Moving the Drain Stack Pipe

[wiz561]

Hi!

I'm interested in remodeling my kitchen, which involves moving a door from one side of the wall to the other. Unfortunately though, the drain pipe runs right in the middle of the new door. Since all of the cabinets I have planned for would be re-arranged and I'd loose a cabinet, I'd like to move it.

I was wondering, the pipe that runs up to the stack is galvanized. Can I remove this pipe, move it over about 6 inches, and then add an elbow? If I remove the galvanized pipe from the stack, will the stack come crashing down on top of me? I took a picture of it since a picture is worth a thousand words...

It looks like the galvanized pipe can just be unscrewed from the iron stack, but I just want to get an opinion first before any damage is done.

Thanks!

[bob haller]

Is the pipe just a vent?

If so the easiest way is support the pipe above and below, cut out the section you want to be rid of, and use Ferncos, install PVC as the patched area.

Old stuff doesnt unscrew easy, far better to cut out less chance of causing down stream leak.

DEFINETELY SUPPORT EVERYTHING! there are hangers made for this!

If the area your moving carries waste water it will be noisey once your done

Cast and galavanized doesnt conduct sound like PVC does

[RBM]

I would just remove the whole thing, and run a new piece of 3" plastic through the roof

[bob haller]

I prefer to NOT mess with roof. It just adds a new job, requires patching shingles and new shingles may not match.

[Joe]

Your rationale for not dong it right will only result in a half baked job. RBM is right, simply get rid of the ancient galvanized and replace it all with PVC to code. The work on the roof will only take an hour at most, and unless you have a weird roof structure there will be minimal upset to the shingles. Working with the DIY friendly PVC is far easier than cobbling together a mismatched system. Functionality should trump cosmetics in this case.

Joe

[Colbyt]

From the picture you posted you have a 1.5", maybe 2" pipe connected to a 3" roof vent.

The current sized pipe replaced with PVC as illustrated in your picture will serve your purpose very well.

Vents are fine in any configuration as long as the path is always up. So moving it left or right using 45 elbows will always work (and 90's will in most cases).

If you are careful and the roof boot is not really old your new 3-4" PVC can replace the existing cast iron with no leaks. It will be a 2 person job, one on the roof and 1 in the attic to get the new pipe in place without creating problems.

Removal! One person on the roof holding the cast iron, another in the attic cutting the iron pipe below the joint. Once cut pull it up or down through the boot. Then cut out the rest of the pipe where and as possible. Reroute the pipe back to the attic and connect it to the new vent.

[Nate Nagel]

Might want to invest in some "riser clamps" to hold the upper part of the stack in place while you are removing.

commonly seen in stairwells supporting sprinkler risers, hence the name.

nate

[Mike W.]

Thanks for the info. Actually, thank you all for the info. I just got a new roof last year and I do not want to mess with shingles or anything like that. Besides, pulling the stack out seems like quite a big job, and it would be easier to just leave it there.

I think what I might attempt to do is get a few of those "riser clamps" to support the big upper iron part of the stack. Then, remove the galvanized pipe from the stack, add some elbows, and move it over. If I can't unscrew the galvanized pipe from the stack, then I'm think of maybe cutting it with a hacksaw, adding a rubber boot or pvc connection, and then move it down that way.

All that goes down the stack pipe drain is water from the sink. There is not a toilet connected to this at all.

Thank you again for all of the responses.

[fftt]

Be careful about removing support for the vent stack. As per other posts, there are clamps / supports that you can use to take the load.

One way to avoid all this extra work is to consider a mechanical vent (an air admittance valve).

Using one would allow you to support, cut and abandon the vent through the roof (of course you would have to cover the vent top side so as not to allow rain to enter the attic via the cut vent line.

cheers Bob

[Colbyt]

I think what I might attempt to do is get a few of those "riser clamps" to support the big upper iron part of the stack. Then, remove the galvanized pipe from the stack, add some elbows, and move it over. If I can't unscrew the galvanized pipe from the stack, then I'm think of maybe cutting it with a hacksaw, adding a rubber boot or pvc connection, and then move it down that way.

I did not look at the pictures of the riser clamps. Anything that will support the 40-50 pounds of weight will do the job. I have done it more than once using nothing but 2x4 bracing and metal pipe hanger wire. Support it very well before you cut to minimize potential roof or people damage.

If you use a sawsall (hacksaw if you must) and get a clean cut on the galvanized pipe, leaving a few inches of it, you can then connect the PVC to the stub using a fernco coupler ($5 or so) sold at the BORG.

The chances of unscrewing the thing after all these years is very slim.