deck or crushed stone under tub?

[ZzTop]

My only complaint with using gravel or pavers is the problem of ants and other bugs living in the gravel and sand which can sometimes cause problems.  A concrete slab is still the best long term solution IMO.
Regards Zz

[Zep]

re: slab it would be too costly

[size=14]$400-$600 is too much?

I like my solid slab...but I am sure
there many ways to "skin a cat". [/size]

[hottub.pool_boy]

Boy, those are some great pics from anne and TN. Nice job!
Styx-pea stone is round, so it will forever move, it doesn't lock up like a 1/2-3/4" sharp stone will. Can also put stone dust in with sharp stone, further locking it up. I beleive sundance requires a slab or deck. HS grandee or visit should be on a slab or deck. All others in HS and Tiger line are shimmable or can go on gravel bases. Many times we level (3) 6"x6"x8' pressure treated Railroad ties at no chrge right on the delivery of the spa. New spa owner loves it because there's no prep for the base. $100.00 for the wood, we pick it up at the lumber yard and level them for free.

[Styx555]

for those that did their own concrete pad, how difficult was it? Could someone who knows little and has no experience easily lay down concrete?

[hottub.pool_boy]

First tip, don't mix bags! Most areas have "BATCHING" trucks who'll mix and place what you need on site. If they can't get the truck close you'll have to wheel barrow it. Or pay the minimum for the big truck to come. I post more if spa owners don't contribute. Gotta go, shopper in the store.

[TN__HOT_TUB]

First tip, don't mix bags! Most areas have "BATCHING" trucks who'll mix and place what you need on site. If they can't get the truck close you'll have to wheel barrow it. Or pay the minimum for the big truck to come. I post more if spa owners don't contribute. Gotta go, shopper in the store.

Ggood idea to see if you can get a concrete truck....especially since you might need 100 bags.

[Styx555]

A few questions for those who did the PT wood, crushed stone.

1.) I'm concerned that 2*4 will nbot hold in the stone as well as 4*4. However many here used 2*4. Is 2*4 sufficient for the weight load?

2.) For those who made a wood box, how did you ensure the box did not move? Did you drive metal stakes thorugh the wood into the ground or did you just nail the four corners together, or both?

3.) A few mentioned that the tub can sit directly on the stone and I can "shim" it. What does this mean?

[Chas]

I'm considering either a Sundance or Hotsprings. Slab is something we are not considering as it would be too costly. With either of the above 2, is the crushed stone/sand possible?

As was posted above, the HS Grandee and Vista should be set on a slab.

All the other HS models do fine on gravel beds.

I also agree that pea gravel tends to move more than DG 3/4" rock. You can take care of that by simply boxing it in tightly.

Also - no matter which type of stone you use, plan on the spa settling a bit when you first fill it. I have found that it may settle just right, or just wrong. But once that happens, you can empty the tub, adjust it a bit, and then refill for years of trouble-free use. It's just very nice to have this all happen BEFORE any decking is built around the tub...

 8-)

[TN__HOT_TUB]

A few questions for those who did the PT wood, crushed stone.

1.) I'm concerned that 2*4 will nbot hold in the stone as well as 4*4. However many here used 2*4. Is 2*4 sufficient for the weight load?

2.) For those who made a wood box, how did you ensure the box did not move? Did you drive metal stakes thorugh the wood into the ground or did you just nail the four corners together, or both?

3.) A few mentioned that the tub can sit directly on the stone and I can "shim" it. What does this mean?

In making my box frame, I used 2x6.   I secured the box frame with metal corner brackets & long wood screws.  Additionally, I drove some metal stakes along the sides.

I back filled with some dirt and gravel.

[Styx555]

A few questions for those who did the PT wood, crushed stone.

1.) I'm concerned that 2*4 will nbot hold in the stone as well as 4*4. However many here used 2*4. Is 2*4 sufficient for the weight load?

2.) For those who made a wood box, how did you ensure the box did not move? Did you drive metal stakes thorugh the wood into the ground or did you just nail the four corners together, or both?

3.) A few mentioned that the tub can sit directly on the stone and I can "shim" it. What does this mean?

I'm still looking for info on what "shim" means?

[Chas]

You can shim a spa which is sitting on a slab. You cannot shim a spa which is placed on gravel.

I use plastic shims and/or cedar shims to level spas - bu you cannot shim a Grandee or Vista. Those, according to the maker, should be set on a slab.

[blakley33]

Shim is when you have maybe a 1/4 or 1/2 inch difference in once side than the other, you use a little thin piece of wood and shove it under the side that needs to come up.
Just makes it easy to get everything level.

I used 2x4 box frame that was about 6 inches bigger than my tub and put pea gravel down and tamped it in really well then I put about 2 inches of sand down and tamped that really well Once my tub was brought out they put down a spa pad, which I am sure most of you know is a 2inch or so hard plastic base that comes in 3pieces and is set down for a nice smooth surface then the tub is put on that. It has worked great.
I then paved all around the tub right up to the frame.

[Reese]

I'm still looking for info on what "shim" means?

In this case, "shim" refers to inserting material under one side of the tub to level it.  As previous posts have indicated, that is only appropriate for a few tubs due to the stress that hundreds of gallons of water exert on the frame and shell.  

By your questions, I'm guessing you do not have a lot of construction experience.  Given the investment you are making in a tub,  the extra money to have a professional assist you in preparing the site would be money well spent.  You said a slab would be too much, which surprises me.  If you are willing to spend several thousand dollars on a spa, why balk at a few hundred more to set it up correctly?  Did you get more than one quote?  Have you considered other options to a rock base?  A 10X10 PT ground level deck would be easy and inexpensive to put together.  Bakely33's spa pad idea is also a good one.  

Your dealer should be able to assist you in deciding what base the tub you are purchasing requires, some will even come out and look over your site and make suggestions.  They may be able to recommend someone who can prepare the site for a reasonable fee.

[dkersten]

When I purchased my tub a couple weeks ago, I was still waiting for my neighbors fence company to put the fence up between our properties, and couldnt pour a slab before then.  The fence went in yesterday finally, but I called the concrete guy I had lined up and all of a sudden he is busy for 3 weeks.  After calling around, I found that it will take a minimum of 2 weeks to even get a contractor out to pour the slab, and then there is cure time to think about.. should wait at least a week, 3 or 4 days at the minimum.  

A 9x9 slab 4" thick is exactly one yard of concrete.  The contractor quoted me $330 since it is a basic square, nothing special.  My problem isnt cost, its time.. My tub will be in on Monday, and I dont want to wait another month for it.

The ground I am putting the tub on is currently not level, dropping 5" over 9 feet.  The HS dealer recommended 3 railroad ties leveled.  The TigerRiver I bought can be shimmed, so as long as there are 3 beams under it it will be good.  I am taking it further and going with 2x8 PT joists at 16" centers, putting 3 concrete pier blocks starting at the first joist at 16" in, and every other joist after that (total of 9 concrete blocks).  The side that rests on the deck will start at ground level with the 2x8 joists resting on the concrete blocks, and the next 2 courses of blocks will have short 4x4's bolted to the joists with 1/2" carriage bolts.  This way I can level the blocks at the intervals but not have to level the entire area.  The ground has been undisturbed for 40 years, and was scraped 2 years ago of any sod, and has had weedmat and gravel on it since then.  The soil is clay, and hard as a rock.  

I figure the ground wont settle as long as I dont try to build it up for the frame, but rather dig down a little to level the pier blocks.  If I went ahead and poured footings, I should technically wait a week for the concrete to cure well before putting weight on it.  There are cable, phone, and gas lines running under right in the vicinity, as well as a drip irrigation line, and this is next to a big tree and there are a lot of roots as well.

The way I see it, I could do it the best way, which is a concrete slab, and wait another month to use my hot tub.  Or I could pour footings, which would have to be dug out amidst the roots, cable, phone, and gas lines, and still have to wait a week before I could even construct my frame to sit on the footings.  Or I could rely on the solid ground that hasnt moved in at least 40 years and take a chance on some settling.  Crushed stone might work but I worry about the crushed stone shifting because of the drop in elevation, and I dont have a way to trim it out as it will sit above grade.

I will also be attaching one end of the frame to 2 of the 4x4 fence posts that are set in concrete at the end where the ground is lowest.  That end wont have any weight from the tub on it though, and my thought there is that if we get some very very heavy rains or snows here (by some miracle), and the ground softens up, the framed platform cant shift because it will rest against the fence posts that are set in concrete 2 feet down.  

I dont have a specific answer to the question, but I hope sharing my similar dilemma and current potential solution would at least add some insight.  Concrete is not very expensive, and a solid pressure treated base will probably end up around the same price in the end.  The downside to concrete is you either have to go buy 60+ bags and mix it yourself after putting down a good crushed gravel base and building a form, OR you have to rely on a contractor to get to you in a timely manner and get the slab set up and poured.  Then you have wait time for curing.  If your tub wont be in for 2 or 3 weeks I would see about getting a concrete guy out.. around here (Montana) a yard of concrete will cost about $150 and the labor will be around $150.  Not bad considering its the best solution if it works for you.  Building a basic frame and pouring in crushed gravel would be cheaper though..

By the way, in my case I decided I wanted the tub to have about 12" of lip over the deck it rests against, so the frame idea works better in that respect for me (its 13+inches thick) than the concrete pad which was only going to be 4" thick.

[Styx555]

the cheapest I have been able to get thus far is $14 a square foot, which for a 10*10 pad, 4 inches thick is running me $1400 CND. I find that a bit expensive. I have called a few places and that's the best price yet.