Tundra Set Up

[tnt3]

New to site and new hot tub owner I just purchased a Tundra Signature Series with the forever floor. The question I have is the set up prep The ground I am placing the Tundra on is rather level grass and has been established for 8yrs. I was thinking of placing patio stone 18 x 18 inch to cover the entire ground. I have been told by friends that I have to dig down 6 inches compace ground add gravel and then compact and place patio stones on top of gravel then place tub I know this is ideal situation but Is this required I am only living in Edmonton for 3yrs so I plan on taking my tub when I leave. Thanks for your input.

[Glid]

Always think about frost heaves in the colder climate. Topsoil=frost, even under the tub. With an LSE, you should maintain a level tub.

I live in New Hampshire, close to the 45th parallel and I eliminated any chance of frost by digging down to clay, 18in and compacting gravel to the tub level. I think it still shifted a little last winter!

[tnt3]

Always think about frost heaves in the colder climate. Topsoil=frost, even under the tub. With an LSE, you should maintain a level tub.

I live in New Hampshire, close to the 45th parallel and I eliminated any chance of frost by digging down to clay, 18in and compacting gravel to the tub level. I think it still shifted a little last winter!

Thanks I will giv eit a try.

[RuBaDuB]

I eliminated any chance of frost by digging down to clay, 18in and compacting gravel to the tub level. I think it still shifted a little last winter!

Frost will travel thru sand, clay, gravel, you name it. There are only two ways to completely avoid frost heave:

1. Put your underside of concrete pad below the local frost level. That's 4'-6' below grade in most areas of Canada, less as you head south. However, it's insane to do a pad this thick for a hot tub.

2. Put your concrete pad on top of 3"-4" of rigid insulation. Extend the edges of insulation out past the edges of the pad by 3'-5', depending on local frost depth, to keep frost from getting under the slab or under the edges of the concrete.

Again, both of these are overkill for a tub...I'm just trying to shed light on the misconceptions of frost heave. If you truly want to avoid any frost heave, for whatever reason, this is the only way to do it.

The real important thing for tubs is that you don't get "differential" settlement/heaving of your foundation...ie. some parts sink, while others move up. This can cause twisting and other stresses on the tub frame. Some tubs can withstand this movement, while others might separate at the joints or even crack. Arctic says their tubs can go right on grass so I assume that means they claim their frame is strong enough to withstand any differential settlements/heaves. I would play it safe anyway though and at least do a solid foundation of wood or concrete that will move as one unit under differential settlement/heave.

[Glid]

Off topic, a little:

I got in my tub last winter when it was negative 15. I sat back and watched the steam rise and all of a sudden, CRACK! The frame vs the shell shifted from the thermal coeficient diffeerence and let out an enormous sound that had me question the integrety of the shell. In the end, no issues.