removing 4'' cast iron stack

[tk2]

I,m remodeling my first floor bathroom, I want to remove a 4'' cast iron pipe and replace it with pvc and reduce the size if I could. This is from the bathroom floor up to the roof, there's no other connection on the pipe..The only fixtures I have are sink, shower and toilet...that are connected in the basement..attached is somewhat of my existing DWV design....

[master plumber mark]

go rent a rigid cast iron cutter and
have at it.....


alll you got ot do is is snap it off in sections....

but it is rather heavy so be careful

[Cass]

Why do you want ot do this?

[tk2]

Why do you want ot do this?

I need to reposition my toilet and this wye is up against the baseboard I need to replace ....I really don't what to mess with that cast iron, I don't think I have another option....If I do remove this pipe, what size can I use?

[Gary Swart]

If you remove the cast iron stack, you need to clamp it to the upper floors so that when you cut it loose it doesn't come down on top of you. It is extremely heavy and takes some serious clamps. Do not be under it when you cut it.

[finnegan]

You can reduce the 4" vent portion of the pipe only if you have other vents going through the roof. The cross section of your vents need to be equal to or greater than your largest waste pipe. So, if you have a 4" pipe entering your house, you need a 4" going out the roof or a 3", 2" and 2", etc.

[tk2]

You can reduce the 4" vent portion of the pipe only if you have other vents going through the roof. The cross section of your vents need to be equal to or greater than your largest waste pipe. So, if you have a 4" pipe entering your house, you need a 4" going out the roof or a 3", 2" and 2", etc.

THANKS FINNEGAN,tk2