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  Bill Conant September 15, 2011 at 5:26pm

  Have you costed out entire demo ,re-tie, re-shoot? You start with a clean slate, perfected engineering and hydrology and built "your way". Three days with an excavator mounted hammer (a skidsteer mounted hammer down in the hole may be better or just keep the excavator far enough from the edge or ....gulp), bolt cutters, acetylene torch a Bobcat and two 10 yard dumptrucks, Starbucks and Redbulls for all, and viola ready for anything. I know dump fees have gotten crazy but that isn't your fault. D.I.Y. or have a demolition co bid it. Depending on dump fees I would guestimate 12K for demo by others. 10 K to re-tie,(very dependant on design) 20K to reshoot(ditto). Interior and plumbing are pretty much a wash ( your doing that anyway) same for Equipment set . Drains, lights, returns, steps and swimouts where they belong, not where they happen to be. Add a 10K( or more!) builder fee and sleep easy. A bomb-proof beam. A better finished product and completed more quickly. Be advised CHECK YOUR OWN NUMBERS, as I am totally shooting from the hip, but kinda close. Would probably need additional engineering spec'd for disturbed ground.

  So, OK, fire away, I can take it. (smiling)

  p.s. I love the amazing cross-section of people found here. You guys and gals are great.

  p.p.s. But even so,blast away at my premise.

  Peace,

  Bill
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  Adam M. Heath August 11, 2011 at 4:45am

  I read through this entire string and would VERY interested in hearing how this project went!  I've flirted with doing this in the past and shied away from it for the cold joint reasons. 
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  Kevin Woodhurst March 2, 2011 at 7:02am

  Great Info Rob... and spot on...
  
  Rob Lane said:

  1.  1025/15 s.f per person=68.333 people x 2 cubic feet each=136.666 cubic feet static surge capacity.

  136.666=140 x 7.5 gal per cubic foot = 1050 gallons of static surge capacity. This is a minimum nimber, not a target number.  County clubs bring all the pipes to the surge tank and put float control on. They also use small jet fittings inside the gutter to push problems down hill. How do you plan to smooth the interior of the gutter? This would help the flow charistics of the gutter.

  2. Check local codes for s.f per person. 

  3. Gravity flow can only be 3 feet per second. This is sewer regs.

  4. Dynamic surge (swimmer waves, cannonballs, etc...) will tend to run right past a 1/2" slot over a gutter trough. Possibly you could slope the first three feet of deck back towards the slot. Typically this requires a code variance.

  Good luck, Rob
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  Rob Lane March 1, 2011 at 11:58pm

  1.  1025/15 s.f per person=68.333 people x 2 cubic feet each=136.666 cubic feet static surge capacity.

  136.666=140 x 7.5 gal per cubic foot = 1050 gallons of static surge capacity. This is a minimum nimber, not a target number.  County clubs bring all the pipes to the surge tank and put float control on. They also use small jet fittings inside the gutter to push problems down hill. How do you plan to smooth the interior of the gutter? This would help the flow charistics of the gutter.

  2. Check local codes for s.f per person. 

  3. Gravity flow can only be 3 feet per second. This is sewer regs.

  4. Dynamic surge (swimmer waves, cannonballs, etc...) will tend to run right past a 1/2" slot over a gutter trough. Possibly you could slope the first three feet of deck back towards the slot. Typically this requires a code variance.

  Good luck, Rob
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  GRANT OSBORNE January 17, 2011 at 6:58am

  We work on 12% pool volume for our tanks for sand filters and 8% for cartridge filters for our calculations. If any help.
  
  Rick Larson said:

   Very cool design but I can't help wondering where the splash out will go. Although the vanishing edge look is nice, in this scenario you need to have some form of grating around the perimeter to catch the waves etc. that will be created when anyone is using it. Under the grating can be an entire perimeter surge tank as I mentioned earlier or a shallow one leading to whatever surge setup you will have.

   

  How big is the pool? You are probably going to want surge capacity of something like 15 gallons per swimmer minimum and each foot of perimeter will need about 4-5gpm to have a nice flow. With a 20x40 pool that could be up in the 500gpm flowrate which could require maybe 3 - 12x12 or 5/6 - 9x9 frame and grate main drains. Also looking at 6" pipe to carry that flow nicely.

   

  Anyways, very nice concept and a few numbers to mull over.
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  Dwayne Lalande January 12, 2011 at 9:39pm

  Wow! Thank you everyone for your valued input! The surface area of the future design is 1025 sq ft.

   

  My plans are to run Pebble Tech to the edge. Then, continue the inner wall of the gutter with black granite to insure I have the ability to tune it to almost a 0 tolerance, same principle as Dave mentioned.

   

  I'm still working on the hydraulics, but intend to run the edge with a VF 3 hp pump. The 3 hp setting will be dedicated to the spa only. During normal pool operation the pump should only run between 1.5 - 2 hp. I definitely have all calculations checked by an engineer who has worked with me on previous weir projects.

   

   
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  Kevin Woodhurst January 12, 2011 at 9:08pm

  I have used 1/2 to 1 GPM per foot for flow with no problems... There are many things to get near perfect on these pools, the stone is a good idea because as was stated it can be ground down. I have used stone, tile and an aggregate finish and we still have been able to work with the tolerances to provide the effect with no issue's.

   

  However as stated previously I am always safe than sorry and add the additional plumbing for redundancy and piece of mind.

   

  15-20 GPM over 120 feet would require pumps capable of producing a flow rate of 1800-2400 GPM, good luck with that, even 5 GPM is over 1000 GPM.

   

  At a reasonable 1 GPM per foot you will need 120 GPM which is doable with a single pump for the overflow feature. Make this pump dedicated and be sure to filter it.   

   

  I like the idea of running smaller pump(s) and maintain the tolerances, your clients will be happier that way as well...

   

  Water leveler goes in the surge tank and you will want to be able to gain access to the tank as well which of course is gravity fed from the overflow trough/piping surrounding the pool.

   

  Additionally I would use separate pumps for your features, IE... Spa jets, water feature etc... and obviously add automation.

   

  Does the current pool have an in-floor cleaning system system? If so do you plan on keeping it?

   

  Kevin... 

   

   
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  David Penton January 12, 2011 at 8:39pm

  Not trying to pick a fight here!  Just providing information.

   

  I am aware of a residential pool with 200' of edge running on a single 3/4 hp pump...

   

  The desired effect for one of these pools is very subtle water movement over the edge, and you wouldn't want a torrent of water overflowing the edge.  At 500 gpm you are looking at a 1" wier depth on a 20x40 pool.  At that flow rate you would have difficulty even getting that amount of water through a typical 1/2" wide slot.

   

  Often these pools are built using Natural Stone as the "wet coping" material so that slight imperfections can be fine tuned with a grinder in order to maintain the desired edge tolerance (which should be as close to perfectly level as possible)...

   

  Within the high end pool building community 1/2 gpm is the accepted target flow rate for the edge detail...

   

  We are currently working on a design with about 190' of edge which should be able to run with a single 3.0 hp VFD pump and 4" plumbing.  Again it all comes back to the skill of the installer and how perfect the edge itself is.  There is a reason why these pools aren't cheap!

  I do though agree with Kevin... if you are unsure of the skill of the coping installer, then it's not a bad idea to have a backup system in place that you can utilize if necessary... Just make sure it has large enough plumbing.

  
  Rick Larson said:

  Yes, I have seen the edge torn off and replaced more than once on new pools to get it level. As for flow, I have heard of some recommending designing for up to 15-20gpm which would be huge flow. At the same time I think designing for 1/2gpm is wishful thinking on 20x40 perimeter. The 6" pipe I mention is for suction in a gutter surge tank design. Gravity to a remote surge tank would be of course much larger.
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  Bruce Wettstein January 12, 2011 at 8:22pm

  I agree, David's tolerances are spot on!  All V-Edge and perimeter overflow pools should be built to these tolerances. There is no reason that a pool of that quality (any one, for that matter, but there is more "cheat" in regular pools to make this up at tile and coping) should be built to anything less. 

   

  These are still unique pools, and those building them should strive to do the absolute best quality work that can be had.  The homeowner, and the industry, expects it.
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  Kevin Woodhurst January 12, 2011 at 8:01pm

  Absolutely, on the skill of the installation of the wet areas for flow purposes, that is a big pool and the closer you can get to David's number the better off you will be...  Get as much input as you can on this and use recommended resources for hydraulics if only for a second opinion and verification of your own or a 3rd parties calculations.

   

  For the record whether needed or not I think it is a reasonable idea to add an extra suction and return run for an additional pump if needed later just in case...

   

  Great input everyone!!!

   

   

  Kevin...