Installing a pipe into a cast iron down pipe

[KCBrewer]

What you have is 4" cast iron pipe. Pretty standard on older houses.

DO NOT attempt that 4" fernco boot if this is on a vertical stack. That will not support the rest of the stack. As mentioned, you will have a mess of cracked pipe/joints if that stack is not supported. 4" cast iron weighs 16.4 lbs/foot. You do the math.

Honestly, if you've never worked with cast iron pipe, I don't know if this is something you want to take on yourself. If could easily turn into an expensive repair if not done right.

A suggestion. If this is not going to contain any large solids, drain into a bucket or drum and use a sump pump to pump it to a drain somewhere else.

 

[Max232]

I'm new here, haven't figured out posting pictures and stuff. You can pull this off with a cast/ductile iron saddle fitting. It is a clamp type fitting with threaded outlet. Just install it, drill your hole and thread your PVC adapter in it.

 

[kladue]

The 4" cast iron waste line can be cut and a 4" X 2" PVC or ABS combination tee can be installed with the branch as low as practical. Do not try the chain cracker cutter as you will probably shatter the old 4" cast iron, use a grinder and cuttoff disk or carbide sawzall blade to cut. For connection of the plastic to the cast iron there are rubber/stainless couplings made for this task, slide couplings over joint and tighten. Once the drain has been run to the sink you will need to extend the drain vertical to near the ceiling and install a vent fitting that lets air flow in and keeps sewer gasses from leaking back into the room as you will not have a vent stack to tie in to. As with all drians the line has to be graded 1/4" to the foot on horizontal runs, so starting low will be a good idea if you have far to go. Use longer radius drainage fittings, not short radius pressure fittings for drain work as the latter would probably get plugged up.

 

[pickles]

You can't just install a vent near the ceiling. Venting this sink is a whole other issue. I suppose you could use an auto vent but I don't think that's code, but where he's going he don't need no stinking codes.

 

[birvine]

I'm no plumber so excuse my terminology or lack thereof. Is there any other spot in that room where there are pvc drain pipes or even a floor drain near the wall? If so, you might be able to install one of those sealed tanks with a sump pump inside that pumps the liquid out through a line to a drain pipe located elsewhere.

B

EDIT: I have seen them on the shelf at both Canadian Tire and Home Depot.

 

[cyclogenesis]

hehe.. I should go get the popcorn..

Yes.. I am below ground in my basement.. Hence the desire to drain out through the plumbing...

In Summer cooling water (tap driven) will actually be going outside to water but I need a sink..

 

[pickles]

The answer is to do like we've said and cut the pipe and add a tee. The Fernco is perfect, bu it is entirely made of rubber so you must secure the above pipe with hangers, these are readily available at the local plumbing store. Cast iron is very brittle and f'ing hard, so use one of the methods I mentioned earlier to cut it. The sink drain will need vented. You can not use the stack as a vent if fixtures above use it as a drain ( which they do). You could probably get away with an autovent or you'll have to find another way to vent it.

 

[starman]

Use two rubber slip connectors with stainless bands, not the flex t. Infill the cut with 4" pvc top and bottom of a 4x4x2 sanitary t. Make sure and keep it low enough to pitch your drain from the basin. For the love of beer, use a p-trap at your sink.

For your cuts, they make a diamond dust covered sawzall blade that while pricey, will last forever if you keep it wet. Each cut could take a good 15 minutes. If not get 3 or so blades. CI is some tough stuff. Leave the breaker chain for the pros.

The sink must be vented to meet code. It should not tie into a pipe that has other waste still comming from above. Thats called a wet vent and not usually allowed. That said if you are close to the stack, the sink would function roughly ok without one. You might get gigged at a home inspection if youre trying to sell in the future.

Do you have a second probably smaller pipe close by? Its not completely out of the question to have a vent already down there. Post a pic if you can.

 

[cyclogenesis]

Thanks for the responses! I might look at a sump.. might be the simplest option..

I do have a laundry trough in the basement but it is in a far corner of the room (and not near a window which I need for venting...

 

[lschiavo]

If you have a laundry sink, why can you not tie your new sink into that drain? Sounds a little farther to run but cheaper than a sump. Maybe you should draw a picture or take a few.