Gravel Or Crushed Stone?

[cnw]

After reading many threads in this forum I am still confused. I built a 9' X 9" box out of PT 2 X 10s and will be filling it up with stone for my new Caldera Martinique to rest on.

I have heard that pea gravel is best although it doesn't pack down well

Others prefer crushed stone but the dealer says to avoid it becuase of the jagged edges.

Maybe the larger round, 1" or 2", stone is best?

Any thoughts? Thanks.

[Brian_GP1200R]

Why not just pour a 4 inch concrete slab?

[dave nh]

if you are going to go that route i would add a top layer of masons sand or stone dust for the part that is going to be directly under the tub at least a couple of inches.

[cnw]

Thanks, I like that idea.

[cnw]

Can't fit the truck in my backyard

[Brian_GP1200R]

I couldn't get a truck either, so instead mixed up the concrete bags in a little electric mixer from Home Depot. It cost about $40 for the day and would mix 2 bags at a time. Each load took about 2 minutes to mix up. Surprisingly it only took about 2 hours to mix up and pour 31 bags for my slab... and it's STURDY :-) It really wasn't bad at all until it started raining during the finishing process :-/

[Roger]

After reading many threads in this forum I am still confused. I built a 9' X 9" box out of PT 2 X 10s and will be filling it up with stone for my new Caldera Martinique to rest on.

I have heard that pea gravel is best although it doesn't pack down well

Others prefer crushed stone but the dealer says to avoid it becuase of the jagged edges.

Maybe the larger round, 1" or 2", stone is best?

Any thoughts? Thanks.

Neither is good I would get myself 3-4 wheel barrows and 3-4 guys to wheel it while your trowel it or broom it. Couple hundred for concrete or stone and concrete is far superior.

[ps558]

After reading many threads in this forum I am still confused. I built a 9' X 9" box out of PT 2 X 10s and will be filling it up with stone for my new Caldera Martinique to rest on.

I have heard that pea gravel is best although it doesn't pack down well

Others prefer crushed stone but the dealer says to avoid it becuase of the jagged edges.

Maybe the larger round, 1" or 2", stone is best?

Any thoughts? Thanks.

If you can't the slab route why not a wooden deck? Many spa manufactures will void the warranty if the spa is sat on stone gravel, etc. That is about 4000 pounds with all the water and if it sinks in are stresses the shell or cabinet it could void the warranty.

Also what about spas pads companies make

[spatech (the unreal one)]

After reading many threads in this forum I am still confused. I built a 9' X 9" box out of PT 2 X 10s and will be filling it up with stone for my new Caldera Martinique to rest on.

I have heard that pea gravel is best although it doesn't pack down well

Others prefer crushed stone but the dealer says to avoid it becuase of the jagged edges.

Maybe the larger round, 1" or 2", stone is best?

Any thoughts? Thanks.

Everyone will say concrete is best and that is true but not everyone wants to do that for varying reasons. So assuming you're not going to put concrete, I've seen pea gravel in a frame as you described work just fine. I think crushed stone will work fine also and while there may be some jagged edges I'm not sure how that will lead to a problem; its not as if the plumbing will be contacted and who cares if it mars the bottom of the spa. The rounder rock will work as well but don't get too large so you now it will settle well and distribute the weight evenly.

[Brian_GP1200R]

I think the point is that he might be able to still do concrete, save money, and not worry about the gravel... if he chooses to do so. Otherwise I would think that the most round gravel would be best, but I would still be concerned that it could void warranties, etc... I would def check what the manufacture recommended prior to instalation.

[spatech (the unreal one)]

I think the point is that he might be able to still do concrete, save money, and not worry about the gravel... if he chooses to do so. Otherwise I would think that the most round gravel would be best, but I would still be concerned that it could void warranties, etc... I would def check what the manufacture recommended prior to instalation.

"I built a 9' X 9" box out of PT 2 X 10s and will be filling it up with stone for my new Caldera Martinique to rest on."

I think the point is he already has the frame built and is ready to fill it as noted in his first sentence. He won't be saving any $$ by pulling that out and pouring concrete where all he has to do now is add the pea gravel. I'm all for concrete but this owner already has traveled part down a different path which I’ve seen numerous times from people who want an alternative to concrete and I think it works fine.

You do make one good point; check with the manufacturer. See if the dealer has pre delivery instructions and/or call Watkins and talk to Customer Service.

[Brian_GP1200R]

I was thinking that the box sure sounds like a nice (but expensive) frame for concrete if he were to decide he would prefer to go that route.

[ChicagoMike]

You can rent a vibratory plate compactor. I is like a lawnmower size and it vibrates to compact the gravel. It will be very hard when your done. And then how about one of those hard plastic under spa mats as a barrier between the spa and gravel?

[spatech (the unreal one)]

I was thinking that the box sure sounds like a nice (but expensive) frame for concrete if he were to decide he would prefer to go that route.

Most of the time when I see this the frame is only partially buried into the ground at best so I'm no sure it'll double as concrete forms.

I've seen this type frame/gravel used two ways. People who don't want a concrete pad and just partially bury a 2x6 or 2x8 frame in the ground to be filled with gravel. Also people who already have a concrete pad but it has too much slope for a spa so they build a frame but rip it so it sits level on the sloping concrete allowing for them for fill with gravel and have a spa thats level.

[cnw]

Thank you all for alot of great ideas.

The 2 X 10s I used were from an old deck so I wouldn't be sacrificing much if I did fill it up with concrete.

[Greg D.]

Thank you all for alot of great ideas.

The 2 X 10s I used were from an old deck so I wouldn't be sacrificing much if I did fill it up with concrete.

CNW,

You could also use a type of gravel mix called 3/4" crusher run, or in some places it's called quarry process. It's got gravel and stone dust mixed together, and if you dampen it, and run a compactor over it will make a nice firm base for the tub. You'll just have to fool around with several additions of the material or scrapings to remove some in places between compactions to get it nice and level. It's not very pretty to look at though, but if you want to remove the tub it could be dug up with hand tools.

Greg.

[cnw]

Thanks Greg, just used crusher run for the first 3 inches and have 3 more inches to go. I may just stay with that or go with stone dust which would be smoother.

[mlanoe]

I am currently building a base for my new hot tub and using the gravel idea. It was recommended that I used limestone screening. Really fine rock. I build a frame with PT 4x4. I have filled the first half on the base already. Seems pretty sturdy. I water it and tamper it every inch or so. The plan is to finish the last two inches by laying down approximately 15 patio stones ((2'x2'x2") concrete pads) to insure a smooth and level surface and help spread the load properly.

Will try to take pictures and post when I get a chance.