New Shower

[HayZee518]

Lazypup - I'm in NY. Five years ago I replumbed my entire house drain system main line and the branches. I re-did all my domestic hot and cold water lines and got the whole installation approved by the inspector.

[LazyPup]

I am very glad to hear that. I would be one of the first to agree that the Plumbing industry as a whole needs to make some sweeping changes, but restricting the homeowners ability to perform service on their own home is not and can not be a viable answer to our problems.

The greatest single problem in the Plumbing trade is the lack of a standardized National Plumbing Code. As I am sure Hayzee can confirm, in the electrical trade they have a National Code. Local jurisdictions often then ammend that code to develope a regional or municipal code. But even then, they dont ammend the code, but rather just define which option they want to see in those instances where the National Code allows variations.

By contrast, in the plumbing trade we have a code nightmare. Primarily we have the Uniform Plumbing Code, International Residential Code or the BOCA code, but in the southeastern states they often use the SBCCA code. California has an entirely different Code.

As if that were not problamatic enough, many municipalities do not even stay current with the code they have agreed to adopt. By Example, in Eastern Ohio most communities use the BOCA code, however Youngstown is using the 2002 BOCA Code while its neigboring community of Brookfield still uses the 1994 BOCA Code.

In many parts of western Pennsylvania its anybodies guess what code to use. To make matters worse, there is no permitting or inspections required on residential work except new construction, or in the case of rehabing a structure that has been vacant more than 3 yrs.

In Sharon,Pa. I recently called for an inspection and a firetruck showed up. They informed me that the fire department was doing the inspections. A young rookie fireman came into the house, checked to make sure the bedroom windows would open, checked the smoke alarms and checked to insure that the water heater flue pipe was properly sealed to the chimney, then signed off my plumbing inspection, go figure.

By contrast, while working in Florida, we not only had to have everything permitted, in order to replumb a house we had to have 5 inspections, Sewer or septic field, rough in, stackout, potable water supply and water heater installation.

As if codes and permitting we not enough of a nightmare, there is absolutely no standards on licensing of plumbers. In Florida where I took my apprenticeship we were required to be employed under the supervision of a Master Plumber for a minimum of 40 hours a week for four years. If you didnt work a full 40 hours that week didnt count. In addition, we had to attend a state approved night school course for the entire four yrs, and we had to submit weekly timesheet reports to the state department of labor. At the end of the four years, if we had completed the required academics, had a certificate of achievenment from the department of labor, and had a written letter of recommendation from the Master, we could then sit for the state licensing exam.

Here in Ohio and Pennsylvania if one desires to be a residential plumber you simply go to city hall, show proof of workmans comp insurance (if you employ 4 or more people), show liability insurance, and pay an annual fee ranging from $85 to $150 per community. In many rural communities there are no requirements whatsoever.

[techguy]

It sounds like it's just a free-for-all amoung the states. LazyPup, I dug up the lines (broke up concrete) this past weekend and I am ready to go for next weekend. I do, however, have another question. The house trap is cast iron. It looks like the house line and the street line are connected witth a rubber bushing, not lead. Does that mean that friction is the only thing holding it together? Can the joint be pulled apart without cutting the pipe?

[LazyPup]

Yes,,if it has a rubber bushing it is just a friction fit and you can pull it apart.

[kactuskid]

Lazy Pup, I wanted to thank you for such an interesting read you provided concerning DWV systems. I learned alot from this and have a question regarding some of the information your presented.

You said:
"When a house is tapped into the municipal sewer, a house sewer line is run from the street to the house main cleanout. The line then continues undiminished in size under the house to form the main building drain. At any point along the main building drain a line is then run up and out through the roof, again, undiminished in size. "

My question is if a 4" drain line is installed under the basement floor and leading out to the municiple sewer, is it also required then to have a 4" vertical stack leading up through the house and through the roof. I believe my homes stack is a 4" diameter one, but only 3" comming out of the roof.

I tried looking it up on the net, and found this link for Floridas codes and they seem to be installing ones that are even smaller now. I suppose states vary greatly in their requirements, but was wondering what the opinion is on all this.

http://www.floridaplumbingperspective.com/Archive/September_Octoper_1999/f.so99.25-26.htm

Thanks for your time.

[LazyPup]

Kactuskid,
Although the differing codes take some radically differing views on venting there is one concept that they all seem to share. "The Main Vent shall run undiminished in size from the main drain through the roof." The only notable exception to that rule is that when the total length of the main vent is equal to or greater than 40' the main vent must be increased one nominal pipe size.

After the main vent has been established, additional auxillary vents may be downsized to 1/2 the diameter of the line they serve once they are 6" above the flood level rim of the highest fixture served, but in no case may an auxillary vent be less than 1 1/4".

In geographic areas subject to freezing temperatures (outside air 32deg or less) all vents must be increased to 3" at least 1' inside the attic space before passing through the roof. (Some local codes require 4")

[kactuskid]

Thanks for the reply LazyPup, I'm still a bit confused though. How is the size of the main vent established? Is the rule of thumb that it should be the same size as the main drain line? I know local codes vary but what does the IRC say about this? I assumed from the logic being these main vents basically serve dual purpose, for venting the structure and the municiple sewer, that the diameter needs to be equivalent in size to the main drain line.

You say that in freezing climates that all vents should be increased to 3" size one foot before going through the roof. Does this then assmue that the pipe diameter was less than 3". I don't understand this, I thought the drain piping needed to be at minimum 3", this would require a min. 3" vent stack then wouldn't it. I'm in Wisconsin and mainly interested in the cold climate rules.

Boy, this is so confusing, I'm basically just trying to understand a few rules of thumbs to go by. I really appreciate your input on all this.

[LazyPup]

The smallest diameter trap that is allowed on a Drain, Waste and Vent system is an 1 1/4" diameter trap, which may only be used on a bathroom lavatory sink.

By physical experimentation it was determined that an 1 1/4 trap could pass 7.5gal/min at standard gravity pressure, therefore 7.5gal/min was assigned as one Drainage Fixture Unit. Once the DFU was defined they they created a table of DFU values for each type of fixture that may be found in the structure.

The codes have tables that list each type of fixture, the minimum trap diameter required and the number of DFU's assigned to that fixture.
(From the International Residential Code)
Bathroom Lavatory 1DFU 1 1/4" trap
Bathtub/shower 2DFU 1 1/2" Trap
Shower Stall 2DFU 2" trap
Water Closet > 1.6gal/flush 4DFU N/A
Water Closet < 1.6gal/flush 3DFU N/A
Kitchen sink 2DFU 1 1/2"trap
Kitchen sink w/dishwasher 2DFU 1 1/2"trap
Kitchen sink w/disposal 2DFU 1 1/2"trap
Clothes washer standpipe 2DFU 2" trap
Laundry tub 2DFU 1 1/2" trap
laundry Group (washer & tub) 3DFU 1 1/2"
(Note that the table does not list a trap size for the water closet. Water closets-or toilets if you prefer, have a built in trap, therefore the line does not get a trap, however, the drain line must be equal to or greater than the trap diameter, therefore if the water closet has a 3" discharge port from its built in trap, the watercloset flange and drain must then be a 3" minimum.)

The table continues on and lists many other fixtures such as water coolers, Bidets, bar sinks, etc etc.

To layout the drain we first start with the "floor Plan" that shows the location of each fixture in the structure. Considering one fixture at a time we continue to add the DFU values until we know the total combined DFU load for the whole structure.

Consider a small house with two bathrooms, kitchen and laundry.

Bathroom #1
Water closet < 1.6gal/fl 3DFU
Tub/shower 2DFU
Lavatory 1 DFU
total 6DFU

Bathroom # 2 (master bath)
Water closet < 1.6gal/fl 3DFU
Tub 2DFU
Shower stall 2DFU
1st Lavatory bowl 1DFU
2nd Lavatory bowl 1DFU
total 9DFU

Kitchen
Kitchen sink/disposal 2DFU

Laundry
Washing machine standpipe 2DFU
Laundry tub 2DFU
4DFU (Laundry group May be derated to 3DFU)

Therefore the Total DFU load for the whole house is 20DFU's.

We then consult a table that lists the maximum DFU load permissible by pipe diamter.

1-1/4" pipe 1 DFU (Horizontal) 1 DFU (Vertical)
1-1/2" pipe 3DFU (H) 4 DFU (V)
2" pipe 6 DFU (H) 10DFU (V)
2-1/2" pipe 12DFU (H) 20DFU (V)
3" 20DFU (H) 48DFU (V)
4" pipe 160DFU (H) 240DFU (V)

First we must consider that the minimum line diameter that may serve a water closet is a 3" diameter line. From the table we can see that a 3" diameter line will carry a total combined load of 20DFU, therefore in this instance the proper size for the main drain, and house sewer line would be 3"

Depending upon the physical layout of the floor plan, it may be necessary to install a separate vent for each bathroom as well as the kitchen and laundry. At least one vent directly attached to the main drain (3") must be designated as the house "main vent" and must run from the main drain up and out through the roof, undiminished in size, meaning it must be 3" (Equal to the main drain)

The additioinal vents (Auxillary vents) may then be reduced to 1/2 the diameter of the line they serve once they are 6" above the flood level rim of the highest fixture they serve, but that line may be no less than 1- 1/4".

In a climate that is subject to freezing temps (northern climate) the auxillary vent must then be enlarged back to 3" diameter at least 1' inside the attic space before passing through the roof.

It is very important that we use these table to determine the proper line size.

When properly sized a should only be 1/2 full at full load. That allows the lower half of the pipe for waste flow while allowing the upper half to permit vent air to move.

If a line is too small, the load then fills the pipe and restricts the movement of vent air resulting in the water seal being sucked out of the traps.

If a line is too large the level of liquid in the line is not sufficiently deep enough to suspend and carry any solid wastes. Therefore, the solids will sit idle in the line while the liquids flow around the solids, then end result is a line that continually clogs up.

[kactuskid]

Wow, thanks a ton for all the great info. Sure clears up alot of questions, though I still have one more. Around here there are alot of 4" drain lines. My own homes main drain is a 4 incher. Then the 4" main vent pipe stubs up outta the basement floor for about 1 foot. Then the piping is transitioned to a 3" pipe that continues all the way through the roof line. My home does not exceed the allowed 48 DFU's for a 3" pipe. So, my question is, is it ok that a 4" drain was installed. I'm guessing as long as the proper sloping for a 4" drain line is followed that it's within code to install this larger diameter pipe and possibly prefferred over a 3" drain pipe.

[LazyPup]

You will note in the example i cited that the total combined DFU load for the structure was 20DFU which is the maximum allowable DFU load for a 3" horizontal line. If we were to also add a floor drain in the laundry area it would then put the total over the 20DFU and require the main drain be enlarged up to the next size (4").

Many local codes also establish a minimum diameter line size that may be run under a slab. It may be that the actual DFU load would call for a 3" line and main vent, but your local code requires a minimum of 4" underslab, in that case it would be legal to run the 4" underslab with a 3" main vent, but it would required a written approval of the local code inspection authority.

[kactuskid]

Ok, that clears things up tremendously for me. I can't thank you enough for all your time, it's really appreciated. Let me know whenever I can lend a hand your way.