Covering a waste pipe

[boober]

I was asked to look at my Aunt's leaking ceiling. When I crawled up into the attic, I discovered that she has a copper waste line. The original plumbers had installed it at a 90 degree angle to run it from the front side of the house to the back for aesthetics. The pipe comes out of the ceiling, up about 1,5 feet and then 90s for about three feet and then 90s back up to the roof. The pipe must have filled with water over time and freezing caused the pipe to split in the middle of the lateral run. I was debating on just installing a patch over the 6" split and putting a vent cover on the pipe outside to stop further rain penetration, but I was unsure as to any possible reason why this would be a bad idea. I also considered replacing the interior pipe and adding two 45s instead to allow the water to actually drain down instead of pooling at the lateral run. I hesitate on doing that for fear that the boot make be disturbed and will start to leak and I don't want to open the whole roofing issue.

So does anyone know if putting a vent cover on will reduce or cause issues with drainage, or have suggestions on the best type of cap(cover) to use? Any help is most appreciated.

I was think of using something like this- http://www.ventingpipe.com/display.cfm?sword=361&source=****** or this- http://www.antonline.com/p_8104-NX_371698.htm

 

[Jadnashua]

All drains and vents should be sloped to allow any moisture (rain, snow, condensation, waste, etc.) that might accumulate, to actually flow down and out to the sewer. If you can change the run so it has slope, you should be okay. Copper costs are quite high now, so you should take the parts you cut out to a recycler for the value. You can get no-hub connectors to transition to pvc, and you may be able to just poke a piece of pvc out the roof's boot after pulling the copper out.

If you opt to replace the copper, try to rework it so it has slope - 1/4" per foot is desireable.