concrete vs pea gravel

[anne]

Hi, another newcomer question:

I plan to purchase a 7-8 foot tub. It will be in the back yard. My plan is to dig out a section of lawn and a little garden, line the area with landscape cloth and then pack it with sand and pea gravel to make a solid, level spot for the tub. It is virtually level already. I'd rather not pour cement, both asthetically and financially, as I can do all of the above without professional help.

Does anyone think this will not be stable enough?

Dealers: are there warranties out there that stipulate ( to this extent) as to the surface a tub sits on? I'm not just haphazardly dumping gravel out-- it will be fully levelled and packed. I got pretty good at this laying a flagstone patio/walkway.

Thanks

[BearBath]

Anne,
I had pretty much this same question several months ago. You might want to look at that thread. http://www.whatsthebest-hottub.com/cgi-bin/yabb/YaBB.pl?board=wtb-hottub;action=display;num=1129246075;start=7

If you use search above, you will also find other comments.

But to answer your question, I had someone else do the work, but I used pea gravel with a layer of stone dust above it. It is very level and met my dealer's concerns about level and solid. It also has the benefit that if any water sloshes over, it soaks in and through rather than freezing on a solid surface. Go for it!

BearBath

[bosco0633]

I think either method is ok, but in  my opinion, why risk it or cut corners.  In my opinion, at least you know that the concrete is sturdy and will in fact support the tub over time.  I would hate to have to drain and refill gravel down the road due to sinking or what not.

Just my opinion

[ssbraun]

You can dig out the area where the tub will sit, build a "sandbox" out of treated lumber, fill it with unwashed 3/4" crushed gravel.  Backfill around the sandbox after staking the sides to prevent bowing. You could also lay a treated lumber 2x6 "floor" on top of the gravel surface.  My dealer has done "hundreds" like this with no issues.  The key is that the surface below should be "undisturbed soil" (not excavated for several years prior)  so that sinkage will not be an issue.  My $.02.

[jsimo7]

You will have this tub many years. 5yrs from now you will be happier with concrete. no chance for sinking or unlevel base and no chance for problems with the tub due to unlevel surface.           my 2cents

[Hot Tub Guru]

Make sure you check with the manufacture on the warranty for placement of spas.  

This is straight from www.arcticspas.com about there Forever Floor that can be placed on bare ground.

Already renowned for our sturdy wood floor, standard on every Arctic Spa, our engineers decided to raise the bar yet again by developing the Forever Floor®. Composed of hand-rolled fiberglass composites, this floor is impervious to moisture, pests, and time. It completely eliminates the need for foundation materials like concrete, decking, or blocks! Just set it on the ground, hook it up, fill and use...installation has never been easier and your floor will last forever in any conditions. In addition, your portable spa is now truly portable. If you move spa locations in your yard or if you move across town, the foundation comes with you.

[Brookenstein]

We dug out/leveled out an 8x8 area, then put pavers down as a border.  Filled it with about 20 bags of sand from Home Depot.  Tamped it down, then put a portable pad down over the top.  Our tub is in the middle of our side yard and our entire back yard is already concrete (but not level and no room for the tub).  We didn't want more concrete.  It took us about an day to do the whole thing.  The pad we used is less than ideal visually, but since my tub was smaller than 8x8 I am able to put some rectangular planter boxes on it to hide the pad.  I also put a second border about 18 inches away from the 8x8 border and planted ferns that will grow up and over to hidethe pad some (on the other sides) in addition to white rock so I have an area I can stand on to put the cover on/off and put the chemicals in without standing on my plants.  Anyway it worked well for us given the situation.

[hottubdan]

I can't speak for other warranties, but for Hot Spring and Tiger River, midsize spas, gravel pad is no problem.  I agree with ssbraun regarding crushed rock, also known as driveway shale.

We actually prefer/recommend that method.  Over time, concrete patios tend to crack and shift with expansion and contraction, heat and cold.  Gravel pad is more forgiving.

Some manufacturerers have pre delivery guides you can download or get from dealer.  They address such questions as base and electrical requirements.

Dan

[Bill_Stevenson]

Anne,

I need to put my engineer hat on here for a minute.  Nobody has mentioned it, but the climate is an important consideration when trying to choose the best foundation for a tub.  In  general if you live where the ground freezes in the winter, the foundation must be deep enough to be below the freeze line in order to ensure long term stability.  Deeper is always better.  Think of it this way:   You would not want the pad to shift or move underneath the spa.  This is because if it did, the spa could be damaged if it were full of water.  Since concrete moves less than gravel due to freezing and so on, it is generally considered a more stable foundation.  But on roadways and such the foundation for the asphalt or concrete is - guess what - crushed rock and gravel!  

Again, find out how deep is deep enough.  Your friendly local building inpector should be able to tell you what you need to know.  you might also ask your spa dealer.  Personally, I like crushed rock and gravel because it promotes better drainage and minimizes the impermeable footprint on your lot.

Regards,

Bill

[loneoak]

What brand of spa did you purchase?

We bought an Arctic spa last fall and just removed some grass and placed it on the dirt.  It has sunk a tiny bit at one end so you can tell the water line is not even all around.  We plan to level it in the spring.  We live in Canada and it gets cold here in winter.

The main reason for us not pouring a pad was the fact that we were unsure of where we wanted the spa to be, and we wanted the option of changing the location at a future time.

The other concern was $.

Hope this helps.

Astrid.