 |
I need to construct a concrete pad for a hot tub. I need the top of the concrete pad to be 18" above ground level to fit into the deck plan properly. I plan to dig about a foot into the ground to avoid the majority of any frost heaving (we're 25 miles north of Philly, PA). I will use six inches of crushed stone that get compacted, but my question is, do I pour 24 inches of concrete, or somehow build-up the inner area and only pour the 4-6 inches that is recommended for the hot tub? Any advise?
Is the H tub going to be recessed into the compacted rock? Is any access needed to the underside of the tub for jets, electrical, pipe repair etc. Is the tub free standing or have a lip?Quote:
Originally Posted by sbwolf
Thanks for getting back to me. The hot tub is free standing, and will sit on top of the concrete pad. I will have the access I need for the access panel as I've made a removable section of the deck to get to this area. The main question is about how to construct the concrete pad. Pour 24"? or dig a footer around the perimeter and somehow build up the center area and only pour about 6"?
I wonder why it can't be bond beam posted without having to deal with grade buildup and at least a 3" slab. Concrete is going for a C per yard in some areas. You won't need to remove that heavy decking panel for access. Two 2x8 girders across pier beam posting will support a ton. Then just frame lattice under a rim joist trim. Unless there is a dry rot worry... nm
Calculate total weight then use nmwirez idea, 1 gal of water weights 8.33 lbs, assume average weight for adults at 150-170lbs, then the weight of the hot tube. My 4-5 person tub is about 36 inches off ground on a deck, it is supported by deck and by additional supports right under it.. 2 sets of doubled 2x10's beams and 4x4's posts.
I am in NYS frost line per code is 36 inches. Get below the frost line it can move anything.
Thanks, but I can't seem to get anybody to answer my actual question. I'm not asking about using girders, I'm asking about concrete. Does anybody know if it's a problem to pour 21" of conrete for a pad that's about 7' x 8'?
Quote:
Originally Posted by sbwolf
Sure you can do a direct pour, but if the grade is not compacted and drained properly, that thick slab will compact moist soil conditions even more under the combined slab and hot tub full of water weights. You will have a harder time trying to re-level or shim up the tub at a later time. Nm
You can pour a footing around the edge of where you want the slab to be. Then either pour a concrete wall around the perimeter up to 4" from the elevation that you want the hot tub or make it out of cinder blocks. (If you go a foot into the ground then want 18” above, the walls will be 2.5ft high minus the thickness of the slab on top.) Fill the area inside the square "box" that you've made with compacted dirt. Pour a 4" slab on top of the structure and put your hot tub on top.Quote:
Originally Posted by sbwolf
You need to make sure that you compact the dirt very well to prevent voids and settlement that will lead to cracking of the top slab. Be sure to compact the natural ground below the crushed stone thoroughly as well as the crushed stone.
If you decide to pour the walls I would go at least 6" thick with some steel reinforcement. It may be easier to use cinder blocks, which would also need some reinforcement. Either should work fine though.
JB
JB is spot on for saving concrete and the center fill design. If cinderblock is used, run rebar horizontal with cement filler. For 6" top slab pour bend rebar risers in to slab top area also. This is still going to be a heavy support compared to girder method so as jimbobcooley says... compact, compact to reduce settling. Nm
| All times are GMT -7. The time now is 10:00 AM. |