Floor Drains?

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shaken-n-stirred

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DIY NEW HOUSE CONSTRUCTON:

Open stud walls right now. Built on a nice crawlspace.

I wish to build some kind of a drain in the floor, or set myself up to be able to add such a drain later, for the purpose of a possible future water softener. (Softener would be on first floor over the crawlspace, so future drain work would be pretty easy .... venting not so much, but if required could be accounted for now)

Does such a drain need to be vented?
Does such a drain need to be built with a water line in order to keep the trap wet?

what else might I need to know about this idea per code.

Thanks
 
Drain for the WS discharge? you don't need a floor drain. is there a laundry drain nearby. the discharge can be go into the laundry stand pipe with an air gap connection. you can pre pipe the discharge in the wall if you want.

If you run it to a designated trap you can plug the trap until you connect the WS discharge but you will still need an air gap. you can not connect it directly to the or down into the trap.

I would not use a floor drain connected to the sanitary drain system. If the system got a stoppage it will come out of the lowest point being the floor drain. :eek: That makes a BIG MESS
 
Thank you so much for the reply. As a follow-up ....

First off, the SW would NOT be near the laundry. It would be in a utility room with a water heater and furnace.

A back up through the floor drain would not be NICE!. Would you recommend a 3 foot high stand-pipe in the wall like what is used for a washing machine?

Would the trap need to be plumbed so as to make it a wet trap (prevent evaporation of the trap). I would think not since a WS has frequent discharge so as to refill the trap.

Thanks again.
 
If it were me...

I would install a standpipe (code compliant as per washing machine standpipe) at the future location and cap it for the present. It has to be trapped and vented (ask advice of professionals here) to comply with code.

If the standpipe is to be located within the wall, there is a drain box available similar in appearance to a washing machine supply/drain box. An air gap fixture is available to connect the discharge hose to the standpipe.

You will need a power supply also (within code).

I have diagrams but they are on another computer.
 
Thank you for your detailed reply.

To be code compliant you need a vent, got it. In reality do you really need it? It seems to me there would never, ever, be a massive blast of water in that trap to flush it empty. You just have a slow trickle of water going into that trap.

I will likely run a vent, a pain in the but in this case, but just thought I would ask if it is needed (ignoring code).

thanks for the reminder about power, and wall boxes, and such.
 
2" floor drain must be vented. 3 and 4" do not require venting

WHAT?

what-the-hell-is-wrong-with-yo-82679.gif
 
To be code compliant you need a vent, got it. In reality do you really need it? It seems to me there would never, ever, be a massive blast of water in that trap to flush it empty. You just have a slow trickle of water going into that trap.

I will likely run a vent, a pain in the but in this case, but just thought I would ask if it is needed (ignoring code).

thanks for the reminder about power, and wall boxes, and such.

You need the vent. If difficult to vent to roof or tie into main vent, research AAV (Air Admittance Valve).

Personally, I haven't come across any reason to not be code compliant. They are there for a reason(s).
 
Thank you for your detailed reply.

To be code compliant you need a vent, got it. In reality do you really need it? It seems to me there would never, ever, be a massive blast of water in that trap to flush it empty. You just have a slow trickle of water going into that trap.

I will likely run a vent, a pain in the but in this case, but just thought I would ask if it is needed (ignoring code).

thanks for the reminder about power, and wall boxes, and such.


AHHHHHH. my little buddy.

let me help splain.

it is not ONLY the water leaving the fixture. it is also the water in the main

causing negative pressure.

say you have a toilet flush upstream from a lav.
and lav is not vented. the water running BY the combo for the lav,
CAN cause negative pressure on the trap
causing it to back siphon out.

see, drawing
.

120vac40a_rev.jpg
 

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