Whole House Drains and Vents

[jg2000]

Hello,

Been following this site for years, but this is my first post. I do a lot of remodelling work on my house but about a year back we finished fully re'doing the 2 upstairs bathrooms. I hired a plumber to redo all the drains/vents and I pretty much did everything else. Anyway now its really becoming obvious that there may be a problem. Both toilets upstairs and the one on the 1st floor get clogged almost a few times each week. At first I thought it might be my 4 teenage kids using too much TP or who knows what. Both toilets upstairs are brand new also. However now I just drew up this diagram and tried looking at things with new eyes and I don't think this is vented properly at all. I'm calculating about 18 fixture units upstairs and 8 more downstairs. The main stack is 3" cast iron from the street and goes up about halfway to the 2nd floor. At that point it was cut and everything above is all PVC with 1 main exit vent through the roof. What concerns me the most is the long (> 10 ft) horizontal run between the two vertical main stack sections. I know everything is pitched properly but I don't know enough to say is this really a problem and could it be contributing to my toilet issues. Also if it is, how bad is it and what might be the best way to fix it. I also included a graphic with some measurements. Any thoughts/suggestions? Thanks in advance,

John....

Top Down Measurements

 

[FullySprinklered]

If the drawing is accurate, then the venting is buggered up in several places. But I don't see how that would cause clogging in all three toilets. Other problems,yes.
Sometimes debris gets down the pipes during construction.

 

[Sponsor]

 

[hj]

NOTHING that caused the downstairs toilet to could have ANY EFFECT of the flushing of the upstairs one, and VENTING is very seldom a cause of poor draining, unless there is also a bigger problem downstream. However, if you drawing is accurate, it was a terrible installation, but still not a reason for all THREE toilets to not drain.

 

[jg2000]

Hey thank you both for the feedback. Few followup questions and clarifications. The downstairs toilet is old (20+ yrs) from the original owners and has always seemed to have had problems off and on. So I would treat it separately. However, the 2 upstairs units are brand new along with all the upstairs drains/vents. Those toilets I thought were suppose to be better then average performance. They are Toto Eco Soiree one piece units and paid quite a bit. So having them both installed on new pipes so far from the original cast iron line downstairs I would have thought there should not be an issue. Below is a picture during the construction phase showing the exposed drains for them and part of the upper venting. So just considering the upstairs is there anything could possibly inhibit proper drainage. HJ you mentioned that venting is rarely an issue, but if for some reason that upper vent got clogged at the roof or something could that cause problems? One of you also mentioned that in general that some of the venting was less then ideal. Could you elaborate? Wondering if there is anything I can do now to help. Also if the venting is not the issue, is there any chance that some blockage in the underground mains going out to the street could be a contributor? This is a 50+ year old house. Again, appreciate all the help. Thanks,

John....