Dennis

Beware of an installer named Jumper in this area.

I installed my fiberglass pool with the intension of installing a sandstone coping and deck. I place concrete around the pool and then wondered how to set the coping on the fiberglass around the perimeter. Some said silicone and others said construction adhesive. I did not see how this could last. I set out to find a better more durable method. This is what I ended up doing: 1 Sand area to be covered with 60 grit sand paper, all glossy surfaces should be removed 2 Purchase a high quality waterproof 2 part epoxy thin-set, install on fiberglass using 1/4" notch trowel 3 After epoxy has cured install coping using correct method for material you are using This gives the grout something to hang on to. I thought about using epoxy to set my sandstone coping but it would be way to expensive due to the different thickness from stone to stone. If your coping is a consistent thickness, setting them with the epoxy should work fine. Talk to your tile guy and make sure you get the right kind of epoxy. I am happy to say my sandstone is holding on just fine. Dennis

My advice would be to consult with a Structural Engineer. Most concrete crews understand the basic concepts of placing concrete and are generally not qualified to give engineering advice. My experience with contractors is they want to do as little as possible and you should give exact details of all work to be done. Under the circumstances you described the extra cost would sure give you piece of mind.

American Fiberglass Pools A Houston, Texas FG builder. They have been around for a long time. The pool they built for me has a tan granite coating.

So you think just putting rebar (only) around the perimiter would not add to the strength, in fact might encourage cracks? The perimeter would not deflect as much as the center section, so Yes.

You want to use the same size reinforcement throughout the slab so that you have uniform strength. Using rebar in some areas and mesh in others would allow the slab to deflect at different rates. Cracks will probably develop at the point where the rebar stops and the mesh starts. I would use #3 bars (3/8") spaced a min. 12" on center; 8" would be best for a 4" slab. If you have to lap bars the rule of thumb is 40 times the bar diameter. In Texas the material cost would be about $50 for a 8'X8'X4" slab.

I only gave basic information so one can understand the basic concepts as to the need for concrete reinforcement. Masonry experience is not relevant to sound structural engineering practices. You make some interesting statements; I hope you gained some insight on concrete reinforcement. If you do not grasp this concept, compared to all the other expenses of placing concrete adding steel is cheap.

It would be difficult to say when the slab will fail. It depends on the soil under the slab and I do not know what you have clay, sand, rock, ect. It might last 1 year or it might last 10. But I can say that it will fail at some point. Will it support a spa, probably so? Will the spa have problems because of a failure I don't know? My point is that a concrete structure need to be reinforcement contrary to what any one else has stated previously.

So if he didn't put ANY reinforcement in it, am I screwed? I'm just trying to picture how the slab could fail with such a spread-out load on it.... Under compression concrete is very strong. That is why bridges have pre-stressed girders to carry the load. Under tension concrete has very little strength. So when you look at how a slab will be loaded you will have areas that are under compression and areas that are under tension. Without reinforcement there is not any thing to hold the concrete together. In short all concrete structures require reinforcement to carry a load without failure.

Concrete strength is dependent on the reinforcement (rebar, wire mesh, fiber mesh, ect.). Without reinforcement concrete has very little strength. If you have sufficient compacted base under the concrete you may be okay until the base moves, concrete is plenty ductile and the base would have to move quite a bit.

American Fiberglass Pools A Houston, Texas FG builder. They have been around for a long time. The pool they built for me has a tan granite coating.

adwh, with all due respect, I do not think you know much about fiberglass. Example; my father was in the fiberglass boat business for almost 50 years. In the mid 60's my uncle had an above ground open top concrete tank on his ranch (I would guess it is about 50K gallon and yes we swam in it). The tank was leaking so my father and uncle lined it with fiberglass (hand laided, two layers of mat and one wovern roven, not sprayed with a chopper gun). The only thing that has been done to this tank over the past 40 years is 4 or 5 coats of gel-coat have been applied. If properly applied and maintained fiberglass should last a very long time. I don't know of many chemicals that will hurt fiberglass. The biggest enemy is UV so it has to be protected. The tank is located in West Texas and I was out hunting by it this last fall so I have seen it recently. My point is I don't understand your comment about fiberglass not being able to last 20 years. Please provide proof to your comments.

IMHO you should do some research on a fiberglass pool. There are lot of pro and cons to all types of pools. Be sure to get some references from your pool guys that go back 5-10 years.

I am putting in an in-ground fiberglass pool. I have to build a retaining wall due to the grade. The retaining wall will be about 3-4 foot above grade on the backside. I want to put my pool equipment behind the retaining wall to hide it from view. Therefore, the equipment will be about 2-3 foot below the water level. Should I use a conventional type in-ground pool pump or is there another type pump that should be used for this type installation since there won't be a need for a self priming pump. I am also building a rock waterfall feature. What type pump configuration is required for a water feature? This installation is a (16X34 3-1/2 to 5-1/2 deep) DIY with the pool manufacture doing the pool set. I will be contracting and doing the rest myself. Any recommendation and help would be appreciated.