Pad vs. Slab

[wannabeswede]

I live in Northern CA near SF.  We don't have freezes and our soil is very firm in our backyard.  Instead of pouring a slab is a Pad a viable option for me instead?

Any downsides to the Pad?

Tack (Swedish for Thanks),
Kevin

[IBinit4fun]

I also considered using a pad. But it seemed to me that your yard would have to be pretty level and mine was not. The pad is only a couple of inches thick. So if you have to dig more than 2" to level out your spot, some portion of the pad would be below ground level and subject to dirt washing down on top, unless you built a small retaining wall. The alternative would to be to build up the low side, but I would not be comfortable setting the weight of a hot tub on newly packed soil. If you do go that route, you may want to consider some kind of gravel or sand base under the pad. Also check the warranty. My Marquis dealer said it was OK. My HS dealer so no way. I ended up pouring a concrete slab for my Marquis. With sweat equity and a friend to do the finish work, it was about $250 (cost of 2 yards of concrete delivered and gravel). Good luck.

[UnderTheStars]

Hi Wannabeswede and welcome!  Just my opinion, but a slab is probably best because it's flat, stays that way, and is long lasting.  Next up I'd rank a heavily reinforced deck - it's flat, will stay that way, but eventually succumbs to rot (long before the slab is done.)

You can also look at various compacted stone/gravel with some form of pavers on top.  But (again, just my opinion) to do it right you have to do just as much prep as if you were pouring a slab.  The prep is similar to slab, just instead of pouring 'crete you fill with gravel & compact it as you go.  If done correctly, some of these can look really outstanding.

I know nothing about the pads (some here have used them and will hopefully share their thoughts.)  Seems to me if you are planning to use the pad very long you'd have to prep the site - level it, tamp some sand, gravel, etc?   If I were only planning to be in a home for a year, then move - I might consider a pad as an interim solution.  Whatever route you go, you need to ensure there won't be uneven settling over time.  A filled tub weighs more than the car I drive every day.  If part of the ground sinks, your new tub will flex and something's bound to break.

Final thought - check the tub manuf. web site.  For example, HotSpring says the minimum for their biggest tubs is 4" concrete.  For their midsized tubs they acknowlege other options but "recommend" the slab.

Hey, when your shopping/about to buy it's hard to wait and tempting to take a quick route.  (Everyone here has struggled with that one!)  But take the time to consider your options.  .  .then INVEST the time in what will give you the look,  the durability, and the service you ultimately want. . .that adds up to value.

So, what tubs are you looking at?

[ebirrane]

When I had my 2003 grandee installed we looked at the pads but were told, in no uncertain terms, that the pad was not a viable option for a tub of that size.  This was from a dealer that also sold the pads.

So we did a slab, but to save $$ we did it ourselves, make it 6" with 8" footers, 2" gravel base, vapor barrier, and 1/2" rebar every foot. But we were in an odd place with a big angle.

Alot of work, but we did wind up saving about $700.  Of course we got teased alot for the backbreaking work, leading to this edited picture of my wife spreading down the gravel.




-Ed

[UnderTheStars]

Way to go Eberrane!  You're my kind of engineer.  I poured a 6" w/1/2 steel rod as well.  Put mine on 12" of compacted pea gravel.  All told we dug down 18". . .and yep, got teased a lot!  ("whadda ya wanna do all that for?")  Substitute my 18 yr. old son for your wife in the picture and there ya go!

I'll bet this was the same as well:  Slanderous remarks & murderous looks disappeared the instant the jets fired up!

[Spatech_tuo]

Of course we got teased alot for the backbreaking work, leading to this edited picture of my wife spreading down the gravel.




-Ed

That picture has been cropped!! In the orginal picture you see that Ed sitting on a deck chair with a beer in his hand while his wife is slaving away with the shovel.

[ttodd1]

As for the slab, how long should the concrete sit before the tub can go on it? :-/

[UnderTheStars]

3 days minimum.  Concrete hits 50% of its strength in 3 days.  75 - 80% in 7 days.  The rate of cure slows significantly after that.  Keep it wet with plastic over it.  Concrete cures by a chemical interaction w/water, not by drying.  If the surface dries during the first few days, the top of the slab will be weaker and prone to spalling (chips break off the surface from freeze/thaw cycle & weathering.)

[cparlf]

Underthestars posted a very useful and informative lesson regarding concrete on July 14th.  I suggest reading it because it helped me a lot.  It was under my post for "site prep".  Yes, I wusswed out with doing the slab myself and overpaid for the 11.6 x 11.6 5" slab, but 60 plus hour work weeks don't leave a lot of time for major projects.  Have fun, the end results will be worth it.  

[ttodd1]

Thanks.  I thought I saw that post before but just couldn't find it..  (more coffee)

[ebirrane]

Way to go Eberrane!  You're my kind of engineer.  I poured a 6" w/1/2 steel rod as well.  Put mine on 12" of compacted pea gravel.  All told we dug down 18". . .and yep, got teased a lot!  ("whadda ya wanna do all that for?")  Substitute my 18 yr. old son for your wife in the picture and there ya go!

I'll bet this was the same as well:  Slanderous remarks & murderous looks disappeared the instant the jets fired up!

Absolutely.  All of the pain (physical, emotional, spiritual) melted away in the new tub.  Of course, this month we are building the deck around the back of the house, so I guess I should ask my wife to pause painting the house, putting on the new roof, and mowing the lawn long enough to go cut those 4x4's.  

Of course what is not shown is me and the mattick (sp?) digging those trenches.  I would love to have been here when the were making the refuse pile our house apparently sits on.  While digging I found:

1) 3-4 crushed-flat budweiser beer cans.
2) a used shotgun shell casing
3) A box (FULL!) of roofing nails
4) Enough clay to keep me sculpting the rest of my life.

-Ed