Outside the pool industry, there are other products and processes used to reinforce concrete besides standard rebar and lap splicing. Here, professionals explain why they are not appropriate for pools and spas.
“It’s a problem with equipotential bonding, because with the epoxy, you lose your grid. So you have to, on the shell, add a grid of copper wire at 12 inches on center everywhere, which is expensive, and you’ve paid all this money for the epoxy.
“And if you get one little nick in the epoxy it’ll actually concentrate the corrosion at that spot. Once you start shooting a pool, the shotcrete process will nick the steel. So there’s really no way to shoot epoxy and not have it damaged, in my opinion. So I don’t recommend it at all.” — David Peterson, president, Watershape Consulting, San Diego
“You have to be careful because reinforcement is junk steel, and you can make it worse by welding on it.” — Neil Anderson, principal, Neil O. Anderson and Associates, a Terracon Co., Concord, Calif.
SEE MORE: A Lap for Durability
“It’s incredibly expensive to weld bars, it bears a special certification required, and it’s only done in very special circumstances, like if you were building a nuclear power plant or a big bridge, and you had really big bars and special details. Welding generally weakens the steel. So you might get two bars connected together, but if they’re both weak at that point, then you’ve probably defeated the purpose of the lap. So welding is not really a good option … certainly not in the pool industry.” — Peterson
“They have off-the-shelf mechanical connectors you can use to splice reinforcement. They’re not used very often because they’re not cheap. It’s usually in repair and remodel work. You butt the bars up against each other and there’s a pipe sleeve that goes over the bars with some set screws that screw down and mechanically, just like any coupler, it allows us to butt bars end to end.” — Anderson
“I think for certain retrofit type projects that is potentially viable, but they’re too expensive to use for original construction. But even [for renovations], typically what I’d say is if you’re trying to knock out a wall and make the pool bigger, the way you would do it is you would surgically demolish out more of the concrete than you need to expose, let’s say, 20- to 25 inches of length, then lap the new steel to the steel that you’ve exposed.” — Peterson