Kitchen drain

[MaryBelle]

i have 2 Kitchen sinks by the exterior wall. Both of them has this loop
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Kitchen drain --- | .... |
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supposedly the loop is to help water drain, so it does not has trap air.
one kitchen sink has double bowl sink, that one drains well.
2nd kitchen sink has single bowl, and this one drain really slowly.

Question #1 :
is it because of the 2nd sink being single bowl, single drain, that's why this loop design is not releasing the air bubble trap and draining as well as the double sink model ?

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This system is in the interior wall, therefore the wall is packed with insulation. a week ago, i realize sink #2 is leaking into the crawlspace.
so i stop using the sink. My husband went to the crawlspace, and I run the water, no leaks, until I turn off the water, then water started coming down all over the edge of the subfloor.

Questions
#1. My husband is planning to rip out the granite counter top and the kitchen cabinet to check and dry the insulation. I am not looking forward to this mess. if this leak has happen, it happen only 2-3 weeks. right now, we have a huge construction fun blowing in the crawlspace to dry up the subfloor. the flooring is tile, and seems not damaged so far. My suggestion is to forget about that drain pipe, and just install a new drain pipe, goes directly down the kitchen cabinet straight down to the crawlspace.

Who is right here ? Me or husband ?

#2. Should I get it treated for mold ? no sign of mold yet but this is as far as the area visible in the crawlspace, since this happen so recently, and the house is just completed. we can not see what is happening behind the kitchen cabinet.

Thanks. Please post your opinion as soon as you can.

[Redwood]

MaryBelle,

and the house is just completed.

Are you saying this house is a newly constructed home?

[MaryBelle]

Is it a New House ?

Yes. Unfortunately, I am the general contractor. My mistake is hiring the lousy plumber. Either the loop system he installed is a bad idea, or he did not glue the joint properly. I am not planning to sue him. or have him back to fix the problem. As i may ended up with bigger problem and other problem i can not even imagine.

Otherwise, everything else seem to be fine. Because my husband watch him (the plumber) diligently when he was working on our house. But the one place that leak is unfortunately in the exterior wall, full of insulation, and covered behind the kitchen cabinet.

my proposal is cut thru the back panel of the cabinet, my husband proposal is remove the cabinet and counter top so he can make sure everything is dried up, which could potentially damage the granite counter.

who is right and/or wrong here ?

thanks.
Maribel