Spa Base Preparations

[spahopeful]

I have a J385 on order and will place it adjacent to a deck that is 27" high.   I was planning on using pea gravel with a border of PT lumber as a base.  However, I see lots of comments that cement is probably the best way to go and my Jacuzzi delivery guide also recommends concrete.  I also question how long PT 6X6's will really last in the ground with water splashing on them.  So now I plan to use concrete and have the following questions about concrete:
1.  Should it be level, OR  sloped to allow for drainage?
2.  Would road base be better than gravel for support and leveling of the ground under the concrete?
3.  The J385 has total dimensions of 94", but the base only measures 85" X 85" and I don't want any concrete for chairs or any other reason, is there any benefit to making the pad any bigger than say 87" X 87"?  If I make it 96" X 96" it would seem I may be tripping on the edge of the pad when walking around it for maintenance or filter access.
4.  I'm planning on putting the 4" cement pad so it sits above the existing ground level, thus making the hot tub sit about 15" above the deck.  Does this seem like an OK height to enter the hot tub?  I could try to extend my deck out a little to a lower level, or build the hot tub up if it was really important to have more than the 15" lip, however, either option would be more work for an unskilled carpenter like me.

Thanks for any suggestions you can offer.  I'm still waiting for the chance when I have enough expertise to offer some suggestions.

[spiman]

The PT lumber will last as long as the tub does.

I am going to use pea gravel raised off the ground about 8 inches instead of concrete.

The 15" you talk about should be ok, I am going to put mine about 18" above the deck..............

Stay tuned for pictures in the next few days.....

Same bat channel, same bat place.........

[rick_in_cleveland]

You can also use the plastic spa pads.  I have had my spa on one since the summer of 2003 and through 3 winters and 3 summers it hasn't moved a bit.  At about $300 its much cheaper that concrete and at least so far just as good.

[Brewman]

When you get your PT lumber, try and find material rated for ground contact, if it's offered in the size you're looking for.  If I recall, when I built my deck, there were 2 grades of PT, depending on how deep the pressure treatment was forced into the wood.  If you have the choice, get the higher rated stuff.

[grayson]

My dealer recommended 3/4" crushed rock. I made a "box" with 2 x 12 pt and leveled the stone. I installed a  short lgth of 1 1/2 pvc pipe for a drain and all is well despite cool Maine winter.

[spiman]

Also, not sure what part of the country you are from, but, black locust would work too...........

Check with your local sawmill...............

[HotTubMan]

You can also use the plastic spa pads.  I have had my spa on one since the summer of 2003 and through 3 winters and 3 summers it hasn't moved a bit.  At about $300 its much cheaper that concrete and at least so far just as good.

Rick, what did you do to prepare the site for the plastic base?
Did you dig and poor in gravel/screening/pee gravel?
How old was the house at the time of the tub install?

[rick_in_cleveland]

The house was built in 1941.   The hot tub was set on an area that had a swing set on it for 15 years..  Years ago that spot had the sod taken off it, RR ties set around it and double shredded mulch added under the swing set for 15 years.   We got rid of the swing set, and ties, scrapped off the years of accumulation of mulch.  It was very level and pretty hard packed.    Then I put down 2 inches of construction sand, leveled it with a 10 ft 2x4.  Put down the handi-pad and that was it.  The dealer backed his trailer up to the pad, slid it off onto the pad and it was hot tub city.

Because I didn't want to stand in the grass or snow when getting into the tub I made a frame  out of 2 x 4 s with decking on the top.  This "deck" is on 3 sides and is 24 inches wide along one side, 12 inches wide on the opposirte side and 11 ft x 5 ft wide where we get in.    I used treated lumber put down landscapers cloth and just set it in the ground, laying the frame down first, screwing the 3 sides together and then putting on the top.  Its very heavy and hasn't shifted a bit over 3 winters.

The pad I got at the dealer for about $300,  the "deck" cost about $100 and took about 8 hrs to build.  Its really looks sharp and works great.  If I knew how to attach a picture I'd include one

[spahopeful]

Spiman: How are you getting your pea gravel 8" off the ground?

Does any have any thoughts on whether a concrete pad should be level or sloped for drainage?

[spiman]

Spiman: How are you getting your pea gravel 8" off the ground?
 
Does any have any thoughts on whether a concrete pad should be level or sloped for drainage?

I am just going to extend the gravel edge about a foot on all sides as the deck will be raised and the gravel will be out of sight.

I would not slope the concrete pad for drainage as this will force you to shim the hot tub in order to keep the hottub level.