For a pool to comply with the Virginia Graeme Baker Pool and Spa Safety Act, it takes more than just connecting two drains to the pump and adding a VGB-approved drain cover. Here are other important steps to ensure that the drains are entrapment-proof and adhere to the federal law.
Each drain cover has been tested to work with a sump of a certain
depth, and the drain pipe sitting a minimum distance below the
cover. If the pipe is too close to the cover, the drain becomes
more susceptible to hair entrapment. In addition, the suction
won’t be evenly distributed throughout the drain.
Consult the drain-cover manufacturer’s instructions to
find out that minimum distance.
If the manufacturer hasn’t provided instructions, the
ASME A112.19.8 standard for drain covers says the minimum
distance between the pipe and the drain cover’s underside
should equal 1 1/2 times the diameter of that pipe.
To make things easier, use pre-manufactured sump/drain cover
configurations when possible. Not only are they easier to install,
but they already come with a properly sized sump. In retrofits, it
may be difficult to do this, since it would require chipping out
the floor to the right shape and completely smoothing out the
Many experts make a good living by correcting the work of other
“experts” whose idea of compliance is slapping on drain
covers that bear the VGB stamp and leaving it at that.
The stamp indicates that the drain has passed testing under
certain conditions, including a maximum flow. Do not base a drain
cover choice on what you have in your truck or the color of the
finish. Instead, select a product that will accommodate the amount
of flow moving though the drain.
When retrofitting, find out the total flow generated by the
pump, and choose covers that can accommodate that total flow. Each
drain must be able to withstand all the force generated by the
pump, in case the other is blocked.
You may find that the pump simply generates too many gallons per
minute for any drain. If so, look into changing the pump.
- Attach the drain correctly
For the drain cover to work properly it must be completely secure.
That means no rusted screws or loose frames.
When replacing covers, the safest bet is to take out the old
frame and install the one that comes with the unit. At the very
least, inspect the existing frame to make sure the right size
screws will lock the cover in place. If the necessary screws are
larger than those the frame was made for, the frame must be torn
Also, if you find that someone before you added new holes to
accommodate self-tapping screws, then replace the frame.
“If we can see that the plastic is still pristine and that
the retrofit screws fit in exactly the same as the original screws,
that we could pull up very hard and not have any movement,
it’s fine,” says John Mortensen, owner of Phoenix-based
Aquatic Concepts. “If we don’t have that situation, we
anchor it to the pool [using a concrete anchor].” He does
this by drilling down into the plaster and shotcrete, and putting
in a concrete anchor.
In his experience, Mortensen has only been able to preserve about
three existing frames out of 100.
A dual-drain system is more than just two drains.
See what not to do when installing dual main drains.