Can I tap the house waste line cap?

[Biff0rz]

I don't have a drain in my fish room which is in the basement. I have one in the utility room but I tapped the drain there with a 1/4" fitting for an awc & rodi waste drain. I want to run a waste line for a skimmer skimmate drain but in 3/8" size. I'd also like to reduce the run length in case I need to maintain it. In the fish room (opposite side of room) I have a 4" house waste drain, before it goes into the cement floor there is a wye. Can I tap the cap of the wye and place the drain line in there without any sewer type of issues? I want to tap the cap in case I ever move (or whatever), then I can just replace the cap and go.

 

[Idoc]

I don't have a drain in my fish room which is in the basement. I have one in the utility room but I tapped the drain there with a 1/4" fitting for an awc & rodi waste drain. I want to run a waste line for a skimmer skimmate drain but in 3/8" size. I'd also like to reduce the run length in case I need to maintain it. In the fish room (opposite side of room) I have a 4" house waste drain, before it goes into the cement floor there is a wye. Can I tap the cap of the wye and place the drain line in there without any sewer type of issues? I want to tap the cap in case I ever move (or whatever), then I can just replace the cap and go.

I'm interested in hearing from some plumbers on R2R about this as well. I've been thinking of doing the exact same thing!

 

[Diet Coke]

I don't have a drain in my fish room which is in the basement. I have one in the utility room but I tapped the drain there with a 1/4" fitting for an awc & rodi waste drain. I want to run a waste line for a skimmer skimmate drain but in 3/8" size. I'd also like to reduce the run length in case I need to maintain it. In the fish room (opposite side of room) I have a 4" house waste drain, before it goes into the cement floor there is a wye. Can I tap the cap of the wye and place the drain line in there without any sewer type of issues? I want to tap the cap in case I ever move (or whatever), then I can just replace the cap and go.

You really should not tap directly into waste pipe
A trap with an air gap between the pipe and the drain is needed to keep the suction from siphoning and also to keep sewer gases from being released into the line

 

[Diet Coke]

You really should not tap directly into waste pipe
A trap with an air gap between the pipe and the drain is needed to keep the suction from siphoning and also to keep sewer gases from being released into the line

I’m not a plumber but I am a general contractor

 

[ca1ore]

It probably violates a bunch of plumbing codes ... but I have done it. Just build a water ‘trap’ into your 3/8” tubing.

 

[Gablami]

I’ve also done it, twice. Tapped a 1” male thread into my clean out drain (post #31 on my build thread). On my previous build I tapped a 1/4 John guest adapter into the drain for a continuous AWC.

 

[IanK]

If the cap is plastic, go ahead. If the cap is brass that's been screwed into cast iron for a long time it will be very difficult to change if you were to move. I am a plumber

 

[IanK]

Also, not code but it's ok, It's your house.

 

[Waters]

As everyone stated, it is against code but it doesn't harm anything.....according to my plumber. Mine has a plastic screw cap that I unscrew and pump water change water out of and then just cap it back up.

 

[DaneGer21]

I’ve done it. I drilled and tapped my lid. I taped and then screwed in a 1/4” JG check valve, then connected the waste line

 

[Biff0rz]

Thanks everyone, sounds like it'll work out OK! It's a plastic cap. Attached a pic.

 

[Biff0rz]

If the cap is plastic, go ahead. If the cap is brass that's been screwed into cast iron for a long time it will be very difficult to change if you were to move. I am a plumber

Do you suggest having a 'trap' made with the line or will straight in with a check valve suffice?

 

[DaneGer21]

If the cap is brass that's been screwed into cast iron for a long time it will be very difficult to change if you were to move. I am a plumber

I actually had to do this when I sold my home 2yrs ago. The inspector noted the alteration, and the new owners wanted me to “fix” it. Mine was old, metal on metal, and it did suck to break loose. I actually broke the top “square” off before it came loose. IF I recall it came out in a few pieces and not as one haha. I don’t know what code states but when I put the new brass one in, I used anti-seize on the threads.

 

[DaneGer21]

Do you suggest having a 'trap' made with the line or will straight in with a check valve suffice?

To be honest I’m not 100% sure, but to me, if your fitting is sealed to the cap, and all lines are connected, there is no where for the “gases” to go except up and out like normal. It’s not like you are just venting into the house. Plus, the larger diameter piping will be less of a restriction anyways for the gases to continue to flow upward.

But, for the price of RO tubing, which is minimal, you could surely add a downward loop for cheap.

 

[IanK]

I would put a trap on it with the hose

 

[Biff0rz]

I would put a trap on it with the hose

Ok, thanks. So basically a horizontal S curve.

 

[Memisis]

You would want to tap above the main floor toilets by a few inches. If they overflow you have bigger issues not caused by your tap. And yes have a trap with a vent cap on top. I've been thinking about this lately as well.

If you didn't need to use it often you could get away with a screw cap and put the line in there. However with sewage being just generally in there I'm hesitant to risk some freak exposure to tank water.

Great question!

 

[Biff0rz]

You would want to tap above the main floor toilets by a few inches. If they overflow you have bigger issues not caused by your tap. And yes have a trap with a vent cap on top. I've been thinking about this lately as well.

If you didn't need to use it often you could get away with a screw cap and put the line in there. However with sewage being just generally in there I'm hesitant to risk some freak exposure to tank water.

Great question!

This is in the basement, so I'd have two floors of toilets above..