code is 2" so..where is it reduced at?is the trap 2" with a reducer bushing inside the trap?
you will REALLY REALLY want a 2"trap..the hair clog monster doesnt visit as often.
take a look and get back as to where its reduced

It was never reduced before. I cut out the old p-trap to hook up the new drain, and it is 1 1/2". Appears to run toward the tub which is 5 feet away. Toilet is 8 ft away off to the side.

Thanks for any advice you can supply.

my advice is to cut the sheet rock out and replace the line with a size that is correct..sorry..thats not what you wanted to hear..but that would be the correct way
also..you did not say anything about a vent
it also needs a vent..
why are you tearing out the old fixture?
is it because it did not drain properly?
was it a slow gurgling drain?

Where would I run the 2" line to? The 4" toilet line?
Is it hooked up to a 2" line with the tub perhaps, but
was reduced coming out?

Replacing the shower because the tiles were installed wrong and wallboard was deteriorating. Had some problems with hair clogs, but a cleaning out down the drain every year or two took care of it. Drained sufficiently otherwise.

Find out how many feet long your shower drain pipe is, since it sounds like it's at the upper limit of being too long for a 1.5" pipe.

In some places it still is Code to use 1.5" diameter pipe for showers.
Code requires 2" for showers in most places, and has been that way for 30 years or so.

Almost nobody will want to advise you on what to do with a 1.5" shower drain; they have to operate under a Code calling for 2" diameter.

Never reduce a drain pipe size. (only increase) Therefore you are better off with a 1.5" diameter P trap if you stick with that pipe as is, and also assuming that it was correctly installed in the first place (slope of 0.25" per running foot, etc.) It could be wet vented ; find out what the distances are.

-david

you have 2 code violations that you havetold me about
1 is no vent,2- is the max length for 1 1/2" is 36"
3--is 1 1/2" p trap
but there is a loop hole on the 1 1/2" trap
if...space limitations for 2" trap, then 1 1/2" can be used
its a loop hole that can be used..BUT..is frowned on..
you need to find the connection..where that 1 1/2" ties in
then we can switch out the fitting, to 2"
and install a 2" drain line..and we'll figure out a vent
is the attic above you? you can drill a hole down thru the top plate, from the attic. and a peice of pipe can be slid down from above. then tie vent into the closest vent using the top of the ceiling joists to run it on
can you post pictures? please???pictures????

the 2" arm from a vent is 5'
that means a vent SHALL be within 5' of that drain hole
along the determined length...
pictures...if i could see it..I would have a apiffaney
that sp is not right

a answer to davids responce
the op said the plumbing material was pvc
it was the 70's that they vigeriously changed from castiron to pvc,,so that tells me it was installed in the late70's
early 80's..the upc code on 1 1/2" pvc was being used
that means the drain was installed illeagly, and not to code
probly a side job that costed a 6 pack and a pizza
or..in the 70's..a big ole bag of buds..sweet christmas tree smellenbuds..
so i think it was illigeal when it was put in, and still is
so i guess we gotta bring it up to code

ok w/e dude all you need is a reducing gromet which you put in your showerdrain should fix it in no time and no need for xtra work,you may have to go to a plumbing supply store not lowes or home depot but will do job just fine,after all all the new vavle's are water savers so that 1 1/2 pipe will handle it besides you ever seen a tub-shower they have 1 1/2 drains duh

Agree, this is true, a 1.5" drain could work well for up to five feet if the slope was done right. The (newer) code requirement for a 2" diameter allows longer length runs and more slipups, nothing more.

I did not see PVC in any posting above.

Better to remain all the same size than to reduce at any place in the run. This is important. Water doesn't drain well when it hits a barrier like a reducer: some of it gets turned back and then it starts to fight against its own current and it backs up even though it does -- in the long term-- make its way down the drain, but its flow rate gets messed up for a while just when you really need it to work.

-david

I tottaly disagree..yes..you are correct, it would be easier and faster and cheaper to just put a reducer upsidedown, and reduce the shower to 1 1/2"..yep..cheap easier....BUT>>It aint right..it is not code, in fact turning a reducer up side down is a no no
I am a professional, I refuse to do n---- rig plumbing
the correct fix for this is to go back to where it ties in
and change that fitting to 2" run the pipe over to the shower and get a 1 1/2" vent up to the attic
in the last post..5'arm is for 2"pipe
1 1/2" pipe is 3'2"
that is the maxium allowable length for a arm from the vent
and...it does not matter when the job was done and what the code was when it was done, when you work on something you are required to bring it up to code
If a plumber were to come to your house,he would tell you just what i did. if you said no...he would say..have a good day..call us if you change your mind..he would refuse to do it..or..a handy man..now he would do...he doesnt care about codes,right/wrong, your best intrests..he just wants money
in about a year or so, you and the drain cleaner will get to be buddies..I dont like the drain cleaner guy,I try to keep him away from my house..

How does the drain fit into the new shower pan? HUD code for Manufactured (mobile) Homes was for many years, and may still be, 1 1/2" for showers. I recently used a new shower pan with 2" outlet in such a home and did not reduce any pipe sizes in the run. It took some original thinking. Tell me how your new pan hooks up.

wat its not a reducer dude its a gromet and its not reducing size of pipe that is the no-no part ur an idiot

oh and give the poor lad some advise on how to tear his whole house up, this forum is for fix's and solutions not construction advise by the way im a pro UNION plumber
G-F on most of the biggest work here in town got like 46 plumbers workin for me on one job so chill, i was just trying to help the boy out and you prob some scab untrained wana be plumber anyway

Another question for the person with the shower, what is the material of the existing drain system. Is it PVC, ABS, ?

wat difference does that make all he has to do is buy a reducing rubber gromet 1.5" to 2" and problem solved just put a lil pipedope on it and beat it down around the pipe any type pipe material abs cast iron pvc coppper it doesnt matter just tell them wat u got before u buy it
good luck buddy

so..let me get this straight..you guys are plumbers
you know what your doing, your telling the guy to just slap a reducing "gromet" fernco,missionband
on the pipe and go...bull sh--
i know this is not a construction site, but you got to tell them when its wrong..he has pipe to small...no vent.
I have training...when something is wrong.have the kahonas, to say so
just slapping a reducer on there is jack leg lazy a$$ plumbing..
now..when you get through call me names and showing how intalectual you are...tell the truth..1 1/2 pipe is to small
by code [upc] it should be 2" and the last time i looked in the upc book, every ficture SHALL have a vent
and..the only fivture that using a reducer upside down on is the toilet,,a 4x3 90

no its not a mission band it a gromet,ita a little rubber ring that goes inside the drain fitting to make it wat size the plumber needs it to be,your somewhat correct on venting but also wrong a bathroom group is served by a "commen vent" which vents the toilet, sink, and tub/shower which ever you have as far as venting lngth goes each city that adopts upc also has addemdums to that code and can icrease or decrease the said lngth duh there is also lots of fixtures that reduce down lets see a mop base, a floor drain, a floor sink,trench drain,evaporater pan,a grossing table,roof drain uhmmm the list could go on for ever but i dont have a lot a time to try to school your old a$$,the only thing that is illegel in said code is reducing fittings in a waste line,but we reduce vents all the time lol "said gromet is not a fitting",so see you can read the book all day long but if you aint a plumber quit givin out advice and stick to reading the funny paper my friend and leave the advice up to us pro"s

oh and after reading my post i forgot to mention that rain leader"s are reduced all the time like a 12"horizontal to a 8" vertical hmmm read that part so. STFU

there is absoutly nothing wrong with reducing a vent
if you would read the damn post instead of try to prove your self right you would have read that i said to run a 1 1/2"vent off the 2" line..
you are correct about the addden dums..but,you dont even know where this guy lives..DUH..so how are you going to spit out addedums..I am talking UPC code..not international
I give you the gromet debate..I never use them, don't trust em.
you have failed to address the, the orginal topic
the size of the drain line..Iam waiting for your answer as to why you want to -----rig the waste line
you say your a plumber.I my self am, and I know that the drain isnt right.nor the vent,and if your a plumber than you do to..I know very well how to plumb a bathroom with 1 vent.side outlet tee..but..he has a tub/shower and a shower
thats another vent..the shower is more than 5' away..by the upc..busted..

It is PVC, a house 7 years old. There is probably a dry vent connected, but i haven't torn away the drywall to expose its connection.

My plan is to use a reducer off the drain - to go from 2" to 1.5" and continue to use 1.5" p-trap to hook up to the remaining waste line. I'll have to live with any clogs, and figure it won't be too bad, since it's over the garage and somewhat easy to access if need be.

I also asked how the drain attaches/connects to the shower pan drain that you plan to use? I do not like the idea of a reducer, very troublesome and not to any code- ever.
When I try to help -for free- I like to have the courtesy of getting all the information I need to offer my suggestions.
So the question is important. Does your shower pan install like this?

Here is a link that might be useful: Like this?

The drain is a kerdi drain.

As you probably already know, the Kerdi drain is available for either PVC or ABS piping, so selecting for your piping type is important. If you are confident that the 1 1/2" piping meets with any code applicable to your residence and also meets with your approval, then hookup requires a pipe that has OD of 2" piping and ID of 1 1/2" piping. Get a short piece, perhaps 12", of 1 1/2" PVC (your piping) pipe and a 1 1/2 coupling. Using the proper primer and cement, install the coupling on the pipe and let it set for a couple of days. Then take that assembly to a a machine shop to turn the OD of that coupling to the size of the OD of 2" pipe. Really quick and easy in a lathe. Now you have a pipe that will mate to the Kerdi drain and will mate to your present system. Part of the coupling projects past the pipe. Cut off any part of the coupling that is not needed for cementing to the Kerdi drain. Any clogs due to the stepdown will be right in the drain assembly, remove the grate and clear when and-as necessary.

A better way would be to use a repair coupling that will slide all the way onto the pipe- but it is easier said than done. With the coupling and the pipe end even, there will be no step at that point. The end result will be a 1 1/2" pipe with one end the same size as 2" pipe. Buy a few couplings for practice if necessary. Prime and then apply cement to both pipe and inside the coupling quickly, lots of cement, and assemble them quickly.

Replacing the shower because the tiles were installed wrong and wallboard was deteriorating.

Sounds like... maybe gypsum sheetrock was used instead of true cementboard? Also maybe shower pan membrane was not brought up high enough?

PS: I understand Kerdi makes it easy to bring their membrane ALL the way up, 6' + high! I will probably be using Kerdi next time 'round...

For crying out loud, John Whipple, please stop resurrecting OLD threads. This one is SIX YEARS OLD. This practice of searching a bunch of terms and posting on old threads in order to get your name on as many as possible clutters up the board with a bunch of nonsense that benefits only the spammers. If the current, relevant questions on the board don't benefit your advertising schemes, kindly check back later and post in a timely manner.

Sometimes those fittings don't come in as sleek as a fitting and a large one is needed. They tend to look more like this one.

From my research I find that the flow rate of water has a lot to do with how far the water falls to the P-Trap. So showers where the fall is less or the pipe goes off on an angle tend to have slower flow rates. Careful if you are adding lots of shower fixtures, live in the US and this might net a failure. I like to see abut 5"-7" of drop to the P trap myself.

Often in a condo environment you are removing a tub and adding a shower. The old tub line needs to be removed so the new drain line and drain can be set. Remember to factor in Fire Stopping first.

On many jobs my little Dremmel works out well when there is not much space to cut.