Size of Slab

[ggggg]

The foot print on my soon to be delivered Caldera Niagara is 7' 5". I plan on having a slab poured for the tub only (no walkways or patios). The base of the tub is inset a bit from the cabinet, so should the slab just fit the base so rain will shed from the cabinet and fall past the slab or am I being way too picky?

P.S. The Caldera manual states that the slab should have a slope of 1" for each 10'. Is this normal or are most slabs dead level?

Thanks

(I will be glad when the buying process is over and the soaking process begins)

[ebirrane]

A slight slope will keep water from pooling at the base of the tub.  It isn't that much of a s;ope so you are probably fine either way.

Slabs that are only 4" thick and have 1" exposed will get water running underneath them (which is what the drainage rock is for) but, being paranoid, I wouldn't exacerbate any erosion with hot tub water.  I'd make the slab bigger and have that excess water stay on the slab and evaporate.  Assuming the base of the hot tub can handle the moisture.

Depending on where you are, where the water table is, whether your ground is settled or not, whether you are on a slope, blahblah floating monolithic slabs can be tricky. It's good that you are contracting out, but I remember when I shopped around and I got estimates for a 8'x9' slab that varied from $800 to $1600 in MD.  The $1600 proposals were technically sound, the $800 were *not* in my opinion.

We would up with 6" concrete with 8" footers, 1/2" rebar reenforcement and a vapor barrier. All over about 2" of drainage rock.  Some people put a grounding bar in the slab (we did not).  Some also put the conduit in the slab to make things look nicer (but this makes it hard to move the conduit later.  

-Ed

[mhraracing]

Needa - I plan on purchasing the sister to the Niagra - the Geneva and I am building a concrete pad as we speak. I am doing it myself - so It will turn out exactly how I would like it too. I would have to agree with ebirrane and say go with a bigger slab.  - The extra space along side of the spa - will keep you from having to walk on dirt - stone or whatever is around the outside of your slab.
Im not a concrete expert - nor do I play one on TV - but I have researched alot and spoke to a bunch of masons...this is what Im doing.  
Building a 12X12 pad - with a 3 inch 3/8 stone base with 1/2 inch of stone dust on top of the rock. Tamped it down - Then put 14 sections of 10 ft 1/2 re-bar tied together to form a tic-tac-toe pattern - then on top of the re-bar I am putting 3 sections of 4 foot wide by 12 foot long wire mesh. When all is said and done - having 5 inches of concrete poured. - Also I have laid the forms to have an 1/8 of an inch drop per foot.
This should more then enough for a spa - as most garage floors are only 4inches thick with no rebar.
I must admit - Im not an expert - and this maybe overkill - but since I am doing all the work myself - I am using all the means necessary to ensure a safe place for my new spa!!

I hope this info is usefull.

PS - My back is aching from all the shoveling - cant wait till the spa gets delivered.

[autoplay]

Sounds like overkill to me NHRA  At least,you will rest assured,that your spa and pad will withstand an earthquake rated up to an 11 on the rikter scale

2"s  P gravel.....rebar and/or 3" wire mesh.......4+"s of concrete. 1/8" of pitch per foot is ballpark.  Typically specs are 1/4 per foot on exterior applications......but that's also in consideration of long grades.