Waster discharge pipe size ? - Plumbers say tear up my new slab to up size risers

[kenmac]

Nothing else to the story. Builder dropped that news on me Saturday. I plan on talking to the new plumber directly to understand his concern better. So far, I think 3" is fine based on the opinions so far. Builder only said he thought the plumber was concerned with flushing. Thanks for the insight guys.

you might want to check his credentials .. The new guy may not be certified. (provided your state requires plumbers to be certified) If there are no inspections. he could get by without being certified

 

[Cataclysm]

Seems like now that the builder may have actually FIRED THE WRONG PLUMBER?
3" is fine!

I'm thinkin the same thing about the plumbers. Leave that 3" and hit that lever with confidence!

I would be checking the new plumbers work every single day with a level in hand. The builder is in it to make money. They will use the lowest bidder generally. We get called way to often to fix the budget plumbers money saving short cuts.

 

[bigdeano]

I built a house with 3" and never had a clog in the 5 years I lived in it.

 

[turnkey4099]

I have a 4" main line running the entire 60' length of the house with a 3" riser on each end of the run. Worked fine for 35+ years. If you have a 3" riser to each toilet - that's more than adequate.

Have you checked with the building inspector? There should be specifications for the required riser pipe to meet code.

 

[CurlyDave]

I put 3" in my house in CA and lived in it for 20+ years with no problems.

A modern low-flow toilet uses 1.6 liters/flush. That is a slug of water 14" long in a 3" pipe.

Get a different plumber...

 

[cat fever]

As at least two other plumbers have said and I will also say, you are fine. I have plumbed literally thousands of new homes. There is nothing wrong with what you have stated. It also would not matter with high or low flow toilets, you will have no problems. Below was a quick search for fixture units and line size. As you can see 3" is OK by the "Uniform Plumbing Code."


Search Results
DFU are used to determine the drainage from fixtures and required capacity of sewer service systems
Individual Appliance, Appurtenance or Fixture Minimum Size Drainage Fixture Unit Values (DFU)
(inch) Private Installations
Bar sink 1 1/2" 1
Bathroom (water closet, lavatory, bidet and tub or shower) 3" 6
Bathtub 1 1/2" 2

 

[kidr]

Some would argue that you get an even better flush with 3'' pipe.

 

[Larry Caldwell]

One big mistake amateurs make is to oversize drain lines on the theory that they will work better. Just the opposite is true. A drain that is too large will not scour and is prone to clogs. You want to keep the water velocity fast enough to carry the solids out. Stick with 3", and also use the smallest drains allowed for lavs. Inch and a quarter will be much more reliable than two inch for a sink drain.

 

[TCJatko]

New house, 3" riser to 4" mains, no problems.

 

[Egon]

What are your local code requirements? That is the criteria that must be met.

 

[newbury]

Make sure everybody eats a lot of prunes, that should keep stuff flowing.

 

[kenmac]

This is the one time I wish there was an inspection. We are in the country so no inspections.

Some of you keep telling him to check with inspections

 

[nybirdman]

All toilets are 3" discharge,3" riser to a 4" main is fine.Your "new" plumber is dead wrong.Make sure you have adequate venting.

 

[Gary Fowler]

All toilets are 3" discharge,3" riser to a 4" main is fine.Your "new" plumber is dead wrong.Make sure you have adequate venting.

That is what is in my house that was built 6 years ago and everything works fine. I am not even sure that a 4" riser hub would fit the toilet bowl bolts!!

 

[JRobyn]

Some of you keep telling him to check with inspections

Or "go with the code requirement" which are non-existent in his area.

Sad how people will post in a thread without reading it.

 

[PILOON]

20 years with 3" here (4" from house to septic) with no problems and I'm equipped low flush.
Heck one house even had RV toilets that are VERY VERY low flush. (and 22 years B4 pumping the tank)

 

[oosik]

Whoa, right there, tall dark stranger. I live way out in the country - there are no plumbing inspections out here, but we sure do have a state plumbing code. When I lived in Alaska there were only plumbing inspections within the designated municipalities(counties) but there was still a state wide plumbing code that applied everywhere.

 

[Sysop]

Some of you keep telling him to check with inspections

Just because he lives outside of where inspections occur, does not mean the code officials are clueless as to what works and what doesn't in their area.

I personally would be shocked if there are any issues from 3" off the thrones to a 4" main. It's how many are done here and have been so for many years. Very seldom are there issues and those issues are never resulting from the 3" off the toilets.

 

[kenmac]

Just because he lives outside of where inspections occur, does not mean the code officials are clueless as to what works and what doesn't in their area.

Don't know what you mean by this. He has said there are no inspections in his area.
If there are no inspections in his area, why would there be any code officials ?

Inspections or not. Most places are now using international plumbing codes. There may be some still using state code, but most are following international codes for plumbing , gas, mechanical, building, fire

Are plumbers in his state required to pass a state exam and be certified before performing any plumbing work ? I have no clue. If they do, the plumber should have a card with a state certification number.

Here, we have a state plumbing board that governs all plumbers. If you have a problem,and the plumber doesn't try to resolve the issues. You contact the plumbing board

 

[Sysop]

What I mean is: just because he is rural and inspections do not take place at his location, that doesn't mean the code officials in the most local city to him are not familiar with the way such things are done in that general area. Just because he can't have an inspector come look at his site doesn't mean he can't visit (or call) them and pose a rather simple and straight forward question.