Venting Question

[jadnashua]

Solids almost never make it to the sewer on the first flush. Each additional flow of water, whether from the shower, sink, or toilet flushing moves it further. The crucial things about the drain lines is that they must contain at least the minimum pitch, and as a result, no flat spots, dips, or back slope.

[seaofnames]

As for the
"You dont want too much pitch especially for toilets because the liquids will 'run' away from the solids leaving the solids to dry up and harden, causing a blockage in the pipe",

comment, it has been debunked by MANY testing lab and university studies.

I'd think worst case scenario for that...especially if its galvinized pipe which is quite rough after being corroded for years.

All plastic pipe would rarely/never have this problem, but there are dumb dumbs out there who think running drain lines at a weird angle is ok. Just not good looking either.

[dabensys]

I think that what your are rapidly discovering is that you are way in over your head. Licensed plumbers go through a 4 year apprentice program before standing for the journeyman license. You may indeed be a quick learner, but not that quick. That you have read the code is great but reading it and fully understanding it are two different things. Undertaking a project, without proper knowledge or funding can only lead to less than optimal results.

I agree with everything you say. In my line of work, software engineering, I have seen many occasions where someone reads a c++ for dummies book and then comes and applies for senior engineer position. I have to laugh (to myself) b/c these people really just don't get it. It takes years of practical experience to be able to correctly and efficiently write maintainable, high performing code. And every project is a little different.

I hate that I'm in the same boat as the 'c++ for dummies' guys w/r/t my plumbing knowledge, but this is where I am. I feel that it would be a personal failure on my part to have to call in a plumbing professional to help me do the layout, but that seems to be the concensus of what I should do in this thread. That said, I am still going to try and develop the dwv design myself and have the inspector review it before I start work. I hope you won't mind the occasional question from me between now and then.

Thanks for your time.

[dabensys]

In the end you will probably save money. I can't tell you how many times I have had to completely tear out all of the new plumbing that was improperly installed and re-do the job. Have a plumber do all the stuff that gets "covered up" and go ahead and install the fixtures and trim yourself. That is certainly within most folks skill level and will save a couple hundred bucks too.

Thanks! I appreciate your time and recommendations.