Putting a Prefab Spa In Ground

[PoolPaul]

As part of our house build we're getting a fiberglass prefab spa installed and the plan is to put it in the ground (concrete block vault filled with concrete) so as not to stand out when looking out the French doors.

I have plans from the landscape architect, but looking for advice from people who have done this--mistakes, things that you really liked about how you did it, things you wish you did differently, etc. We will be able to drain water to our yard drainage, so that shouldn't be a problem.

Advice?

 

[ajw22]

Will your spa spillover to the pool or will the spa be standalone with its own pump and filter?

 

[jseyfert3]

If standalone, you'll at a minimum want someway to access the equipment bay without lifting the entire spa. Speaking as someone who had a leak in there and just had a siezed pump motor.

 

[PoolPaul]

@ajw22 --it will be a freestanding spa with its own pump and filter in an area separate from the pool. Probably one of the Bullfrog models.

@jseyfert3 thanks--the landscape architect designed an area for equipment access on one side. Not all the way around though.

 

[jseyfert3]

@jseyfert3 thanks--the landscape architect designed an area for equipment access on one side. Not all the way around though.

I also have a leak somewhere else in the spa, which is not accessible from the equipment bay, but I haven't tracked it down yet. Could be on a different side or under the tub entirely. But we inherited this 2008 tub this spring when we bought the house, and inherited the (very slow) leak. So I don't know if it was improper care such as freeze damage or just bad luck. I'm going to be trying to locate that shortly.

 

[ajw22]

I do not jnow the construction of the Bullfrog spa. I had a Sundance spa a while ago and its PVC plumbing was all glued. As it aged the glue joints began leaking and various sides of the spa needed to be opened to find and fix the leaks. A spa where the plumbing is screwed together rather than glued is preferable. And have some plan if you need to get into other areas of the spa then the equipment bay.

 

[RDspaguy]

Pvc gets glued, the manifolds and jetbacks on a new tub are likely barb fittings with clear hose and hose clamps. But those can leak eventually too.
At some point, it's going to have to come out of the pit. I would advise that you install it on blocks in the pit, being sure it is well supported at center and edges, to allow access for straps and keep it off the ground, which will be frequently wet in that pit, and will greatly increase the rate of deterioration of equipment, cabinet, and frame.

 

[PoolPaul]

@jseyfert3 and @ajw22 the one good thing about the Bull frog is there's only a single tube going to each seat, and the "jetpacks" are fed by that one tube. Greatly reduces the amount of tubing.

@RDspaguy interesting thought. Sounds like I could use something like a large pallet made from something that doesn't deteriorate. Any suggestions? I guess I could use a bunch of blocks but not sure how well that would work with the fiberglass of the tub.

 

[RDspaguy]

The bottom must be supported across the footwell, which is where most of the weight falls and at the corners and center of each side. You could use a dozen 12x12 flat pavers, only raising it 2", to allow space to get straps under it. I have pulled many spas out of pits and decks, and getting the straps under it is the hardest part.
Also, be sure to leave a little room on the sides as well, or straps won't work and you will have to try to air bag it out, which is just ALMOST impossible without a little wiggle room. Cover the gap with a removeable wood frame or some stone block or whatever, but leave some room. The only tubs I ever had to give up on had no wiggle room.
And don't think for a moment that bullfrogs design means it's less likely to leak. It may have fewer things to leak, but they use the same materials (pvc, glue, gaskets, etc...) as everyone else.

 

[PoolPaul]

The bottom must be supported across the footwell, which is where most of the weight falls and at the corners and center of each side. You could use a dozen 12x12 flat pavers, only raising it 2", to allow space to get straps under it. I have pulled many spas out of pits and decks, and getting the straps under it is the hardest part.
Also, be sure to leave a little room on the sides as well, or straps won't work and you will have to try to air bag it out, which is just ALMOST impossible without a little wiggle room. Cover the gap with a removeable wood frame or some stone block or whatever, but leave some room. The only tubs I ever had to give up on had no wiggle room.
And don't think for a moment that bullfrogs design means it's less likely to leak. It may have fewer things to leak, but they use the same materials (pvc, glue, gaskets, etc...) as everyone else.

Thanks. I'll make sure we leave space for straps.

On your last point, just seems mathematically a tub with fewer pipes and joints would be less likely to leak than a tub with more joints, assuming the failure rate based on the X failures per Y joints is the same for all tubs, but maybe I'm missing something.

 

[RDspaguy]

If your glue joints or gaskets fail, they all fail. They are all in the same water, with the same batch of gaskets, pipe and glue. Freeze it, it breaks. Fewer parts to replace perhaps, but not less likely to leak.
On most tubs pvc leaks and gasket deterioration are pretty rare without some cause, such as poor chemistry or freeze damage, or just plain old age. Though there have been a few notable exceptions over the years, where a certain brand and year are known for certain issues across the board.