New half Bathroom questions/concerns

[Midnj]

My house was built in the 30's, and someone forgot to put a bathroom on the main floor! Anyways, I'm looking to build one where the washer/dryer were. The appliances were moved into the basement, room gutted, and now I have questions for anyone listening!

You can see pictures of the mostly cleared space here:

A couple notes on the room:
*this room is a addition off the back with a crawl space that is not in the full basement. The main stack is in the basement, just a few feet from this room.
*The cast drain and supply lines you see in the wall feed the upstairs bathroom.
*The drain/supply in the old finished part was for the washer/dryer.

My general plan at the moment is to:
Place the toilet on the left wall, and pedestal sink on the right wall(where the cast piping is), and close it all in with a wall/pocket door. I was going to run all new drains for this bathroom vented from the roof to the basement stack since I don't want to deal with modifying the existing cast drain near the location. I cleared out all the cast in the basement, however it was cracked and this drain looks fine.

Ok - My questions, and feel free to answer a question with a question:
1 - What size drain do you need for a half bath and sink? 4"? Also, what size vent pipe needs to accommodate this line.
2 - I need to replace the copper feeding the upstairs bathroom as I found there is a tiny pin hole leak on the exposed 90º fitting. When replacing, I was going to peel off 1/2" connections off for this bathroom - would that cause any pressure issues?

Feel free to post any comments, note that I'm likely going to get the plumbing work quoted out from a local guy I know but preparing to do it myself for budgetary issues!

Thanks

 

[frodo]

can you inbed the pictures instead of file format, i really do not want to down load onto my pc

from somewhere i have no idea where...sorry so picky, but i have caught virius before, my pc spent a week under the covers drinking chicken soup and drinking nyquil.
THEN>>it started liking the nyquil, and that opened up a new can of worms. not night crawlers, i could have used them to fish with.
but those long skinny yucky red ones with the white spot in the middle.
to small to stick a hook in, and not long enought to tie in a knot

 

[Midnj]

no problemo - sorry about that.

The first task will be to replace those 2 supply lines that feed the upstairs bathroom... looks like one is 3/4 brass and one is 1/2" copper?

 

[frodo]

typically, you want to run drains/ vents first, because they go where they have to go, water lines can be offset around them.


I see the room you want to plumb.

what is under this room? a basement ?

that is where the major work for drains will be.

 

[Midnj]

Right - those supply lines I want to tackle are for the 2nd floor bathroom, not this bath in question, really a separate task but needs to be done before I close the walls up.

There is a crawlspace under this demo'd room, and your drawing would be spot on except I don't want to touch the 4" cast that is there right now. Here is a look of the basement stack:

The 4" at the very top is the cast you see in the demo'd room. I was planning on drilling through the concrete under that for a new drain and tie it into the stack in that cleanout...

Here is a look where you can see the crawlspace access that is under the room.

 

[frodo]

is that the way its laid out?

if so, your job is easy.

 

[Midnj]

Sorry for not providing great photos the first time 'round. Here are some marked up:

So after looking at the 4" cast, it looks good so I'd like to just leave it as is and run a new drain 3 or 4" from that crawl space to the basement stack. If pitched enough, could I run that drain through the crawl space opening - I've drilled through this foundation before and it is not pleasant - lots of rocks.

 

[frodo]

..............

 

[Midnj]

thanks - I really didn't want to bore through that concrete...

2 questions -
1 - Is there any benefit to going with a 4" over a 3" for the drain?
2 - The roof vent pipe would be on this bump out(which is only 1 story), and probably ~6 feet from a 2nd Floors window - is that a no no? I could probably get it out to the main 2nd floor roof (yay balloon framing), but a PITA.

 

[frodo]

4'' would be better, upsizing is always better, all you need is a 2'' vent

vent pipes shall terminate not less than 10' from , or at least 3' above an operable window , door opening,air intake, or vent shaft

upc code


question is, is that window operable? do you ever use it? to make it code compliant, put a screw in the window

 

[Midnj]

Thank you - I shall likely begin some activities related to this and post updates as I go!

 

[frodo]

as far as your water lines go. pick where you want to stop replacing.

if its screw pipe [galvanized] buy a dielectric nipple, screw that into the old pipe, and tie onto it with new

IT has been my experience, RIP IT ALL OUT.

few tricks..you can bring the water up thru the floor in the cabinet instead of ripping into the wall

same with the toilet. only place you will be forced to open a wall is the tub/shower

and that can be done from the back, so you do not ruin tile