Paver Base for Cold Area?

[jason26]

So we are going ahead and putting in a swim spa.  There is currently a paver base that the previous own had a hottub on, but upon closer inspection is not level at all, so it looks like I have a big job ahead of me.

Given we have temperature extremes of -30C to +40C, is a paver base even recommended?  Moisture is not really an issue.  This the high part of the yard close to the house, and there seems to be good drainage out and away from the house.

My other though was removing all the pavers out, removing the sand that is under them (I don't think there is any gravel under that, which could be why they are no longer level?) and filling with crushed gravel.  Then putting the hottab right on the crushed gravel, and then placing something more decorative on top of the gravel around the tub right on top of the gravel, perhaps decking?  It would come up around 2-3 inches from the ground, but I'd probably do it in panels so they could be remove easily if the bottom edge of the tub needs to be accessed.

Of course there is the concrete pad option, but we're least keen on that.  We think we could make anything else look better, and I think concrete has its own issues in our temperatures, at least going to our side walks, driveways and other cement walkways!

Thanks!

[Sam]

Swim spa's are a lot heavier than regular hot tubs.  I would see what the manufacturer recommendation for a foundation is.  Insufficient foundation can cause major problems including cracking of the shell.  This potential is magnified with a swim spa.  There is almost always a clause in the warranty stating that an improper foundation can void it.

[Tman122]

Yea your going to have to see what the manufacturer suggests but what's under the final surface choice is the most important part of the process. The deeper you can go with sand/gravel/class 2 limestone the better in extreme climates. I'm in Northern Minnesota so understand the climate. I have seen just about every type of foundation and the prep work seemed to be the most important factor in any failures or successes. Sounds like you have the drainage part good. Not all swim spas here stay full and heated for the winter. Almost always an indoor thing here.

[jason26]

So other than a cement pad, crushed gravel was recommended.  I went to my local garden and landscaping place, and they have "base gravel" which is smaller rocks mixed with dirt, looks like it would compact really well.  They also had "crushed gravel" which really was just rocks - no dirt or anything very fine in the mix.

Is "crushed gravel" really what I'd be after?  They suggested at least 6" of the stuff.  I'm assuming a little more wouldn't hurt?

Thanks

[Topline Mike]

Six inches will be fine.  As long as you have a solid base, I would think 4 inches would work.  I would rent a plate compactor from your local hardware store.  Maybe set some treated 2X4's along the edge to separate the gravel from your yard.  Create a rectangle with them, making sure they are level.  Use another 2X4 to "screed" the gravel smooth, then compact.  Add more gravel, screed, and compact again.  You'll have a nice base in no time. 

[jason26]

Cool.  Sounds good.  Basically its like I'm building yet another sandbox, just with a different contents..  Yes, a border of treated 2x4 or 2x6s was in my mental plan to lock the gravel in place.

Alright, thanks for the tips guys..  I'm pretty confident I know what I'm doing now.

[Tman122]

Class 2 limestone layered and compacted is what we use under our roads. Wet it and use a plate compactor as you go a couple inches at a time and it will be like concrete when your done.

[Water Boy]

So we are going ahead and putting in a swim spa.  There is currently a paver base that the previous own had a hottub on, but upon closer inspection is not level at all, so it looks like I have a big job ahead of me.

Given we have temperature extremes of -30C to +40C, is a paver base even recommended?  Moisture is not really an issue.  This the high part of the yard close to the house, and there seems to be good drainage out and away from the house.

My other though was removing all the pavers out, removing the sand that is under them (I don't think there is any gravel under that, which could be why they are no longer level?) and filling with crushed gravel.  Then putting the hottab right on the crushed gravel, and then placing something more decorative on top of the gravel around the tub right on top of the gravel, perhaps decking?  It would come up around 2-3 inches from the ground, but I'd probably do it in panels so they could be remove easily if the bottom edge of the tub needs to be accessed.

Of course there is the concrete pad option, but we're least keen on that.  We think we could make anything else look better, and I think concrete has its own issues in our temperatures, at least going to our side walks, driveways and other cement walkways!

Thanks!

It sounds like maybe you pulled the trigger on one! If so, congrats! What model did you end up going with?

[jason26]

So we are going ahead and putting in a swim spa.  There is currently a paver base that the previous own had a hottub on, but upon closer inspection is not level at all, so it looks like I have a big job ahead of me.

Given we have temperature extremes of -30C to +40C, is a paver base even recommended?  Moisture is not really an issue.  This the high part of the yard close to the house, and there seems to be good drainage out and away from the house.

My other though was removing all the pavers out, removing the sand that is under them (I don't think there is any gravel under that, which could be why they are no longer level?) and filling with crushed gravel.  Then putting the hottab right on the crushed gravel, and then placing something more decorative on top of the gravel around the tub right on top of the gravel, perhaps decking?  It would come up around 2-3 inches from the ground, but I'd probably do it in panels so they could be remove easily if the bottom edge of the tub needs to be accessed.

Of course there is the concrete pad option, but we're least keen on that.  We think we could make anything else look better, and I think concrete has its own issues in our temperatures, at least going to our side walks, driveways and other cement walkways!

Thanks!

It sounds like maybe you pulled the trigger on one! If so, congrats! What model did you end up going with?

We went with the Coast.  In the end it came down to cost.  The Arctic did seem like the Cadillac, and the Coast felt a little lesser, but the large cost difference sold us.  The only thing that anyone could really tell us that was better on the Arctic was the forever bottom.  And Coasts PVC bottom is definetely a lesser bottom, but I think its good enough for the foundation we gave it.

In more general to this thread, we had a bobcat come in and scrape out dirt down to clay (12-16"), and then filled that in with crushed rock.  I'm pretty confident its going to stay solid for years to come, and so was everyone I showed it.

But the wife has landscaping plans which may change the orientation of the tub sigh.. .In which case I'll just write the check and have a cement thrown down so she can't change her mind again!