Middle of Build. Any issues? Plumbing inside of concrete

[DFWPoolNewb]

Hello. I am in the middle of a build and things seem to be moving along well. I have gained a ton of knowledge on this forum but am still new to this process. The pool co recently put down rebar and plumbing and things look ok to my eye. But someone pointed out to me that it’s a big problem that I have plumbing that will be embedded in the pool shell. Below is a picture. Any truth to this? What are the chances this creates a problem? Just trying to decide if I need to ask them to come back and fix things and if so exactly what I need to request.

Aside from that issue (assuming it is one) anything else you can identify? Pool is in DFW area if that matters.

Appreciate your insight.

 

[PoolGate]

??? Where else is the plumbing supposed to go? Your pic looks like every other pic of a pool build. No issues that I see.

 

[Newdude]

Aside from that issue (assuming it is one) anything else you can identify?

I am never a fan of flex PVC. Termites eat the wood fibers used as filler, or it can collapse if it clogs. It doesn't happen to every setup, but once that plumbing is buried under the patio or encased in the pool shell, you don't want to even think about it for 40 years.

It is of zero benefit to you, and only saved the PB an hour of labor, so it really didn't do much for them either.

 

[JoyfulNoise]

Typically speaking, “best practices” dictates that one should avoid putting anything into the concrete that isn’t cement and aggregate. So the take away from that is, where possible one should avoid burying pipes in the concrete shell. It basically adds a “void” into the concrete matrix that weakens it on that area. Is it necessarily always a problem? No. But it adds to the possibilities that cracks can develop and penetrate the concrete. That being said, almost every pool builder violates that “best practice” and it’s rare to see buried PVC cause any damage on its own. As long as the ground around the pool is stable and the proper engineering plans were followed AND all the plumbing is pressure tested BEFORE it is encased in shotcrete, then it should be fine.

The only other option is for all the plumbing to be ripped out and redone with a couple of large trenches around the pool to carry the pipes. That has its drawbacks as well. Mostly notable - the PB is not going to agree to redo all the plumbing.

 

[HermanTX]

+1 with the comment that some of the pipe looks like Flex PVC which should be avoided, if possible. You may want to discuss that with the PB. Their comeback will be that using Flex PVC avoids the use of 90 deg elbows to make turns. It may be too late but it is worth asking.

Did the PB provide a plumbing layout?

Now that you have started your construction thread, put a picture of a rendering what the final project will look like.
Also, include a list of the equipment to be used.

 

[tommelton]

I don't see the flex PVC, I see what looks to be heat bent rigid PVC. Just curious where you see flex?

 

[Newdude]

I don't see the flex PVC, I see what looks to be heat bent rigid PVC. Just curious where you see flex?

It very well could be rigid, the image is a little grainy. Nice call.

 

[ajw22]

Your PB is to cheap or lazy to trench outside the pool to run the pipes outside and only bury in the shell the runs to the penetrations. You want to minimize the glued joints that are buried in concrete.

Will it be a problem? Maybe, maybe not.

You can discuss it with your builder.

Make sure they do a good pressure test since it will be difficult fixing any poorly glued joints.

 

[JamesW]

The plumbing should not be in the wall.

The only plumbing in the concrete should be perpendicular to the wall for necessary plumbing.

Plumbing pipes that are parallel and embedded in the concrete create weak points.

The placement of plumbing in swimming pools is another critical area that can create a weak section in a wall or floor (Fig. 3).

The plumbing needs to be set back far enough or even outside of the pool so that it will not impair the structural integrity of the pool shell.

Again, you need to be able to have proper coverage on both sides of the reinforcing bars to make sure there are no weak points in the walls or floor.

https://shotcrete.org/wp-content/uploads/2020/04/2018SummerShotcreteEMag.pdf

https://shotcrete.org/wp-content/uploads/2020/05/2018Sum_Reeves.pdf

 

[JamesW]

Pipe placement in concrete pool wall

Does anybody know if placing this much pipe together normal? I would think this is going to create a void and weak spot in the wall. Even rebar can’t be this close together to allow for concrete coverage, and I would think the plastic pipe may cause the wall to fail. this is an owner build but...

www.troublefreepool.com

Plumbing pipes should never be embedded in the gunite/shotcrete swimming pool shell because the pipe creates a thin structural section at the pipe location where cracking can develop.

https://iibec.org/wp-content/uploads/2016-bes-holmer-phifer.pdf

 

[JamesW]

Shotcrete or gunite has many different requirements to be strong and not develop cracks.

The concrete should be 4,000 psi, or higher, the rebar needs adequate coverage etc.

Without adequate coverage, the concrete is too weak.

You should have an engineer who has specified the requirements for things like rebar size, placement, coverage, concrete thickness, compressive strength in psi etc.

The engineer should be consulted to get their input on the placement of the plumbing.

The shell should also be watered as per instructions.

Shotcrete is routinely engineered and placed to create a watertight swimming pool, which the industry generally agrees, requires the structure to have a minimum compression strength of 4000 psi.

Even extending wet curing time from three days to seven days after the concrete or shotcrete is placed, can further reduce surface shrinkage cracks by 10 to 20 percent.

Ideally, the NPC recommends that moist curing (spraying with water) continue once a day thereafter for 28 days, and recommends “soaking” the concrete or shotcrete three to five times per day for the first seven days, depending on the climate in your area.

Soaking is usually done by spraying the shotcrete or concrete surface with a garden hose by the homeowner or whomever is assigned the responsibility.

https://www.nationalplastererscouncil.com/wp-content/uploads/2022/06/what-happened-to-my-pools-interior-finish.pdf

 

[DFWPoolNewb]

Hello. I am in the middle of a build and things seem to be moving along well. I have gained a ton of knowledge on this forum but am still new to this process. The pool co recently put down rebar and plumbing and things look ok to my eye. But someone pointed out to me that it’s a big problem that I have plumbing that will be embedded in the pool shell. Below is a picture. Any truth to this? What are the chances this creates a problem? Just trying to decide if I need to ask them to come back and fix things and if so exactly what I need to request.

Aside from that issue (assuming it is one) anything else you can identify? Pool is in DFW area if that matters.

Appreciate your insigh

Here is an image of the plan along with the equipment listed. Pretty sure it’s going to be a bit of a fight on the plumbing issue so we’ll see what they say. I have a call with them setup later today so we’ll see what happens.

 

[ajw22]

The shell should also be watered as per instructions.

Watering New Gunite and Concrete - Further Reading

www.troublefreepool.com

 

[DFWPoolNewb]

Update: PB swears this is the best way to do it, pool is structurally sound, etc. Confirmed that they repeatedly pressure test to make sure everything is good. Not sure what I can do at this point. Probably very costly to have things redone. Probably more costly if a wall collapses or something 6 years from now. Also confirmed that they didn’t use flex PVC

 

[JoyfulNoise]

The plumbing should be sealed and pressurized with water. Once the plumbing is confirmed to be free of any leaks, then the gunite crew can come in and shoot the shells. The plumbing should remain pressurized during the shotcrete process and the pressure should be monitored before, during, and after the shell is complete. As long as the pressure holds, then the plumbing should be good.

Pool shells very rarely crack and when they do it’s usually due to significant ground movement or shrinkage of clay soil. As long as you soil condition was taken into account in the design, I think you will be ok.

Is burying PVC pipe “non optimal” … sure. Is it a catastrophic defect of the process that requires weeks of delay in reworking …. No. Builders do this all the time around here where I am and pool structures are generally long lasting. We have lots of old gunite pools with buried piping …

 

[JamesW]

I recommend that you take extensive pictures with reference points so that you can figure out if any future cracks line up with the plumbing.

I would not want the plumbing in the wall.

It essentially creates a control joint that will relieve any stress by cracking along the line.

Do you have an engineer assigned to the project?

If yes, see what they say.

 

[DFWPoolNewb]

I recommend that you take extensive pictures with reference points so that you can figure out if any future cracks line up with the plumbing.

I would not want the plumbing in the wall.

It essentially creates a control joint that will relieve any stress by cracking along the line.

Do you have an engineer assigned to the project?

If yes, see what they say.

I haven’t been working directly with the engineer. And in Texas there are no licensing requirements for pool builders so while I am using a reputable builder in the area, my impression is that there is a lot of room for f*ckery.

 

[DFWPoolNewb]

The plumbing should be sealed and pressurized with water. Once the plumbing is confirmed to be free of any leaks, then the gunite crew can come in and shoot the shells. The plumbing should remain pressurized during the shotcrete process and the pressure should be monitored before, during, and after the shell is complete. As long as the pressure holds, then the plumbing should be good.

Pool shells very rarely crack and when they do it’s usually due to significant ground movement or shrinkage of clay soil. As long as you soil condition was taken into account in the design, I think you will be ok.

Is burying PVC pipe “non optimal” … sure. Is it a catastrophic defect of the process that requires weeks of delay in reworking …. No. Builders do this all the time around here where I am and pool structures are generally long lasting. We have lots of old gunite pools with buried piping …

I wasn’t available to monitor when the plumbing company handled its part of the project so I have no real way of knowing whether they pressure tested. Frankly, not sure I would even know what that would look like.

I think gunite is supposed to happen Friday or Monday and I don’t have any idea if they plan to continuously monitor it throughout the process. It hasn’t been mentioned.

Is there a way for me to pressure test it myself so I can make sure they’re not feeding me a BS? Or to get some kind of “report” that the pressure test generated (not sure if this exists). Once gunite is done I seriously doubt they’ll be eager to bust out the shell if a defect is identified so they might be inclined to hide the ball.

 

[wireform]

Is there a way for me to pressure test it myself so I can make sure they’re not feeding me a BS?

Just look st the pipes by the pad location. Some should be capped or connected to other pipes with tee's or random parts. You should see a pressure gauge and some way to connect the system to pressurize it.

 

[DFWPoolNewb]

Just look st the pipes by the pad location. Some should be capped or connected to other pipes with tee's or random parts. You should see a pressure gauge and some way to connect the system to pressurize it.

I see that. But it doesn’t appear to be hooked into the power and I’m not sure how they would have actually tested it. sssiiiiggghhh. Thought I learned a lot before starting this process but apparently not enough. Didn’t even think to inquire about this.