# Pool Deck Issues



## Datadawg (Sep 8, 2011)

Hey guys, noobie here, have been lurking awhile enjoying the communal brain trust. Decided to post and get some advice on a couple issues on my pool build. 

Background: 

I'm in RE dev't business and though mostly have a desk job, frequently make it to the trenches. Have good understanding of trades, mostly thru school of hard knocks. Da wife finally prevailed on me to do a pool. Pool is 48 x 22 gunnite, w/limestone coping and roughly 2,500 SF of 1.25 inch limestone decking to be laid in Versailles pattern using 4 different sized units (12 x 12, 12 x24, 24 x24, and 24 x 36). A pool builder did excavation, forming, steel, plumbing and shot shell (actually he did nothing, subs did all the work). I have a couple field guys that work for me FT, so they will handle the rest of the build (coping, rough electrical, gas, concrete, finish deck, fencing, etc). 

The Problem:

Grade has roughly 3 feet of fall behind pool relative to top of bond beam, so all excavated soil was spread around pool to even things out. My efforts to compact the fill were wasted b/c plumbers came, dug enough trenches to reach Baghdad, and just backfilled -- leaving half the site as raw fill again.

Issues:

1. Limestone - dry laid or on slab? I'm 98% committed to slab (see below), primarily b/c I don't want to deal w/crap growing thru the joints. My 9,000 SF of pavers (don't ask) at the house have enough weeds growing thru them to house Robin Hood and a couple elves. No way I want to deal w/that in a pool. My 2 big concerns w/slab are settlement/limestone cracking and runoff management.

2. To deal w/settlement risk, I decided to do structural slab. The 22 x 48 pool will sit inside deck measuring 76 x 48, so I'll have 14 feet of deck on each side of the pool longitudinally and 12 feet of deck laterally. My guy poured spread footers every 12 feet around the outside perimeter and outside of the pool shell. I didn't engineer the footers, but they were probably 4 -5 feet deep (to reach undisturbed soil 110%) and we formed cage from #5 bar and had two #5 bars extending into piers. Footers were probably 15 x 12 x 18 deep and piers were maybe 10 x 10 inches. I planned to tie all the piers via home brew grade beams (8 inch x 8 inch concrete beam enclosing two # 5 rebars, one rebar 6 inches on top of the other, tied together via perpendicular rebars every 2 feet); the beams would sraddle the piers and would run the entire outside perimeter and inside perimeter of slab, as well as point to point from outside into inside. I tried to post pix, but not sure if they will upload. The slab and pool shell will be separated. 

My question: (1) should the rebar be laid side to side in the beam (horizontally) or on top of one another (vertically)? My guy says he's always laid rebar horizontally, but that doesn't make sense to me; if I want strong beam w/smallest deflection wouldn't I orient rebar so it's acting like a joist (vertically aligned and tied together)? I mean no one would take a 2 x 12 and lay it down as a plank to support a load, you always stand it on edge. What do you all think? (2) Is an 8 inch deep grade beam by 8 (or 10) inches wide suitable to support a slab w/limestone? I know the short answer is call a structural engineer, but the guy we use is a killer (he wanted to calculate weight of dust accumulating on top of HVAC returns when designing SFR framing plans!) -- I will wind up spending a grand and he will engineer supports for Eiffel Tower. PS The span b/w piers is roughly 12 feet and slab itself will be 4 inch, on top of clean 3/4 stone. Of course will compact, using a Wacker 1550 (200 lb machine) -- but it's not going to do much for fill that is 2-3 feet deep. (3) Is using regular remesh 6" OC going to be ok should I use rebar in the slab pour and if so what schedule do you recommend?

3. Runoff Management. Since limestone is being installed in this funky versailles pattern (basically a jigsaw), I can't slope it away from pool -- I don't want to have a ridge line (think of miter cut) where the legth and width of the deck intersect each other. I was thinking of just laying everything level and dealing w/runoff some other way. My options are (1) drill weep holes thru limestone and concrete here and there and have water flow down into the stone and then out via some ABS drain at the perimeter out to daylight in the woods somewhere. The problem w/this is those holes will plug up and the only way to clean them is to push a dowel through. Fine short term, but after 2 years, I'll have a fistfull of compacted crap at the bottom and there goes my system. If I install a deck drain around the entire deck, those things are about $4 PLF materials, so about a grand -- and the wife is sure to give me that WTF routine when she sees how they look. She's a wife after all, what else could I expect on that front?? 

I was thinking maybe run 1.5 " PVC in a loop under the slab and T into it with shower drains every 8 feet or so -- at least they are only about baseball size. I found a supplier in Hong Kong that sells really neat copper and stainless steel grates, so they might look spiffy. But maybe I'm overthinking this and someone here's found a better way to deal w/this, so pls give me some ideas. 

Final concern is how do I eliminate cracking of limestone due to different thermal properties w/the slab? In ideal world, I'd saw cut an expansion joint into the slab right under a grout line, so the expansion/contraction would be controlled at the same point. But given that versailles pattern, I can't imagine how to coordinate expansion joint on slab w/limestone above. 

Edit: I tried adding a couple pix 5 times now, but they are not uploading. I'm not very capable w/computers, so I'm giving up. Maybe the pix I have on my computer are too large or something.

Thanks a lot for the advice and guys, please don't flame me if I've committed any sins so far.


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## lukachuki (Feb 11, 2005)

Datadawg said:


> Edit: I tried adding a couple pix 5 times now, but they are not uploading. I'm not very capable w/computers, so I'm giving up. Maybe the pix I have on my computer are too large or something.
> 
> Thanks a lot for the advice and guys, please don't flame me if I've committed any sins so far.


email me your pix to lukachuki(at)gmail.com and I will put em up for you. Sounds like an interesting project.


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## Datadawg (Sep 8, 2011)

lukachuki said:


> email me your pix to lukachuki(at)gmail.com and I will put em up for you. Sounds like an interesting project.


Will do, thanks for the assist.


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## lukachuki (Feb 11, 2005)

Pics for the OP with his captions!

Pic 1

"Dig in process. Wood form in back right corner shows fill level; string
line running toward trackhoe shows elevation drop and amount of fill to be
added in rear of pool (3 feet +/-)."


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## lukachuki (Feb 11, 2005)

Pic 2

End of dig, fill dirt @ rear of pool compacted via 40,000# trackhoe running
back and forth.


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## lukachuki (Feb 11, 2005)

Pic 3

"Lengthwise view of rear of pool. My compaction goes out the window, thanks to a couple mini excavators digging up trenches for plumbing runs. Not to be outdone, I foolishly used my John Deere backhoe (didn't have trencher) to dig trenches for electric conduit. Machine had 24" bucket, so most of the dirt underneath to be built deck is disturbed."


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## lukachuki (Feb 11, 2005)

Pic 4

"Gunnite Shell"


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## lukachuki (Feb 11, 2005)

Pic 5

"Footers on the backside of pool. Distance b/w them is about 12' OC. Not
formed or pretty, to say the least."


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## lukachuki (Feb 11, 2005)

Pic 6

"Excavation for grade beam. This is on the side of pool w/not much fill
(maybe 8 inches). Piers are 12' OC."


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## lukachuki (Feb 11, 2005)

Pic 7

"Can just make out rebar for grade beam near forms on bottom of photo."


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## lukachuki (Feb 11, 2005)

Pic 8

"Limestone coping. Column that's clad in travertine also contains wired spa
control. Pool builder told me he's never put it on column, and puts in
right on the pool deck (the better to trip over the thing and have some 250
lb football player step on it -- makes total sense to me). The limestone
tile going on deck is same material as coping, only 1.25 inches vs. 2 inches
thick."


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## lukachuki (Feb 11, 2005)

Pic 9

"Schematic of limestone layout"


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