Replacing old tub - need advice with concrete slab which is a little small

[Noxturn]

Planning on buying a new tub to replace old one.

Here is my delimina the - the old tub sits on a 74”x74” concrete slab with the deck build around it.  The new hot tub I’ve picked is 80”x80”

I would prefer to avoid redoing the concrete slab.  Will the new hot work on the old slab with a few inches of overhang on each side?

[bachman]

I wouldn't try it that way. Just shouldn't leave anything to chance IMO if it were me.
First of all make sure the footprint measurements are correct. I thought of my 'pad' size and the tub location as per my electrical conduit coming up and was off the mark by more than half a foot from the proposed corner of tub location.
What happened was I sorta estimated the size of the tub earlier on by use of top measurements my wife made with the cover on and was probably being generous as per other sizing considerations for the terrace / patio never thinking about true numbers at the base.

If indeed the tub base / footprint is bigger than the pad, I'd put in some fill dirt borders, pack it down and top it off and level with 2 to 3" of sand then put down pavers or patio stone as a border all around the concrete pad. This fix should be fast, easy and inexpensive- What more could you want ?  lol
A- It will look pleasant if not 'fancy' and
B- My entire patio and terrace is a raised area with retainer wall block a few feet up from the lawn and it supports the tub just fine (IOW, I know it works) with the steps I outlined. In my case, it was tons of dirt, a ton of sand and a few tons of wall block and pavers.

If you need to build up the border of dirt, sand and pavers, you probably need to create a supporting surround like brick, wall block or 4x4's. 

http://www.gardendecors.net/marvellous-paver-backyard-ideas/fabulous-paver-backyard-ideas-paving-ideas-for-backyards-patio-pavers-backyard-pavers-amp/

https://www.google.com/search?q=border+concrete+patio+with+pavers&tbm=isch&tbs=rimg:CWV9X9w4PCocIjiDo8A4pOTVrHCNlK49_1AaHheyMLM0mt1TO4FemF0KYU6ya1XAMyJLfr7B6krdM3HGpwQpzS04TgCoSCYOjwDik5NWsETx74MhSMYsEKhIJcI2Urj38BocRjf9xWPv8g70qEgmF7IwszSa3VBGY_1mzCLIJgIioSCc7gV6YXQphTEaFdzMbrFaYZKhIJrJrVcAzIkt8RKyTglybBC9IqEgmvsHqSt0zccRHatEyWW0E9TSoSCanBCnNLThOAEQ8IPImEPlXk&tbo=u&sa=X&ved=2ahUKEwj5g5nD-8bfAhVi4IMKHZMTDOUQ9C96BAgBEBs&biw=1486&bih=802&dpr=1.25#imgrc=ZX1f3Dg8KhwpgM:&spf=1546154234703

[swilly1000]

From what you said....I don't like your chances.

Good luck!

[Noxturn]

Thanks for the advice Bachman.  Not sure paverstones are viable.  My backyard is extremely sloped.  The concrete slab that is there is probably 2 1/2 ft tall.  I would probably need to tear out the deck and bring in several ton of dirt to make that work.

My new idea is a 8x8 wood frame that sits on the concrete slab.  I will use 4x4 posts as legs to support where the wood frame would over hang.  That should work and easily hold the weight of the tubs?  Any flaws with.  I see a lot of people who set their tub on a wood deck and I’ll make sure my frame is significantly stronger

[bud16415]

That only leaves 3” per side my tub has a toe kick at the base that’s at least an inch and the tub lip at the top another inch. You may be talking only an inch on a side overhang in the end.

I like my tub sitting on our wood deck as the spaces allow water and air to get under the tub.

Is the new tub the same height and is the top height even an issue.

I would check with the dealer and find out the exact dimension of the actual foot print and if they don’t know or don’t have one in stock to measure have them contact the maker. I personally wouldn’t worry if it hung over an inch or so and if you want to lay a pressure treated riser 1” below it that could be sized out a tad bigger. I wouldn’t worry about posts for that small amount. But I would attach it to the pad you have so the movers don’t have it sliding when they set the tub.

[Hottubguy]

Planning on buying a new tub to replace old one.

Here is my delimina the - the old tub sits on a 74”x74” concrete slab with the deck build around it.  The new hot tub I’ve picked is 80”x80”

I would prefer to avoid redoing the concrete slab.  Will the new hot work on the old slab with a few inches of overhang on each side?

The 80x80 is most likely the overall dime spins of the tub???  What are the dimensions of the base the tub sits on?  I have a 90x90 tub but the base is 86x86.

[bachman]

Picturing that situation makes me think of a high perch tub and slab with steep slope on one or more sides. I guess the over-size deck on the slab sounds like it might be best but I caution anyone on exact dimensions up front. Do Nothing until you confirm the base size. Even if the exact tub isn't local or "on the floor" at a dealer, the ref size info on another model of same brand as 80 x 80 should be a twin and offer the base details you need to confirm. Best of luck and keep us posted on the project and outcome !