Kitchen drain line leaking in the crawl space.

Hi! Any ideas where to start? Under the kitchen sink is dry. There is a little bit of 'gunk' matter present under the area that is dripping.

Thank you for any help you can offer me

If I'm correct that the wet spot is the subfloor then I'd start where the sink drain goes into the wall inside the cabinet. You may have a cracked fitting, a bad solvent weld joint, etc. That is, if you are absolutely certain that nothing is leaking or was spilled inside the cabinet.

It's very clean under the sink. This and under the sink are the only two access points.

i would guess it is leaking inside the wall, at the tee, where the trap arm conects to the stack'

it is not the 90 in the picture. you can see wet floor ABOVE the 90. so the wet floor is below what ever it is

looks like you get to open the wall up.


i recomend, cutting out the back of the cabinet, do your fix. then cut some plywood to patch the back wall of cabinet

no sheet rock mud or painting to do.

Sounds like a plan. I just got some parts. I'll check back later with the outcome. Thank you for your feedback!

Update and fix to kitchen sink leak into the crawl space: As suggested, it was a T fitting that was leaking, and possibly never glued. Possibly knocked loose from the pressure of the dishwasher or the garbage disposal, or even snaking the drain line. The bummer was that I opened up the back of the cabinet before realizing that the leak was two feet over, behind the dishwasher. The hardest part of the job was removing old parts on the dishwasher to remove it.

As always, thanks for the input!