View Full Version : Question about adding a drain
02-19-2007, 08:26 PM
I am adding a drain for a wet bar in my basement. Is there a limit to how far you can run horizontal drain (as long as you have 1/4" per foot of slope)? What about the vent....does it have to go vertical for a specified distance before it can go horizontal? Are there limits to how far a vent can go horizontal? Thanks,
Oh yea, two more things. Is there a limit to how many times you can T off a 3/4" water supply line? I have stub outs for hot and cold and I would like to add a shower, two sinks, and a toilet. Is it OK to run one T off the sink 1/2" line for the toilet?
02-19-2007, 09:27 PM
Your water supply lines are pressurized...you can splice into them as many times as you want.
Yes there is a limit as to how far you can run a horizontal drain line even if you maintain correct slope...but you will have to check with local codes to determine what that limitation is.
The vent line can go in any direction you want so long as it's not a wet vent stack. If it is, then you have to maintain drainage principles until you get above the wet vent portion to the non-shared vent line (if that makes sense heh).
The vent line can go in any direction you want so long as it's not a wet vent stack. If it is, then you have to maintain drainage principles until you get above the wet vent portion to the non-shared vent line (if that makes sense
The vent cannot go in any direction he wishes, if it is going to be inspected. It should have a constant upward slope, JUST LIKE A DRAIN, but the fittings above the overflow level of the fixture do not have to be drainage pattern.
02-20-2007, 06:17 AM
Does anyone know what the typical limit is on how far you can run a horizontal drain? I want to add a sink that is about 30 feet from the existing 3" drain. I have plenty of slope to make the run, but I want everything inspected and correct.
02-20-2007, 06:42 AM
I see no problem with 30 feet of drain. I would use a 2", not a 1½ but I don't know if that is actually required.
The vent can't go horizontal until it is typically 42" above the floor level. If this sink is the only plumbing fixture in the basement, you will probably not find a vent, so will have to go vertically up to tie in to a vent stack on the upper level. If your house is not so old, some states for many years have been requiring the installation of a "future vent" in the basement, so you might get lucky.
02-20-2007, 08:24 AM
Thanks for the replies. I am adding a full bathroom also. My house was built with a bathroom rough in so I already have access to a drain and vent system. The wet bar will be in an adjacent room to the bathroom, but will be on the opposite end of the room (wouldn't want to make it too easy).
I obtained all my permits today and was able to speak to one of the inspectors about the sink drain. He said there is no problem with the drain as long as I keep the drop to 1/4" per foot. This forum is the best, thanks for all the help.