What is the best way to level a patio?

[passmaster16]

I'm looking at the Hot Spot Tempo right now.  I would like to put it on my patio.  The previous homeowner built the patio out of brick which are motared together (see attached photo)  There is a concrete base under the brick so it's solid.  The biggest concern I have is with high and low spots in the patio causing the tub to not be fully supported.  Since you're not supposed to shim the tub, what are my best options for creating a level surface on top of the patio.  A couple things that I've seen suggested in my research:

1. Use a floor leveling product to even out the peaks and valleys
2. Build a frame using pressure treated 2x4s and fill it with pea gravel
3. Put a 3 inch layer of screeded sand under the tub

Are any of these options viable?  I prefer 2 and 3 because they are not permanent.  Are there any other options out there that might work for my application?

Thanks in advance!

[Dr. Spa™ Ret.]

#2

[Spatech_tuo]

#2

I also would go with #2 and have seen it done that ways many times. The frame needs to be just a bit bigger than the pedestal of the spa and its largely unseen anyway. If the patio is noticeably unlevel you can rip the wood so that the frame ends up totally level on top. This way when you add pea gravel and place the spa there you can have a level spa/water line even if its sitting on a sloped porch/pad.

[Jet Sitter]

#2 with angular aggregate rather than pea gravel...

[Basz]

#2
Or An EZ Pad. EZPads.com

[passmaster16]

OK, I took the advice of everybody here and built out an 8 x 8 box frame using 2 x 6 pressure treated wood.  I decided on using 2 x 6s vs 2 x 4s to give me a little more wiggle room for a more solid base.  I plan to fill the box with 3-4" of 2a limestone aggregate which is a mixture of fine stone up to 1.5 inches.  I've used this stuff for patio base and it packs down almost as tight as concrete.

The concern I had is once I built out the box frame, I noticed that it is not touching the ground on all sides.  This is due to the fact that the patio is motared brick and has high and low spots.  I wasn't sure if I should be worried about the gravel washing out of the box because of this.  The gaps are not very large but they do exist.  Should I be concerned or will the gravel stay put once it's packed down inside the box?  I was thinking about putting down some type of plastic or landscape fabric and stapling it to the inside of the box to hold the gravel in place.  I'm not sure if it's worth going to this trouble or not. 

The only other question I had was do you think it's necessary to secure the box frame to the patio?  My thought was the the box was heavy enough that it really shouldn't move once in place, but I wasn't sure how much pressure would be exerted on the box once the gravel and tub are sitting in side.

[raysdad]

how wide are the gaps in inches?.. unfortunately "not very large" isn't much help.  If very narrow run a line of silicone caulking, if they are wider - aerosol expansion foam insulation should do the trick.  If the top of the form is not level, you might want to rip the sides accordingly and take care of your gaps that way.  It all depends on how clean you want your install to look when your done. 

[passmaster16]

how wide are the gaps in inches?.. unfortunately "not very large" isn't much help.  If very narrow run a line of silicone caulking, if they are wider - aerosol expansion foam insulation should do the trick.  If the top of the form is not level, you might want to rip the sides accordingly and take care of your gaps that way.  It all depends on how clean you want your install to look when your done. 

Largest gap is probably about 1/2 inch or so.  I'm not sure that ripping would be feasible because the issue is that there are a few high and low spots.  The gradual slope for drainge is also there but not as big of an issue as some of the bricks not being the same height.  I don't think caulking would do me much good.  Expansion foam is an interesting thought.  I'm open to other ideas as well.