Best way to determine the thickness of the bottom of the pool shell

[grifftek]

Hi

Does anyone know the best way to determine the thickness of the bottom of the shotcrete pool shell. The shell has not been plastered yet.

I have some exposed rebar in the bottom of the pool and while repairing it found out that the thickness in that area is only 3-4 inches. I would like to determine if this is just a localized condition or if the whole bottom is too thin. Pool plan states bottom thickness to be 6 inches.

Im thinking that I could roto-hammer some some 1/2" or 5/8 holes with the depth stop set at 5 inches. If I don't punch through assume that I am close enough to the 6" thickness. Afterwards, I could fill the holes with hydraulic cement, rapid set, mortar? The larger 5/8 hole would be easier to fill than a smaller holes.
Anyone have any advice / other ideas?

Thanks
Bill

 

[Melt In The Sun]

Well, that would certainly work. Is this a DIY build, or is there a builder accountable?

I wouldn't think you'd even need to bother filling the holes, the plaster crew can do that.

 

[grifftek]

Well, that would certainly work. Is this a DIY build, or is there a builder accountable?

I wouldn't think you'd even need to bother filling the holes, the plaster crew can do that.

Not a DIY build. The pool was built in 2008 but was never finished. Pool builder has moved to another part of the state. I did make an effort to have him finish the pool last year but wee were not able to reach an agreement on the price.

And after checking out his installation and electrical hook up of the pool equipment, probably just as well.... Pool lights were mis wired (my 15 year old could have figured that out) and the 2 speed pump wiring was laughable! It would have burnt up the motor and or relays. The wiring diagram is right there on the control, no excuse for this!

After pressure washing the pool a couple weekends ago in preparation for having it plastered, I noticed that there was a small area where the rebar was showing. during the process of chipping out around the exposed rusted rebar I found the shell thickness in that area to be no more than 4inches thick. This left my mind to wander and think the worst that the whole shell was this thin.
Over the weekend I drilled 10 test holes in the shell and found that the depth of the shell appears to be about 5 inches thick. While this doesn't meet the plans depth of 6inches, im not sure there is a cost effective solution that makes sense.

If it were 3 to 4 inches thick I would epoxy in rebar and tie together a 12" grid and pour new concrete over it. but from the information I have gathered adding all of this additional weight to the bottom may affect the sides of the pool as they are not engineered to hold the additional weight.

My current plan is to repair the exposed rebar area and do a good white plaster job and try an get some enjoyment out of the pool for a few years (after 6 years of looking at an empty pool)

Thanks for your response!

Bill