DWV Seepage...needs sealed or bigger issue?

[jsquared]

Hey there- I am looking to get some opinions/advice on an issue I have encountered with my DWV pipe where it meets slab in my garage. Backstory- I tore out some drywall in my garage a week or two ago after finding a small puddle of water that wouldn't go away and some mold on the drywall. I found a few issues after getting the drywall down. There was small consistent leak in the corner that after inspection appears to be some corroded copper tubing, then there was a more significant leak(which I think caused the actual puddle) that only occurs when the hot water in the master bath sink is run-nothing else so far replicates the amount of water that comes down other than hot water in that particular sink, and then there is this seepage at the base of the 3" DWV pipe. This last one is the most concerning to me because on the other two, while I still need to pinpoint the exact location of these leaks, I have at least been able to contain or isolate them so they are no longer causing any damage. However, with the DWV leak, I have not been able to determine if there is anything particular that causes the dampness or not. I do know though that if left unattended or checked, it seems the area would always have some dampness to it. I also know that both the master shower and guest bathtub drain down this pipe however just running them does not seem to cause a build up in moisture or anything...at least not instantaneously. Is this just a case where I need to seal the base where the pipe actually goes into the slab from normal ground moisture? Or is it an indication of a more significant issue? I do live in the Pacific Northwest so it is pretty rainy here especially this time of year. I have only been the house a little over a year so I am not super familiar with the inner working of the house yet. I have not seen any increase in my water bill and the water pressure appears to be good (70 psi based on hose bib gauge). I tried location a clean out to see about pressure testing that way but have not had any luck. Also I know that the house used to be on a septic however has been converted over to the sewer system. Any thoughts out there? I would really like to avoid calling a plumber if possible as I feel pretty confident I can fix the other two issues when I locate their source. Sorry for the long winded message, I just figured more information was better than less. I appreciate any thoughts and if there is any other information I can provided that will help let me know.

 

[FishScreener]

It looks like the water is seeping in from below the slab, following the dwv pipe, rather than leaking from it.

To check, get about six feet of paper towel, fold it length wise, wrap it around the dwv pipe about a foot above the slab, and put a run of duct tape around the bottom of toweling.

If the top of the towel gets wet it’s draining down from a leak above.

But fix the other leaks first, before you get too concerned about the water around the dwv pipe. It may be the low spot, and your other leaks may be the source of the puddle.

 

[jsquared]

Thanks!! I put that up this afternoon and will see what happens.

If moisture is seeping in from below the slab is that something to worry about or fairly normal and just need to seal it?

*After just an afternoon, I can confirm that it is coming from above. The paper towel is wet and the ground appears mostly dry. Thanks again!! Now to find the exact source of the leaks lol

 

[justin_dewan90]

Abs pipe is notorious in my area for fracturing. Leave the pipe exposed for an amount of time. If you get nothing but sunshine for an extended period of time and still have dampness, I'd imagine that abs is cracked. I'm going off my area, which is Kansas, we see abs fail more than it should. It doesn't stretch with the house and often shears off. If you are getting the moisture only when it rains. May need to be sealed better.

On another note, do you have a sump pump that has drain tiles connected to it in your basement?

 

[jsquared]

No, no sump pump. I actually don’t have a basement either. These are in my garage. Here in Washington it will be quite sometime for it’s not rainy lol but I will keep that in mind. I could see why the abs may not hold up well

 

[Rossando]

Run some fixtures that use that drain and have someone downstairs looking around and following the pipe run. I like to run hot water and follow the warmth.

 

[Rossando]

Might be a joint/fitting leaking. Get some dry towels and wipe them dry to make sure your on the right track. I’ve seen plenty of people miss a fitting when installing. Hopefully it’s somewhere reachable

 

[argile]

i don't agree. stop blaming the pipe. (it'd only leak if some nauxous chemical put a hole in pvc - i doubt it. pvc "glue" actually creates pvc so for it to leak ...)

it's not a pressurized PVC i assume, it's a drain if i see the size and guess usage right

if you have water under your foundation (ie, after rain) it will find a way up through the concrete (which is thinner in that area, and also perhaps not %100 bonded to the pvc)

you need french drains to direct rain water away from your foundation (it's actually code they do this kind of work minimally before they permit the final foundation)

that's my guess!

 

[Rossando]

i don't agree. stop blaming the pipe. (it'd only leak if some nauxous chemical put a hole in pvc - i doubt it. pvc "glue" actually creates pvc so for it to leak ...)

it's not a pressurized PVC i assume, it's a drain if i see the size and guess usage right

if you have water under your foundation (ie, after rain) it will find a way up through the concrete (which is thinner in that area, and also perhaps not %100 bonded to the pvc)

you need french drains to direct rain water away from your foundation (it's actually code they do this kind of work minimally before they permit the final foundation)

that's my guess!

There’s something going on there for sure, I think argile brings up a good point to look into as well.

 

[Geofd]

the 1st thing I would do would be to dye the 3 "stack and the 2" piping to the left.....just try one at a time maybe dye one then wait a couple of days then dye the other.....
as for you water is your meter spinning while things are at rest....is your boiler running more than it used to?????