Jump to content

Hot Tub PAD


Recommended Posts

Hi Guys,

I been browsing this forum and I seen a lot of smart people...

I purchased Sunrisespa ... 7 person 90x90

I don't want to pure concrete, is gravel bed an option ?

My only concern is that I have little slope currently ( its kinda like a little ditch where water runs down to the drain ) its couple inches off nothing major .. 

Remove 6 inches of soil, use ground contact rated 4x4 ... use gravel with gas compactor compact as much as possible.

Warranty says to no put on gravel but I will talk with them... they say to use tiles, pavers .


I'm in Ontario so frost is a thing :)


Any tips ?


Thank you

Link to comment
Share on other sites

1 hour ago, Ndx said:

Remove 6 inches of soil, use ground contact rated 4x4 ... use gravel with gas compactor compact as much as possible.

Warranty says to no put on gravel but I will talk with them... they say to use tiles, pavers .

Lay down a inch or 2 of 3/4 crush gravel.  Build a 4 x 4 picture/window frame with a few extra supports within it and back fill with screening. Make it the same size as the base of the spa so that when on the pad the skirting will over hang it a bit and allow water to go to ground and not onto the wood and back under the spa but really not a big deal. The spa will be on wood and not gravel. As for the warranty in relation to the base never seen it happen.

Where in Ontario? We might have done your delivery... Hot Tub Movers

Send me a PM if you have Questions and include your number. I am out of Milton

  • Like 1
  • Thanks 1
Link to comment
Share on other sites



Just so I understand


Remove 6 inches

Put 2 inches of 3/4 gravel > compact ?

Then place the 90x90 4x4 frame with some cross support in the middle ?

And then fill the rest with gravel and compact over frame ?


Or digg 6 inches compact compact and then 4 inches frame and fill and compact ?

Sorry don't want to end up with cracked tub haha 😅


Sorry what is screening ? 

And I want 3/4 crush run gravel ?

Something like this filled with gravel ? Laying on gravel ?



Or just true frame pictur filled like this 



And yes you will be doing delivery soon !! :)

Link to comment
Share on other sites

Yes place the frame in the photo on top of a couple of inches of 3/4 gravel for drainage and place the frame in so it's nice and level. Then just back fill the openings with limestone screening (fine gravel) so that is flush/level) with the inside edge of the wood frame. You want the spa to sit on the wood frame. The limestone is there for stability and extra support. Make the top edge of the wood frame about 2" above grade so it sits up a bit off the grass. Mine is going on 10 years and still sits level and I have had dozens of spas on it. 

  • Like 2
Link to comment
Share on other sites



Thank you !



I will start building frame and prep site, I think I will go more extreme and take out like 5 inches compact crush, put frame on this and then I will put the screening as you suggested 

It's mainly because I already have run crush stone from another project 

Hope that's ok ?

Where do you buy wood that's ground contact approved ?

And I will msg you for number if ever need service...

Link to comment
Share on other sites

  • 10 months later...


Good information.   Have a few questions myself

So I have a Master Spa 8.25 It's been sitting on my Deck which is concrete with a Gazebo.

What I would like to do is regain that part of my deck back and install the tub to the side of the deck.

Are 4x4 P.T. ok for this? I always thought you would need 6x6 just for the weight?

Or is it because they suggest going down 6" into the earth to get a much more solid base and top up 4" of 3/4 crush and 2" pea stone.

But if I go that deep isn't the 4x4 laying under all this? Or would you suggest laying 2" of stone then lay the form on top and then top off with the remaining stone and pea gravel

Tub and Gazebo is 9' 6" x 9' x 6"  Was originally planning on a 10' x 12' just the extra with to be able to close and open the lid while still staying on the gravel. But thinking more along 10 x 10 better esthetics if we ever decide to get rid of the Gazebo. 

At the cost of lumber here in Ontario the difference between 4x4 and 6x6 is close to $30 a piece now.

For our American friends yes the wood prices here have become insane 4" x 4" x10' $25  6'x6' x 10' are close to $60

Picture of tub position now and where we would like to place it :)





Link to comment
Share on other sites

My own pad I just went down a few inches and laid down some 3/4 crush gravel for drainage and then laid some limestone screenings to level it out then place the 4x4 wood frame work onto the level screening base and backfilled the open areas level with the top of the 4x4's with the limestone to lock it in place. When finished I had 2" of 4x4 above grade to keep the spa up off the ground. You will see in the pics attached it's barely even in the ground and if I cared about the look I would sink it down so only about a 3/4" above grade. You will also see the limestone is a little low in the middle and will have to add a bit but keep in mind over the past 10 years I have have over 100 spas of all different sizes on it so when a smaller spa is on it the rain gets at it and washes it out a bit over time. It was 100% level when installed all those years ago and at present it is maybe 1/2"  low on the one corner and could easily level it but the minor tilt helps me doing leak detection. If a spa gets a leak I know where to look to see if it is leaking during testing. Good Idea to make sure you have good support where the foot well will sit as it carries the most weight.

P1040545.thumb.JPG.0b08ef0bbb1e97e6554bb23b93c50d35.JPGP1040547.thumb.JPG.5944d3cb00b5b6d4d7bf625559039b72.JPGA wise man once said "flat is better than level".

For the size of the wood base.. if you look in the photo the side skirting of the spa is wider than the base of the spa. I would make the wood frame to the exact size of the base so when it rains the water will run down the side skirt directly to the ground on the outside of the wooden base and not on to the wood frame and/or back under the spa.

Whatever you end up doing start a new post and detail your adventure and help the next guy 👍



  • Like 1
Link to comment
Share on other sites

With the Gazebo I don't have much worry in regards to the water running under the base. But of course that may change if we decide to remove the Gazebo entirely.

Making the actual gravel pad a little over a foot on either side of the tub. So hopefully whatever water is draining our getting to it will drain into the gravel along side of the tub. Can't imagine to much run off from there but hey who knows :)

The only dilemma I can see at the moment is the concrete patio is roughly 6" thick and with the slope away from the deck area I am about 4" below the deck at the back of the tub where the placement will be.

Even if I can get at least 2' into the ground and tamp it down to compact it with the 2" of 3/4 crush I should be able to manage the remaining frame onto that and retain the remaining grave and pea stone to stay still.

In theory it should work but I guess we will find out.

Hoping to keep the nose of the tub on the concrete. Any thoughts on that support? And allow the remaining part of the tub to sit on the gravel inside the frame, basically sitting on the gravel.

If you would suggest keeping the tub completely on the gravel and not being supported by part of the concrete deck, let me know your thoughts.

Can always lower the tub from the face of the deck and just make sure it's back enough to allow the front panel to be removed.

Tub is 94" x 94"   Actual gravel pad will be 120" x 120"  So significantly wider.



Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...