is some interest in my design. I appreciate all the comments they helped me in my decisions but I still went with most of my original design. So far it seems to be working great! No noticable side to side movment at all.

In case any-one is interested I will describe it from the ground up. I also took alot of pictures so I might share them if any of you are interested email me.

OK started with four holes about two feet square and filled them with crushed rock. Placed an 8" by 8" by 16" concrete block on top of the rock and then a 1/2" steel plate on top of each block to distribute the wieght evenly. the plate and the concrete block have a hole through the center. then I used a 1" rod six inches long and welded that to another steel plate that I lag bolted to the bottom of a 6" by

6" by 8' wooden timber. So now each end of two timbers are have a threded rod sticking out that I slid into the steel plate and blocks. Now on top of the two timbers I placed my 7.5' by 7.5 foot platform and on top of that my tub. Like I said it works great it's semi portable. No piles to pour and as the ground shifts I adjust my tub to keep it level.

Questions any-one? I think some of my other posts replaced by mesurments with some goofy &#t665 symbols sory bout that hope they come across good this time?

Hey if no one questioned the norm or the standard way to do it then we would never invent anything new now would we?

Kelly

Sorry for the poor spelling I am in a hurry and better get back to work.

Reply to
Kelly

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