Of all the things I’ve learned in my work as a watershape designer and builder, one particular point stands out: When it comes to ensuring quality results and a project’s success, there’s absolutely no substitute for good supervision!
I say this knowing that most job sites run by people in the pool industry are inadequately supervised if they’re supervised at all. Yet experience shows, time and time again, that while complete, professional plans are part of success and that great subcontractors are essential, constant oversight is the absolute necessity. And when good supervision is paired with open communication and a detailed understanding of clients’ needs, everything is in place for success on all levels.
I’ve mentioned this all before, of course, but it bears particular emphasis in approaching the kind of project I’ve been discussing in the last two “Details” columns. My clients built a magnificent, architecturally significant home right next to a thoroughly mediocre pool, and in “remodeling” it, I’m well aware of the standards they’ve set and the quality they want to see radiating from every step of the construction process.
My steady presence on the job site assures my clients that all is going as we have agreed and according to plan. At the same time, it gives my subcontractors ready access to information they need to do the job right the first time through.
Last time, we looked at demolition and our work up to the point of framing a new wall for the old pool. This time, we’ll move past forming to look at plumbing, steel and guniting – points in the process where the “guts” of the installation are being developed. As is true with all other project phases, precise execution here is critical – and is, in the case of this project, our success is the direct result of my supervision of every detail.
|The key to marrying the new wall to the existing pool structure involved overlapping new and old steel between them in both directions. We worked with the engineer’s plan in creating a network of rebar that makes up the new pool’s bond beam.|
To refresh your memory, we’re rehabilitating an old, rectangular pool that was completely out of scale for its surroundings. In so doing, we’ll be working with a rich palette of aesthetic touches later on, but for now we’re doing the hard work of reshaping the vessel by narrowing its width, raising its floor and adding a large spa.
As the new wall and the spa were being formed, my plumber was busy re-plumbing the entire pool – including a new skimmer and main drains, six return lines, suction and bleed-off lines for the waterfalls, lines for the other waterfeature effects and a stub for a pool sweep. We pressurized all these lines to 40 psi per local building codes.
|We doweled steel into the old floor, using hydraulic cement to secure the rebar in place (above). There was plenty of drilling involved by the time we finished setting up the new wall, the pool-length bench and the grid for the new floor (left).|
As I’ve never hesitated to admit, my colleague and Genesis 3 partner Skip Phillips has taught me most of what I know about hydraulics in the past six years. Even though many of you see me as a relentless know-it-all and an arrogant, elitist pig, I’m never ashamed to say that hydraulics wasn’t my long suit until I met Skip. I don’t want to chase this tangent any farther than to say there’s nobody in any of the watershaping trades who can’t benefit from education!
Skip beat on me until I accepted the fact that pipes and filters are generally undersized and that pumps are typically oversized – basically creating systems that can’t work very well and that are indeed doomed to fail sooner rather than later.
The industry at large has fallen into these deplorable practices because so many of us (and I’ll include myself here) do not come to the job with an advanced understanding of hydraulics. Applying what I now know, however, I use 3-inch suction lines, 2-1/2-inch return lines and split main drains (for safety). (As another aside, it bears mentioning that if you really understand hydraulics, the suction-entrapment issue usually goes away.)
As was mentioned last time, we removed the concrete from the old bond beam for not less than 24 inches where the new wall intersects with the old shell. With the old steel exposed and cleaned, we tied the new wall’s beam of six new #4 bars (1/2-inch diameter) into the old shell’s beam and bent the old steel over into the new wall – a “44-diameter lap” my structural engineer specified to securely tie the new wall into the old structure.
|With the forms, plumbing, steel and newly raised floor all in place, it was time to shoot the new wall, floor and spa (right). We never use rebound: Getting rid of it isn’t any fun (below), but it’s required for sound, quality construction.|
Behind the curtain of new steel, we’d already built a formed wall of two-by-four construction braced with all the heavy-duty kickers it took to make the wall completely stationary. We lined the inside of this form with plywood – no button board or anything else that might flex or move. We also line our plywood with Masonite or plastic to make stripping easier; in this case, we used plastic.
As work went ahead with the steel for the new wall, we were also setting up the steel for new benches that stretch along the length of the pool closest to the house. As I’ve mentioned before, all my benches are formed with steel, never from concrete alone – and absolutely never with rebound. In my book, people who try to save money by using rebound for anything in a pool are asking for trouble – and cracking. It’s substandard construction, and it should not be tolerated.
We also formed up a new spa in the shallow end of the pool where the old entry steps had been (see the sidebar below for details on this part of the project) and prepared for raising the pool’s floor by as much as five feet in the deep end.
To raise the floor, we doweled new steel into the existing pool floor and locked the bars in place with hydraulic cement. Per the engineering plan, we used #4 rebar on 18-inch centers, both ways (OCBW) at 12-inch elevations, creating multiple curtains in the deep end. All of this steel is required to prevent shrinkage and cracking and to give the floor of the pool the structural strength it needs.
Before shooting the pool, we filled the bottom with poured concrete – stopping about eight inches shy of the last curtain of steel. That gap was to be filled with gunite when the time came to shoot the new shell and spa.
SHOOTING THE SHELL
Once the plumbing was in place and the steel had all been tied, it was time to apply the gunite. It was a pretty straightforward shoot – nothing radical by way of configurations and just my usual tight tolerances. In all, we used approximately 32 cubic yards on the shell – not including all the concrete we’d poured to raise the floor.
A Spa on the Side
I build spas for comfort as well as looks.
In this case, the clients wanted a large spa added to the pool – a 6-1/2-by-9-foot rectangle. That worked for me, because unless otherwise requested by the client, I believe that spas should be approximately 50 square feet and at least 6 feet wide to accommodate two people sitting across from each other without banging their knees. No problem here on that score.
The spa is elevated 20 inches above the pool surface and sits partially in front of the old retaining wall. The wall (which we’ll discuss in much more detail in an upcoming issue) sits atop the original pool’s bond beam, and we wanted to keep it as a key architectural feature. We could have lowered the wall to reduce its visual weight, but instead we raised the level of the spa to make the space seem less confining. In addition, the back wall of the spa itself is 17 inches thick – a comfortable seat that will give us a generous surface for showing off the spectacular tile we’ll be using.
The spa itself will have 16 jets, with eight for back therapy; four calf jets and four floor jets for foot massages. These jets have been set up on two separate manifolds with two booster pumps and two blowers – one system for the back jets, the other for the calf and floor jets. I use two systems to add flexibility to the jet settings: Splitting the function of the jets in this way enables the homeowner to enjoy multiple jet effects.
With the booster pump on, for example, the user gets a light application of hydrotherapy action. Kick on the blower and it’s much more active. With 3-inch suction lines moving the maximum amount of flow, we’re able to create the a great deal of turbulence – again, giving the homeowner a variety of effects from subtle and soothing to dynamic and active.
By the way, I love foot jets and build them in for clients whenever I can. After all, one of the best things in the world is a good foot massage, and what could be better for enhancing the spa experience?
Once the pool had been shot, we let the shell hydrate for 14 to 18 days. This is important because gunite, like all concrete, gains approximately 80% of its strength in the first 14 days after application – and picks up the remaining 20% of that strength very gradually for the next 100 years or so.
|With the forms stripped and the new spa and wall firmly in place, we backfilled the obsolete section of the old pool – and set the stage for an amazing transformation of the pool, its yard and the entire setting.|
The more water is present during hydration, the stronger the gunite will be, so we keep it wet: We’ll set up hoses around the pool and turn them on and off periodically ourselves – or set up solenoid valves to get the job done. As this point, the electrician came on site and set all the conduits for the pool lights, control systems, landscape lights, the outlets needed for the barbecue – and anything else that required electrical connections.
Once the gunite had set, we stripped the forms and dropped 45 tons of clean, 3/4-inch crushed rock as backfill behind the new wall. On top of that, we added a layer of compacted fill to bring it up close to grade.
Now the fun starts.
Next time: a look at setting the stage for the aesthetic details that will make this installation a knockout.
David Tisherman is the principal in two design/construction firms: David Tisherman’s Visuals of Manhattan Beach, Calif., and Liquid Design of Cherry Hill, N.J. He can be reached at [email protected] He is also an instructor for Artistic Resources & Training (ART); for information on ART’s classes, visit www.theartofwater.com.