I'm thinking about putting a portable spa inground. I'd have a cement pad
with block and morter walls. I figure 40" of clearance to the ("back")pumps/heater/etc. I will install a gravity type drain under the cement pad for any drainage/leakage. Am I crazy to do this? I don't hear about this type of install very often. I live in the Phoenix area.

If you're talking about an install where you've got basically 40" space around the outside of the tub to the walls of the in-ground installation (or more) then it sounds like a plan. But I recommend TWO drains from this thing, not just one.

You're not crazy, but just be extremely realistic to rain/flooding/service concerns in the future. A mistake now could cost you later.

Hi
I am new, and found the site very helpful on spa's and hot tubs.
I was given a hot tub by my neighbor,that is moving and doesn't want to lug this thing around. The question is I have a place to put the hot tub,
but the concrete pad is not level. The patio pad is where I want to put it,
however the slope on the 24' X 16' has a 1 1/2 inch difference,which I guess was poured to allow for water run off. Since my hot tub is 84"X58"
Can I shim up the one side which would mean a 34" wolmanized piece of lumber to level the hot tub out. Then I can stick heavy foam under the skirting to prevent creatures from living in there.?
Thanks in advance

If you have 1 1/2" over 24', thats only 1/16" slope per foot. If you put the lenght of the tub (84")in the length of you patio(24'), you should only be off by less than 1/2" (84" X 1/16" per foot=.4375")side to side, not much to worry about.

Actually the 1 1/2" slope is on the 16' part.
Thanks

In that case it is 1 1/2" divided by 16= .09375 per foot slope X 7' (length of tub)=.65" total slope over a 7' tub. If you use the 58" side it would be .09375 X 4.83' = .45", still not enough to worry about

Thanks a million Jim........Great site !!!