Pool Pipe Collapse near Skimmer

[HB1]

Hello For the 2nd time in about 5 years i have had a pool pipe ( 1.5" PVC) collapse near the skimmer basket. The 1st time I chalked it up to frost heave and differential soil settling. I live in the Toronto Ont area which has about 75 freeze thaw cycles per year. The existing pipe was backfilled with clay, topsoil, rock, debris. I repalced skimmer basket and backfilled with clean sand.

The pool is 12' x 24' and is heated by a solar heater on the roof of the house. There are 5 solar panels 5'x13' by which water is pumped up about 20-25'. by a 1 hp pump. Again the pipe collapsed ( about 30% capacity).

I now suspect the issue pertains to some suction problem causing the pipe to collapse.

Does any one have any thoughts or theories on why is occurring?

many thanks

 

[Texas Splash]

Welcome to TFP! To get the right people to your question, do you happen to have a pic of the PVC that collapsed? Also, please update your signature with all of your pool and equipment info which will help. See my signature as an example.

 

[JamesW]

Is it flex pipe or rigid PVC?

Are you keeping tabs in the skimmer with no water flow?

 

[JamesW]

Vinyl Pools, Pool Liners, Pool Service, Pool Renovations in Bucks County and Montgomery County | APCO Pools Specialties, Inc.

Apco Pools provides pool service and maintenance to clients throughout Bucks and Montgomery counties. We also have a broad inventory of pool liners, pool coping and other equipment.

www.apcopools.com

 

[JamesW]

If you use tabs in a skimmer, the water has to be continuously flowing or the concentration becomes very toxic and corrosive.

It is acidic and the chlorine level is about as high as it can possibly get.

 

[HB1]

Hello. Yes we for the most part keep 2 chlorine pucks in the skimmer. We also only run the pool for about 4-6 hrs a day.

Thanks for your suggestion. This is something that really never entered the realm of possibility in my mind . I have owned the pool about 35 years and have operated as such for the same, so would have thought if this was a potential flaw and cause of the problem, it would have manifested itself before now.

When I cut the pipe I will pay particular attention to this. Maybe if you would be so good I will forward you a picture of the inside of the pipe and you could comment on what you see.

thank you again. Much appreciate your input.

regards HB1

 

[JamesW]

Just post the picture here and we can see what it shows.

Is the plumbing flex PVC?

 

[HB1]

yes flex pvc

 

[JamesW]

yes flex pvc

OK, I think that it was definitely the tabs.

 

[HB1]

Picture of collapsed pipe

 

[JamesW]

As this chart shows, the minimum bend radius for 1.5" flex PVC is 5".

It looks like the bend radius is less than 5".

It is best to minimize the stress on the pipe going around a turn.

The bend radius combined with the tabs caused the pipe to weaken and fail at the point of maximum stress.

 

[JamesW]

View attachment 370382

 

[JoyfulNoise]

I know flex PVC use is very common in Canada but you would be better off getting rid of as much flex as possible and going with rigid SCH40 PVC. That 90 bend could be done with a sweep 90 degree fitting but you need to order the Sch 40 version as most hardware stores will only carry sweep 90’s in DWV pipe.

Flex is great if you’re pool builder installing a pool you’ll never have to maintain. Flex is terrible for the pool owner that has to live with the pool.

 

[JamesW]

I would make the minimum radius for any bends 8".

Anything tighter than that is overstressing the pipe.

 

[HB1]

thank you both for your insight and input. Much appreciated.

Unfortunately can't replace all of the flex pvc pipe as my entire back yard is stamped concrete with all piping underneath.

Will definitely use longer sweeping bend and eliminate use of chlorine pucks.

thanks again.