How to install new shower fixture plumbing.

[saturdayplumber]

I am looking for how to properly install a new shower/bath fixture, with the fixture valve made of cast brass body and the water supply pipes in my home made of galvanized steel.

Also, where can I get a copy of the plumbing code....and will I be able to understand how to use it when I get it?

Thanks,

Saturday Plumber

[LazyPup]

let ma answer your second question first,

Where can I get a copy of the plumbing code....and will I be able to understand how to use it when I get it?

Sadly in the plumbing industry we do not have a national standard code such as is used the in Electrical Trade.

In the plumbing trade we have:

The Inernational Residential Code
The Uniform Plumbing Code
The BOCA Plumbing Code
The SBCCI Plumbing Code
The California Plumbing Code
The ICC Building Code (Plumbing section)

And a host of other state and local codes.

Typically the actual code books cost about $60 each in hardbound or $75 in loose leaf. (The advantage of loose leaf is that you can just purchase the updates then extract and replace pages to keep your book current, otherwise you must buy new codes every year.)

You would first have to contact your local authority to find out which code they have adopted for use in your jurisdiction. This can be very confusing in some regions. By example, here in W.Pa/E.Oh where i am presently working each municipality is its own governing authority, therefore right here at my house I must use the International Residential Code, on the opposite side of me street which is another community they use the 2002 BOCA code and in Brookfield, which is 4 miles away they use the 1996 BOCA code with local ammendments and out in the county they use the Uniform Plumbing Code.

At best, the code books are very confusing. There are no illustrations and the books are arranged in categories that often dont make a lot os sense to the layman.

by example, let us consider the drain lines for a bathroom. First we have to know what fixtures are going to be installed and use tables in the code to determine the drainage fixture unit load so we must check the chapter on Drainage size and materials.

The lavatory is rated at 1 DFU (drainage fixture unit), the tub is 2DFU's and a toilet with 1.6> flush is 4 DFU while a toilet with a 1.6<gal/flush is 3 DFU. There is an exception that allows a bathroom group, (tub,toilt and lav) to be rated at 7 DFU's but if you install a second lavatory sink you must then compute it all by individual loads.

Turning now to the chapter on traps we see that a Lavatory is required a 1 1/4 trap, while a tub requires 1 1/2", a shower stall requires a 2" and a toilet gets no trap (toilets have a built in trap).

We now consult a table to see what size of lines we need by the number of DFU's discharging into the line.

Each branch line may be no more that 1 nominal trade size larger than the trap it serves but a toilet must be on a minimum of a 3" line.

We must then turn to another chapter in the code on vents to determine the maximum distance the line may run from a vent without requiring an additional vent.

Then you must consult another chapter to determine where the cleanouts are required.

Typically an approved apprenticeship in the Plumbing Trade requires working 40 hrs a week under a Master Plumber plus attending college classes two or three nites a week for the entire four years. Ninety percent of the college training is taken directly from the code book as your only text and even with all of that, the average failure rate for the Plumbing Exam is 75% fail on first time testing, 50% on second try and most plumbers end up taking the exam 3 to 4 times before passing. (Keep in mind that the test is an open book test and you must come prepared with the most recent copies of the codes plus pay an avarage of $250 non-refundable testing fee for each try. You must also wait 6months between testing so by the time you go for testing the third time the code books have undergone their annual change and you must then buy need code books for the exam as well as pay the testing fee.

Fortunately there is an easier method for the homeowner, handiman or even practicing plumbers to get a heads up on the codes.

There is a very fine book called "Code Check Plumbng"
printed by Taunton Press
ISBN 1-56158-624-2
price $17.95.

(I have never found this book on the shelf in a bookstore or home supply book shelf, although I did manage to convince my local hardware store to keep a couple in stock. Actually that was very easy, once I showed him my copy he dicided he needed one for the store anyway. You can easily obtain it through an online book dealer or special order at your local book store.)

The book is a very handy 8.5 x 11 set of spiral bound, plastic coated flip charts set up by category for quick reference. The entire book is plastic coated so it will hold up to rough service on the job as well as resist water for those occassional spills or getting caught in the rain. The book fits very nicely on a clipboard under your notepad so it is always handy. In fact, i personnally rely upon this book almost exclusively when answering the posts in this forum and we have adopted it as a primary teaching tool for our apprenticeship classes. In my opinion anyone who is even contemplating a serious plumbing project will find this book one of the best $18 investments they ever made.

Code chech also prints books on Electrical, HVAC. and Building (the general building and mechanical codes.

Now for your first question, You water lines are galvanized steel and you have a brass body fixture.

There are a couple of things you could do. You could run the steel line all the way to the fixture and put a union near the fixture for final connection.

You could also use a dielectric nipple to transistion from steel to copper, then make the final hookup with sweat copper pipe.

[saturdayplumber]

Thanks LazyPup for the background information on plumbing codes. Also, I will check into the book you recommend.

To be more specific about my shower fixture plumbing project.......my question is mainly about how to properly choose the piping materials to use.

Of the two options you have listed in your response, my preference is to just run galvanized steel lines all the way to the fixture and put a union near the fixture for final connection. This is the easiest for me to do. I have several concerns with this type of installation, 1) I read that corrosion of the steel pipe where it is in contact with the bronze is a serious problem 2) Does this meet code? and 3) If in the future I want to replace all the Galvanized pipe in my 35 year old home, this shower piping in the wall will all ready be taken care of.

As background information, I have a one story home and the hot and cold galvanized steel water supply lines are in the attic. There is a tee fitting in each of the cold and hot water supply lines (in the attic) for the lines to the shower fixture. Those lines to the shower fixture start at the Tee and go through the top plate of the stud wall and then on down to the fixture.

The second option you have listed in your response, to use a dielectric nipple to transistion from steel to copper, then make the final hookup with sweat copper pipe sounds like a good option to avoid problems with the dissimilar metals. And here, I am assuming that copper and brass are not considered a mismatch of metals.

A third option would be to use a 6" hardened brass nipple in place of a dielectric nipple. (I saw this on your posting "JOINING DISSIMILAR PIPE ILLUSTRATION".) The nipple would screw into the tee in the attic. This might give me a little more room to work. I don't know if this meets code or how well it stops corrosion.

Comments from anyone on what direction to head will be greatly appreciated.
Thanks,



Saturday Plumber

[LazyPup]

You may use any approved material, the choice is your.

The codes allow galvanized iron pipe, copper both rigid pipe and roll copper, and CPVC.

The code prohibits directly coupling copper to any Ferrous pipe or vessel (iron or steel pipe or tanks)

To make a transition from copper to iron you must use a dielectric nipple, dielectric union or a 6" hardened bronze nipple.

You may connect iron pipe to a brass or bronze valve or fixture.

Iron pipe is seldom used now becuase it is more labor intensive to cut and thread than running copper or CPVC and iron pipe tends to corrode severely on the inside of the pipe, but that corrosion takes years to form before it becomes a real problem.

You can run galvanized iron pipe all the way, but you would probably have to cut and thread a length of pipe to get the fit you need. You may find it easier to disconnect the line at the tee overhead, install a bronze nipple, then use a copper male thread adapter and run copper down to the mixer.

If you are planning to remove the existing iron pipe and repipe the house, i would recommend you run copper because it is cheaper and a lot easier. I have been doing a lot of repiping and right now it is averaging about $300 in materials for the copper pipe, fittings and required valves for a basic two story three bedroom one bath.

Before you start that project let us know and i will give you a heads up on line sizing and all the required valves and such.

[saturdayplumber]

Thanks for all your help LazyPup. I used Galvanized Iron Pipe and the installation went very smooth.

Saturday Plumber

Saturday Plumber

[MartinR]

I found the "Code Check Plumbing" book at my local Home Depot.