Minimum pressure test for drain lines ?

I will have some 4" main drain lines with other pipes connected to it for sinks, etc...and these drain lines will later be covered with concrete. I understand that these are drain lines and not under any pressure but my concern is any sewer leaking under the slab over time. There will be a vapor barrier but still concerned.
When interviewing different plumbers for this job then what is the minimum answer I should expect from them to do as far as testing the pipes when they are done to make sure there are no leaks and maybe some tips on how they say theyre going to go about it ?

cap the ends, extend 1 risor up 10 ft and fill it with water. bleed the air out where possible.

Thanks for the help. I will see if this is one of the testing procedures of the plumber I want to use.

plumber

What is the plumber doing? A test would be the normal process after they are installed. Did you install the pipes and now want a plumber to test them?

The plumber would be installing 4" drain lines and also connecting the correct sizes of pipes for fixtures (sinks/showers/vents) to the 4" lines. These are drain pipes for under a concrete slab. Again Im wanting to know different methods of how the plumber might test the pipes after they are laid. Anything I might need to look out for after the job is complete.

test

The plumber will use whatever test the inspector requires. Usually, and easiest is a 10' head water test. But a 5 psi air test is also adequate, but sometimes more difficult to achieve and harder to find any leaks.

Sounds great HJ. I guess if the head water test is used then it sits with water for some period of time and then emptied and then is the pipe lifted to see if there is wet spots ?

test

Once the pipe is put in place it is NOT disturbed. You put water into the pipe and see if it stays there. If it does there is no leak. If it doesn't THEN you look everywhere to find the leak. It is easier to find with water than with air, because you can see the wet spot.

Good deal thanks.
Sounds like the water test is best and I will make sure thats the test the plumbers says they will perform. I was asking about lifting it up because I thought it might be possible to be leaking on the bottom side of the pipe and draining through the pea gravel below that the pipe would be sitting on but Im thinking now as Im typing this response that paper towels or something similar might be set up under where there will be joints for such leaks...right ?

Yes, putting paper towels under the joints and then lifting the pipe out of the ditch is the approved method.

Sounds great. I will be meeting with the first plumber tomorrow and it will be interesting to see what he says.
Thanks again for all the help.

kordts said:

Yes, putting paper towels under the joints and then lifting the pipe out of the ditch is the approved method.

Click to expand...

using this method wastes a lot of paper towels. my uniform service provides rags that are re-usable and don't diminish the rain forests.

Thanks again for all the help. I really enjoyed my conversation with the plumber I had earlier today. He said that he does indeed perform the head pressure test. He also said most all leaks that might be on the bottom of the pipe will be minimum at best or will show with either a wet spot or a substantial loss of water in the pipe as was mwntioned on here earlier. He also explained that if there was a small leak that first of all I will have a vapor barrier installed and also that in normal operating conditions that the pipes dont have that type of constant head pressure as it does in the test all the time and that the leak if there was a small one would drip very little if not get clogged up in time and virtually stop from intermediate flushing of toilet water etc...He said he would make sure that its done right the first time. He also mentioned he would use 2" pipe for fixtures rather than 1-1/2 and I liked hearing that. I also believe he has me talked into getting PEX supply lines ran under the slab rather than going through the walls or overhead. Time will tell and he said he would return a quote to me a few days.

pipe

Here, BEFORE the inspector will even look at the pipe, it has to be backfilled to a point above the centerline and the fill worked under the pipe. IF you lift the pipe to look for leaks that dirt/fill is going to fall underneath it and that will COMPLETELY destroy the original grading of the pipe, making complete excavation and relaying necessary. YOU DO NOT DISTURB THE PIPE once it is in place. If you have a leak and suspect it it at the bottom of a joint, you dig around THAT joint and check it.

Yes sir hj. I believe that was his exact intentions in procedure from our conversation as well but I could be wrong. In other words I think he was saying the same as you have been and that he will find the leak without moving the pipe but intends on there not being a leak to start with. I will be meeting with another plumber tomorrow but I have a feeling right now that this one I met today will be the one I use.

The running the hot and cold water lines is easier than installing the drains and vents. You can snake these lines around to fit just about anywhere. However, it’s tricky to solder copper joints in tight spots.