View Full Version : Venting a 1/2 bath part II
MonsterMacMan
Oct 28, 2008, 09:10 AM
I've been dragging my feet on this job for fear of screwing up big time, sort of. My original question stands and I'll ask again with more details. The 1/2 bath I'm installing is off the kitchen. The toilet drain/sewer line is 36-44" from the main (cast iron) sewer line. This is the perpindicular measurement. 12-13' down the sewer line is a PVC tie-in into the cast iron. It appears to be vented up at the opposite end, roughly 14-15' from this tie-in. My question is twofold. First, would it be okay to come over the 36-44" and down the 12-13' and hook in to the 1 1/2 PVC that is currently cut into the cast iron. Second, if so, I want to make sure I have the proper rate of decent or angle of my sewer line. Oh, and a third... can I tee together the cold water for the sink with the cold water for the toilet? Ugh... I'd give a blueprint or pictures if I knew how. Thanks for all the help... M
massplumber2008
Oct 28, 2008, 09:19 AM
MMM...
If I understood you right... are you asking if you can connect a toilet into an 1.5" pipe that is connected to cast iron...?? If so, the answer is NO WAY!! Toilet requires a 3" pipe minimum.
Most likely, you will need to cut a 4"x3" wye fitting into the cast iron pipe (talk to us about this before you do it... ok? )... then you want to pipe PVC or ABS pipe so the toilet gets 3" pipe....connect a 3x2 wye about 3 feet from toilet elbow and run to the sink. Connect this 2" pipe to sink (by 2 x 1.5" sanitary tee fitting) and then run the 2" until you can connect it into a 2" vent or larger in attic (or could penetrate roof by itself).
You CAN connect the cold water from toilet top cold water for sink...;)
3" pipes and smaller PITCH at 1/4" per foot... and you hang pipes every 4 feet.
If I misunderstood, please let me know. I'll be back tonight about 7:00 (off to work again... just stopped in for lunch!).
MonsterMacMan
Oct 28, 2008, 09:39 AM
okay... currently I have the toilet installed/attached to the floor with 4" coming out...I have the 4"x3" wye fitting ready to go with the 3" piping. I have never cut into cast iron which is what I will need assistance or advice on. Added to this is where along this cast iron should I cut in? I'm on 36-44" away. Won't this give me a problem with pitch? With the venting, if I'm tied into this cast iron, won't the venting of this cast iron(the original venting) be enough? If not I'm in for a helluva job...lol...again, I have 3" PVC ready to go... unless I should just run the 4" the roughly 36" to the cast iron and drop in the 4"x3" wye. I understand now about connect the toilet and sink with the 3"x2" wye and then running the 2" after the 2'x1.5" sanitary tee on to the 2" vent or separately to the roof...only problem I see here is you said 3' from toilet elbow and that about puts me over the cast iron (original sewer line)...unless this is okay and I can bring the 2" back to the sink (might only have space issues with that then)... have I thoroughly confused you yet... sorry... thanks for the quick response... will wait till tonight to check back... thanks
massplumber2008
Oct 28, 2008, 07:04 PM
Hi MMM...
Let's see if I can confuse the both of us... ;) If I get you.. you need to cut into the cast iron pipe with a 4"x 3" wye fitting.. right (no tee fittings allowed on horizontal drainage so wye fitting is correct choice here)?
Best overall would be to connect a 4" x 3" No-Hub cast iron wye fitting into the cast iron main drain and connect together using 2-4" 4-band clamps as in my picture below (the fitting and the clamp are probably only available at a local plumbing supply company... ;) ).
To install this fitting into the cast iron you will probably be best to use a sawzall/reciprocating saw with a carbide/grit or diamond sawzall blade (diamond sawzall blade is tough to find... around$15.00 and worth it if you can find it... made by Lennox, carbide/grit sawzall baldes are available at home depot).
Support the cast iron pipe as you make your cuts... use bricks, etc. as there is good amount of weight here. Be very careful here.. people have gotten hurt cutting into cast iron when not properly supported!
You could also rent a ratchet cutter or a snap cutter here... but since you only have 2 cuts and these tools can cruch cast iron pipe as much as they can cut cast iron pipe... I recommend that you stick with the sawzall so this doesn't grow into larger project for you... :)
You want to measure the cast iron wye fitting... add about 5/8" or so to measure and lay this measue out on pipe... then cut that length out of the 4" cast iron pipe...you need the extra 5/8" or so to allow for the NOT SO STRAIGHT CUTS... plus the thickness of rubber sleeve rib (see inside clamp).
You need to have a wet vent at a minimum... regardless of how many vents are present. Without getting into too much... run the 2" vent as described and confirmed by you..this is wet venting. Some codes want individual vents for each fixture...let me know if want to discuss this further...
You said, "only problem I see here is you said 3' from toilet elbow and that about puts me over the cast iron (original sewer line)... unless this is okay and I can bring the 2" back to the sink (might only have space issues with that then)"... YUP!! That confused me a bit... let me know what you mean here...
THANKS...
MARK
MonsterMacMan
Oct 30, 2008, 07:09 AM
Last thing on the toilet... I have 4" coming directly from toilet straight down to elbow(4"x3")...I'm gonna run the 3" to cast iron main drain... cutting in with sawzall using 4"x3" No Hub Cast Iron Fitting... one thing you said I'm not sure about "You want to measure the cast iron wye fitting"... is this the 4"x3" No Hub..?
Gotcha on the wet venting... only possible issue here is that if the vent pipe isn't steel then it is cast iron... it is so deeply buried behind stuff that I can barely get in there... but it does run directly off one end of the Cast Iron main drain...
MonsterMacMan
Oct 30, 2008, 07:10 AM
Guess I have to "spread the reputation around"... not sure what that means... telling others of you? Or rating others... but I think you are awesome for helping others with your expertise... I greatly appreciate it...
massplumber2008
Oct 30, 2008, 09:45 AM
Yup...
Measure the length of the 4x3 wye fitting and then add a 1/2" to measure. This combined measurement is what you want to cut out of the cast iron main line. The extra 1/2" acommodates the thickness of the rib that is part of the rubber sleeve of each clamp (and gives you a little bit of room to accommodate a slightly crooked cut... ;) ).
Let me know if need more. I enjoy helping when I can!
MARK
MonsterMacMan
Oct 31, 2008, 05:20 AM
Thanks... let you know when I get the job done... or if I run into trouble I know I can count on you or this site... everyone here is excellent... peace...