Trenching water lines pex vs. poly vs.soil with no rock vs. lots of rocks

[lennyzx11]

I am in the middle of mine. A run out to a future shop/cabin in the yard. About 120 ft. I have the trench done and since I was laying electricity also. I set two runs of 2" schedule 40 pvc conduit with one for the water 12" apart.
Still in the research phase on running pex or black poly. I have to cut my main supply black 1" poly to tie in with a tee off but can't find one ( Tee) at the big box stores. Going to a plumbing supply and my local rural water dept Monday .

 

[jenkinsph]

Well it was done, 18" deep. No sleeves. The excavator was going to go 12" deep. My soil for the entire run was virtually stone free.


When in Fulton do what the Fultons do - The excavator and plumber said no sleeve needed, they just ran 3/4 PEX. They wanted to run about 400' of 20' PVC but I DID NOT WANT JOINTS. They agreed to PEX but complained about the cost difference. /edit because the material cost more

I get tired doing all the research then find the locals believe in other reality's. Based on info garnered on TBN I first asked to use 200psi black poly well pipe, they claimed nobody used that and they didn't want to put it in because it would leak.

I think you will find the friction loss on 400 feet of 3/4 inch pex tubing will reduce the flow too much. For a run of that length the PVC 40 1 1/ 4 inch would have been more appropriate. And any plumber should have known that.

Most of the pex tubing without expensive jackets is rated for 100 psi. The 3/4" pex tubing (cts) will handle a flow of 5 gallons/minute with slightly less than 24 psi pressure loss in 400 ft. run. At 10 gallons/minute the pressure loss would be about 84 psi in 400 ft. That is probably more than the source pressure so you could not reach that flow level. I am paying about .59 cents/ft. for pex and have used lots of it for piping in homes.

Most residential wells use 1 1/4" pipe size whether pvc schedule 40 or the 200 psi poly pipe you mention. This would handle a flow of 10 gallons / minute with slightly less than 3 psi pressure loss in a 400 ft. run. This schedule 40 1 1/4" pipe is costing me .27 cents/ft, less than half the cost of the 3/4" pex.

So the cost of materials were to high and the cost of pumping in continuum will be much higher. Time to fill a water trough or spray tank will be longer too. I recommend you hire a better plumber next time. I am a master plumber and don't usually say too much but this guy did not do you any favors.

 

[jimmysisson]

If you do dig a trench, take the time to walk the tubing into it and jam it into the corner of the ditch. Better protected from rocks than if lying in the center. If you have rocks, that is.
Jim

 

[Raspy]

I think you will find the friction loss on 400 feet of 3/4 inch pex tubing will reduce the flow too much. For a run of that length the PVC 40 1 1/ 4 inch would have been more appropriate. And any plumber should have known that.

Most of the pex tubing without expensive jackets is rated for 100 psi. The 3/4" pex tubing (cts) will handle a flow of 5 gallons/minute with slightly less than 24 psi pressure loss in 400 ft. run. At 10 gallons/minute the pressure loss would be about 84 psi in 400 ft. That is probably more than the source pressure so you could not reach that flow level. I am paying about .59 cents/ft. for pex and have used lots of it for piping in homes.

Most residential wells use 1 1/4" pipe size whether pvc schedule 40 or the 200 psi poly pipe you mention. This would handle a flow of 10 gallons / minute with slightly less than 3 psi pressure loss in a 400 ft. run. This schedule 40 1 1/4" pipe is costing me .27 cents/ft, less than half the cost of the 3/4" pex.

So the cost of materials were to high and the cost of pumping in continuum will be much higher. Time to fill a water trough or spray tank will be longer too. I recommend you hire a better plumber next time. I am a master plumber and don't usually say too much but this guy did not do you any favors.

Great post with real information.

Also, PEX must be protected from the sun, so it has to be sleeved where it enters and leaves the trench. It will also freeze easier in the smaller diameter, if that is an issue.

So, PVC is the more practical choice, for pressure drop, UV resistance and cost. Poly might be the absolute longest lasting since it is even less affected by UV than PVC and it won't crack from impact. I ran poly lines outside at my place. The only "leaking" issue with poly might be the use of barbed fittings, which are very hard to push into the thick walled poly piping, and cheap band clamps. There are better fittings made of brass and stainless that will not leak and are easy to use.

 

[newbury]

I think you will find the friction loss on 400 feet of 3/4 inch pex tubing will reduce the flow too much. For a run of that length the PVC 40 1 1/ 4 inch would have been more appropriate. And any plumber should have known that.

Most of the pex tubing without expensive jackets is rated for 100 psi. The 3/4" pex tubing (cts) will handle a flow of 5 gallons/minute with slightly less than 24 psi pressure loss in 400 ft. run. At 10 gallons/minute the pressure loss would be about 84 psi in 400 ft. That is probably more than the source pressure so you could not reach that flow level. I am paying about .59 cents/ft. for pex and have used lots of it for piping in homes.

Most residential wells use 1 1/4" pipe size whether pvc schedule 40 or the 200 psi poly pipe you mention. This would handle a flow of 10 gallons / minute with slightly less than 3 psi pressure loss in a 400 ft. run. This schedule 40 1 1/4" pipe is costing me .27 cents/ft, less than half the cost of the 3/4" pex.

So the cost of materials were to high and the cost of pumping in continuum will be much higher. Time to fill a water trough or spray tank will be longer too. I recommend you hire a better plumber next time. I am a master plumber and don't usually say too much but this guy did not do you any favors.

You may be confused, this is coming from the county waterline, not a well.

As the plumber explained to me the previous line was 3/4 and the connection to the meter at the water main is 3/4, apparently that's what they use around here.
The one way run was not 400', that included a tee off for the apartment and the sheds, which use very little water. We've been running for about 4 days now and notice no difference in water pressure from before. The PEX they used is rated for 160 PSI at 73 degrees. The biggest thing we routinely fill is either a bathtub or the washing machine. I'm not to concerned about the cost to the county for

pumping in continuum

Yes the cost of materials was higher compared to PVC, but I'm a worry wart and I didn't want to worry about leaking joints. My aching joints are enough to worry about. Also I think it would have taken a lot longer to lay and join the 20' sticks, thus more labor.

 

[jenkinsph]

You may be confused, this is coming from the county waterline, not a well.

As the plumber explained to me the previous line was 3/4 and the connection to the meter at the water main is 3/4, apparently that's what they use around here.
The one way run was not 400', that included a tee off for the apartment and the sheds, which use very little water. We've been running for about 4 days now and notice no difference in water pressure from before. The PEX they used is rated for 160 PSI at 73 degrees. The biggest thing we routinely fill is either a bathtub or the washing machine. I'm not to concerned about the cost to the county for
Yes the cost of materials was higher compared to PVC, but I'm a worry wart and I didn't want to worry about leaking joints. My aching joints are enough to worry about. Also I think it would have taken a lot longer to lay and join the 20' sticks, thus more labor.

Well I reread the thread prior to posting above and there was no mention of usage, tee in lines or water source in your prior posts. So I assumed you were replacing a 400 ft. water line from source to termination end. Not a matter of confusion as much as not enough information.

That said above the cost of materials for installing the larger line would be minimal and you would have had much higher water flow when needed. Depending on where the line tee's off and where the primary use was I would have used at least 1 inch for the longest run. The job is over with and if you are satisfied with the results that is all that matters.

 

[jenkinsph]

Great post with real information.

Also, PEX must be protected from the sun, so it has to be sleeved where it enters and leaves the trench. It will also freeze easier in the smaller diameter, if that is an issue.

So, PVC is the more practical choice, for pressure drop, UV resistance and cost. Poly might be the absolute longest lasting since it is even less affected by UV than PVC and it won't crack from impact. I ran poly lines outside at my place. The only "leaking" issue with poly might be the use of barbed fittings, which are very hard to push into the thick walled poly piping, and cheap band clamps. There are better fittings made of brass and stainless that will not leak and are easy to use.

Both PVC and PEX should be protected from sunlight and uv exposure. I use Mueller Streamline push on fittings for poly ips lines utility grade. I never use the barbed fittings and hose clamps because I have to warranty my workmanship. Poly in cts tubing sizes can work well with pex fittings at a lower cost particularly good for the smaller common 3/4 and 1 inch sizes. The plastic pex fittings are better in most cases than brass as the plastic fittings are corrosion resistant.

All of the materials are very good today if used properly and buried deep enough to limit expansion and contraction.

 

[muddstopper]

Recently had, "city water" ran to MIL house. Old well was a 35ft deep handdug well. The water department used a meter with 3/4 connection, I wanted 1in but they wanted a extra $1000 for the connections. Doesnt make sense, but that is how it is. I needed 340ft of pipe and had 180ft of 1in sch80 pvc well pipe. My first thoughts was to use the 1in pipe for the first 180ft to save a little money. I would have had to adapt from 3/4 to one inch and then back down to 3/4. What I found was the couplings for the 1in sch 80 pipe cost more than a 20ft stick of bell 3/4 pipe. So I ran the entire length with the smaller pipe. Once installed to the house, I had to put in a pressure reducing valve to keep from having to much pressure at the faucets. I think the main line pressure was something like 80-90psi. Anyways, I own a trencher so I trenched the lines 24in deep and it was all red clay with little rocks, so I figure the lines will out last her.

 

[Raspy]

jenk,

Not sure what kind of plastic fittings you are referring to with PEX. There are a number of plastic styles for PEX, but I never use them. Because, as you say, "I have to warrantee my work", and I've seen them fail.

It's strictly either brass with copper crimp or brass with stainless pinch rings. Never had a failure with these and I've used a lot of them.

I'm gonna look into using PEX fittings with poly.

 

[jenkinsph]

jenk,

Not sure what kind of plastic fittings you are referring to with PEX. There are a number of plastic styles for PEX, but I never use them. Because, as you say, "I have to warrantee my work", and I've seen them fail.

It's strictly either brass with copper crimp or brass with stainless pinch rings. Never had a failure with these and I've used a lot of them.

I'm gonna look into using PEX fittings with poly.

It depends on the water in your locale, we started using pex about 20 years ago here. Best thing since sliced bread, all brass fittings no apparent problems, that continued for many years. But in the past 6 years we have had to replace lots of these brass fittings that were being eaten up from the inside out. Not something most of the plumbers in our area were expecting to happen. In MS with softer water I would expect the brass fittings to last forever.

If you look into the poly the cts sizes have the same dimensions od and id as pex tubing sizes. This will not work with pipe ips sizes but in large markets both should be available. This should reduce the cost of lines since poly is less expensive than pex.