Replies

1. 
   bearmon | Oct 06, 2002 11:53pm | #1

   32" thick?  That's a typo, right?

   Bear

1. 
   crabbyhammer | Oct 07, 2002 12:09am | #2

   Hello Bearmon,

   No that is not a typo. It needs to be 32(well actually 28" now that the tamped stone is in place) inches thick in so that the jacuzzi comes up through the surface of the deck. Idea's ? Warnings ?

1. 
   JeffBuck | Oct 07, 2002 12:26am | #3

   how about build a regular pad with footer....and build the cribbing out of wood?

   Frame it up and set it on top?

   Just sounds much easier than a big man made boulder...probably cheaper and easier too.

   Is that a possibility? Not sure what I'm missing here.

   Jeff.......Sometimes on the toll road of life.....a handful of change is good.......

1. 
   brownbagg | Oct 07, 2002 02:12am | #4

   really be honest a 4 inch slab will hold the hot tub, a typical concrete is a 3000 mix. that is 3000 lbs per square inch. If you can load a square inch that much I be worry. The problem is settlement of soils . If the soils under the slab will hold withoutsettlement , not to worry. But I know you do not believe me so throw in some rebar. steel is cheap. run #5 everyfoot both way..

    Think about this. The hot tub will weigh about the same as our truck. The total weight of the truck is on 4 tire patch about 10 x 10 inches that is 400 sq inch.

   So a 5000 lb truck on 400 sq inch of concrete which is a 4 inch slab that finisher place wet. is only 12.5 lbs per square inch or 1851 lbs per sq ft The slab hold the truck fine.

   Now how much surface area is holding that tub.

1. 
   Piffin | Oct 07, 2002 04:17am | #5

   That 3000psi is compressive strength, not loading strength. Let's gewt some useable information up here.

   I was kindof shocked to see 32" deep too, wondering what engineer came up with that. I am hoping the stone mentioned is on good compacted soil and not on topsoil. Presuming that to be the case, we know we don't need to fill that whole cube up with concrete. That adds weight. I would pour a footing, lay some block and fill the center of the cube with block or rubble to take up space, and then form again to pour the top slab with rewire in it..

   Excellence is its own reward!

2. 
   55512122 | Oct 07, 2002 05:44am | #6

   I think what crabbyhammer means is the deck needs to be same height as the jacuzzi/whirlpool. So why fill in just set the jacuzzi on a 8'x 8' 4" pad with rebar 2'x2'@ centers and build your deck around that. Or maybe I am also missing something here?

3. 
   eborg2 | Oct 07, 2002 03:53pm | #7

   CH,

   It sounds to me like the top of the deck and the slab he wants to pour need to be at the same elevation.  It also sounds like the deck might already be built and the deck surface is a substantial distance above grade.  Am I on the right track here?

   Why not just drill a series of pier foundations and add extra framing at the tub location?  Then just set the tub on the deck surface.  If you really want the tub on concrete then drill pier foundations and a monolithic grade beam/slab setting on top of them.

   Eric