Cement Slab Or Not?

[Matthew B]

Looking for a good second hand spa off Craigslist and have started my site prep. The electrical is pretty straight forward since I do that fairly often, but not so sure if a cement slab is better than the piece together pads the local spa dealer sells. I planned to put a good stone base of modified under the tub and then put the piece together pad on it.

I'm concerned about a flat pad holding water and preventing it from running away from my house since the tub will be near the house. Plant o have some decking put around the tub.

Any suggestions?

As far as a tub goes, I'm looking for a Master Spa, Caldera or Jacuzzi tub.

[reeffreak]

Looking for a good second hand spa off Craigslist and have started my site prep. The electrical is pretty straight forward since I do that fairly often, but not so sure if a cement slab is better than the piece together pads the local spa dealer sells. I planned to put a good stone base of modified under the tub and then put the piece together pad on it.

I'm concerned about a flat pad holding water and preventing it from running away from my house since the tub will be near the house. Plant o have some decking put around the tub.

Any suggestions?

As far as a tub goes, I'm looking for a Master Spa, Caldera or Jacuzzi tub.

I went with the 2x8x16 solid concrete blocks from the foundation section of Home Depot (think ghetto pavers). 50 of them will make an 80"x80" pad at for $50 + stone/sand base. Cheapest "paver" solution I could come up with. Much less $$ than a spa pad, and drains well.

[spatech (the unreal one)]

Looking for a good second hand spa off Craigslist and have started my site prep. The electrical is pretty straight forward since I do that fairly often, but not so sure if a cement slab is better than the piece together pads the local spa dealer sells. I planned to put a good stone base of modified under the tub and then put the piece together pad on it.

I'm concerned about a flat pad holding water and preventing it from running away from my house since the tub will be near the house. Plant o have some decking put around the tub.

Any suggestions?

As far as a tub goes, I'm looking for a Master Spa, Caldera or Jacuzzi tub.

A cement pad is always a great way to go but the pads, paving stones, and other alternatives can work fine IF the ground is prepared properly.

As far as a tub goes, I like two of the three on your list and normally if this was a new spa I'd have a persoanl short list such as Caldera, D1, Hot Spring, Jacuzzi, Marquis & Sundance but with a used spa I'd broaden that search to include some others that get pretty good reviews here like Arctic, Artesian, Beachcomber, Bullfrog, Clearwater and Dynasty since with used spas you can't sit there and wait for a certain brand or model to show up as available.

With all used spas, condition is everything but its also a MUST that you see the spa filled, up to temp and fully operational.

[Matthew B]

I thinking of going with a stone/sand base over the concrete pad. Too expensive for a 8x8 or a 10x10 pad based on the prices I have seen.

Was told a 6 inch base of 2B stone is all I need. Not sure if the sand is on top of under the stone. Was told a tub pad system would not be needed if the stone is packed well enough below grade.

What have other folks been doing with stone and sand?

[craigjl]

I thinking of going with a stone/sand base over the concrete pad. Too expensive for a 8x8 or a 10x10 pad based on the prices I have seen.

Was told a 6 inch base of 2B stone is all I need. Not sure if the sand is on top of under the stone. Was told a tub pad system would not be needed if the stone is packed well enough below grade.

What have other folks been doing with stone and sand?

I'm not sure what the compaction standards are for 2B but 4" of 411 compacted at two inch rises with a vibratory plate compactor makes a pretty sturdy base. In our area we would typically set something like a paver patio on four inches with pretty good success. So, going with a couple more inches likely will not hurt. If you go that route I doubt that you would need any type of tub pad system. It is important to make sure that you compact evenly and don't try to compact the entire six inches at once.

[Jospher]

I am by no means an expert but I did recently pour a concrete pad for my spa. I would only suggest as I did to check with the manufacturer if the warranty would be voided if not on concrete. That is if the spa comes with a transferable warranty. Good luck.

[Dnepr Dave]

Don't worry about slanting your base away from the house to promote drainage, a spa doesn't have to be dead level. Mine is on a cement patio that slopes. There is a one inch difference in water level from one side of the tub to the other, it hasn't been a problem. I did put the filter suction at the "deep end" though.

Dave

[reeffreak]

I thinking of going with a stone/sand base over the concrete pad. Too expensive for a 8x8 or a 10x10 pad based on the prices I have seen.

Was told a 6 inch base of 2B stone is all I need. Not sure if the sand is on top of under the stone. Was told a tub pad system would not be needed if the stone is packed well enough below grade.

What have other folks been doing with stone and sand?

I think the requirement of a paver/tub pad system on top of crush depends on the tub you end up getting. My tub has 2x2 runners underneath, and I'm sure they would work their way into the base if the tub was set directly on crush. Thus my decision to use 2x8x16 solid cement blocks as "pavers." On a compacted 3-4" base with 1/2" sand on top, and more swept into the joints. It's not going anywhere. If my tub was flat bottom, putting it directly onto compacted crush would have prob been OK. Hope this helps.

[footie]

I think it's always a wiser decision to mount your hot tub on a concrete slab where ever possible, but if that isn't a option then use the heaviest treated wood you can get. I don't think re-enforcing the concrete is necessary unless you question the foundation the slab is mounted on.

[karenb]

I went through the same debate with myself last year when I bought my first spa (Limelight Pulse). I went with a crushed stone pad. No cement or anything else on top. 11 months later, the tub is still as level as it was the day it was delivered!

[north_of_boston]

Looking for a good second hand spa off Craigslist and have started my site prep. The electrical is pretty straight forward since I do that fairly often, but not so sure if a cement slab is better than the piece together pads the local spa dealer sells. I planned to put a good stone base of modified under the tub and then put the piece together pad on it.

I'm concerned about a flat pad holding water and preventing it from running away from my house since the tub will be near the house. Plant o have some decking put around the tub.

Any suggestions?

As far as a tub goes, I'm looking for a Master Spa, Caldera or Jacuzzi tub.

I used the EZ-Spa pad http://www.ezpads.com/ because I had a January (Massachusetts) delivery.

I used sand to level it out -- bags from the big box, and a 2 x 4 x 8 to smooth it out and pre-level it.

6 x 6s around the edge to keep the sand from running out.

I'm not saying it's the best solution but it is a quick one. $319 total s&h. It worked for us.

[DaveR]

+1 on crushed stone but it must be level and compacted. My wife works for a pool/spa service company (yea shes a pool girl) and they see more issues with slabs than they do with crushed stone. Better drainage less rot and maybe just too many incorrectly installed slabs. If the slab starts to tip crack or breakup then it's a pain to repair/replace. They have never seen a spa installed on crushed stone tip and if it did it would be very easy to add additional fill.

Our HS Grandee is set on a base of 4-6" of class 5 (roadbed gravel) which was compacted level, then we added about 3" of pea gravel on top for better drainage on which we set the Grandee. We built 4'x6' sections of Trex decking cut to shape around the spa that we lay on the ground/pea gravel so we aren't stepping on the pea gravel and they are very easy to pick up an move if needed.

Dave

[footie]

I got my concrete slab cut into the garden last week, the job was done by my local gardener come handyman and frankly it is an exceptional job he did. 5 inches of concrete surrounded with a 1 1/2 inch treated wood trim that is part cut into the garden and part cut into the decking. Whole job including the materials came to £190.

Now tell me that isn't good value.

[footie]

Here's a picture of the guy's handiwork.

Can't complain at £190 of work and materials.

[Mike0503]

looks great, I dont know if I want to do pave stone or cement slab.

[Spa_Guru]

Paving stones can shift individually, concrete reinforceds with hardware cloth wire will not,

Any shifting of support is always bad for a spa, do it right!

As for used tubs, never buy a tub that is not full of hot water and be certain if it is more than a couple years old that you can get it out flat, not on its side, older tubs do not travel well tipped.

[worldboy79]

We are doing the hot tub installation in steps, the patio came first. I went the pavers route, more so because of cost and I figured it would be more attractive to use as a patio, made it bigger than the actual tub size.

I just wanted to suggest that if you are planning on buying a hot tub brand new it might be a good idea to check your owners manual or check with the manufacturer.

I was viewing a few manufacturers manuals on line and most have a section on product placement. Most are okay with having the tub placed on a reinforced concrete slab, patio pavers, or a deck (providing it can bear the weight). Some brands even will let you place it on gravel. Some brands, however, specifically state in the manual that the tub must be placed on concrete only, or a deck, and anything else will void the warranty.

[Mike0503]

We are doing the hot tub installation in steps, the patio came first. I went the pavers route, more so because of cost and I figured it would be more attractive to use as a patio, made it bigger than the actual tub size.

I just wanted to suggest that if you are planning on buying a hot tub brand new it might be a good idea to check your owners manual or check with the manufacturer.

I was viewing a few manufacturers manuals on line and most have a section on product placement. Most are okay with having the tub placed on a reinforced concrete slab, patio pavers, or a deck (providing it can bear the weight). Some brands even will let you place it on gravel. Some brands, however, specifically state in the manual that the tub must be placed on concrete only, or a deck, and anything else will void the warranty.

Thanks for the post, I had not really considered this, I will check what mine says prior to the tub getting here.

[footie]

There is one certainty, and that is that cement slabs are 100% approved by all hot tub manufacturers. Personally I think that if it's at all possible I would try and cut out a section of decking and pour in a cement slab for your tub to sit on, of course remembering to leave some form of excess to maintenance for the tub's equipment. The very fact that your decking sits two foot off the ground means that you only need to pour the slab on top of the ground instead of sinking it so it's something that you and a couple of mates could easily do in an afternoon.

I would seriously look at this option if I were you.

[Spa_Guru]

Having done hot tub repair for over 20 years, I can tell you for a certainty pavers are NOT a good long term choice, the center of a hot tub typically weighs more, and puts more weight on the pavers than the edges, so the center sinks, the edges do not, and this causes the edge of the spa shell to bear down on the cabinet, the cabinet or the shell, whichever is stronger, gives way to the two tons of weight.......

[footie]

Well it appears that long term the best option is a properly constructed concrete slab with steel mesh for added support. It might be finanicial pain in the beginning but it will repay you by maintaining the structure of your tub.

[arnspa]

As far as a tub goes, I'm looking for a Master Spa, Caldera or Jacuzzi tub.

So much advice, so little data. How many pounds over what footage are we talking here?

A smaller Master tub with 4 people might be 2 tons, a small Master swimspa with six people might be 7 tons.

In any case reinforced concrete (wire or rods depending on thickness) over a well compacted gravel base is very smart. Some houses are sitting on a shale shelf where water doesn't drain and you can almost put your tub on the grass. But many houses have uneven fill that cannot be trusted.

For smaller jobs, any ambitious yardman can do this, as our UK friend attests. Hey, DIY can do it. For bigger jobs, any concrete job, get someone who knows how to level and finish a pad.

Once you have in mind what size tub you want, I suggest you get bids from people who do this kind of work. They can tell you where to go.

[DK117]

Having done hot tub repair for over 20 years, I can tell you for a certainty pavers are NOT a good long term choice, the center of a hot tub typically weighs more, and puts more weight on the pavers than the edges, so the center sinks, the edges do not, and this causes the edge of the spa shell to bear down on the cabinet, the cabinet or the shell, whichever is stronger, gives way to the two tons of weight.......

thanks for posting this. I wonder though ... opinion statements here guys ... if you installed a proper base and have your pavers ringed in concrete I don't see how it would be much different than a slab. Further, the pictures maybe look like a failure of the cabinet? Remember I'm the guy with a Strong cabinet and a beautiful paver patio. Only one year old so I can't say that it's going to last a lifetime, but I think you're posting one extreme example to make a rule for all. I'm glad you shared it, but I'm not sure you can say that all paver installations are bad for all tubs.

thanks

DK117

[spawn]

In my opinion properly installed pavers on a properly prepared base would adequately support a hot tub, but I am not a hot tub manufacturer, just a civil engineer.

[Mike0503]

Do cement when you lay all the sand and then pavers and sand over the pavers and tie them in, taking in account labor and your time you can have a nice strong slab of cement that will not move. I was researching the same thing and in time the pavers will move, and the sand with shift with water and so forth. Setting the forms for the slab.

http://i944.photobucket.com/albums/ad289/steeldavidson/IMG_1196.jpg