replacing the old tub/shower and putting in a shower only...

newbie here (both to the site and to plumbing)... anyway, i'm gutting my 50-yr old bathroom and replacing the old tub/shower for a shower only... i'm told that i need to have 2" pipe for a shower while my old tub piping was only 1.5"... any idea how i can the 2" piping where this old 1.5" piping was?



is this going to be a major job here just to get the rough-in correct for a shower?

many thanks in advance.

In the long-term, it would be best to replace the galvanized pipe anyway. The vent piping you could keep, but not the drains.

To do it right, cut all of that out and start over with 2" drain.

The bigger part of the challenge for you will be making the connection to the building drain, which you have not provided a picture of.

Yeah, it is a major job and it's compounded since you have little or no experience. Not impossible, but there are many pitfalls you can fall into along the way. Codes can be complicated and confusing to those of us that are not pros. Definitely get rid of the galvanized pipe. The copper is nice, but 2" copper is expensive, and PVC or ABS is much easier to work with and cheaper. About the only downside to plastic drains is they are noisy. You might want to consider a plumber to do this job. Won't be cheap, but it will be done right the first time.

Fifty years ago, showers were 1.5"
They worked back then with 5.0 gallon shower heads.

We now are mandated with 2.5 gpm shower heads. If the inspector requires 2" for the p-trap and waste, then it will have to be changed.
The 1.5 will work though.
I started plumbing in 74, and it was always 2" for my installs.

Terry said:

Fifty years ago, showers were 1.5"
They worked back then with 5.0 gallon shower heads.

We now are mandated with 2.5 gpm shower heads. If the inspector requires 2" for the p-trap and waste, then it will have to be changed.
The 1.5 will work though.
I started plumbing in 74, and it was always 2" for my installs.

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I like it when rules do not take the place of experience and common sense. Good post Terry.

i spoke with my town's building inspector and he said the 1.5" is fine... i also talked to a plumber to see if he could do the rough-in work and he said he won't since i already opened a permit under my own name as the homeowner... so it looks like i'll have to give this my best shot before first...

thanks for the replies everyone...

danxp said:

he said he won't since i already opened a permit under my own name as the homeowner...

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That doesn't make a lot of sense. He can still get his own permit for his work. I'm sure the town will have no problem voiding (or changing) your existing permit if you explain the situation.