Opening the Well Point on Concrete Pools
Serious swimming pool repair procedures like plastering, re-piping and re-tiling all begin by draining the pool.
This can be risky if you are not aware of the ground water threat in your area. You get a very good idea of the ground water elevation when you live on a lake or retention pond.
(photo right) Owners on this retention pond can expect to hit ground water at about 3 feet.
If you were to lift your pool out of the ground, it would resemble a boat.
Not a speedboat perhaps, but a floatable boat.
The weight of water is what holds it in the ground. If you empty the pool without doing anything about the water it's sitting in, you may find out just how well your pool does float.
In the plastic sump under most pool main drain grates sits a common, threaded PVC plug.
(photo left) A simple tool called a 'plug wrench' or two wrenches; one secured to the plug, one used to turn the first wrench, will remove this plug.
With the plug removed, ground water is free to enter the pool bowl.
Plumbing a self-priming pump (any standard pool pump) to this well point opening (oran optional wellpoint pipe that may explain a ground level 1.5" capped line just off the edge of the deck or a capped pipe standing anonymously near the equipment- photos of each are on the Pool School PRO CD: Ed note) will pull all available water out from under the pool (Covered later in this chapter).
Under the deep end of most pools is a three or four foot thick bed of gravel- sized rock placed there during the original dig.
This rock bed allows the free flow of ground water and, by pumping out the water that collects in the bed, you keep the hole, and the surrounding area, dry.
Drive a pry bar, long screw driver or (as shown below) a scrap of #3 rebar into the well point vent to make sure its open and free-flowing. Ground water will always flow either into or out of a cleared wellpoint in a drained pool.
Among the roughly 3,000 pool contractors in Florida, about 30 pools are popped every year.
One unlucky (consistenly incompetant) company lost three pools to the same thunderstorm. Its unknown how many other pools 'pop', but more than one pool weve visited had been drained by a well meaning handy man who had no idea of the risk he was running.
When the pool is finally drained, turn the pump off and let ground water enter through the well point. If water doesnt come up more than a foot or so, you can safely prep the pool and plug it immediately prior to resurfacing and refilling; assuming no heavy rainstorms intrude.
If the water comes up any higher than the break so that a sump pump has to run constantly to keep up with the flow and the pool is to be drained for a day or more, the pool should be well- pointed with a self- priming pump (any pool pump) and ground water forcibly withdrawn. (Also covered later in this chapter)
In areas where a high water table is known or suspected, post hole diggers can be used to dig a hole near the deep-end deck edge to expose ground water to about 4' below ground level or what just happens to be the same depth as the shallow end of most pools. In this case it would be reasonably safe to drain the pool down to the shallow end.
If it's necessary to drain the pool further, you can drill a 1/2" hole through the pool floor at increasing depths (every foot or so) until you find the water table, evidenced by a spouting water flow. Relieving this pressure with a sufficient number of holes to reduce pressure to a steady stream, will make it reasonably safe to finish draining the pool.
Pull the well point plug as soon as possible and any cement can be used to seal the test holes.
Pools that lie in extremely high water table areas where water can be found within 2' of the surface or when dealing with inground fiberglass, steel or vinyl liner pools should be well pointed with a self priming pump connected and running long before any water is removed from the pool.
(right) This photo illustrates every poolmans second worst nightmare.
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