Roof vent cleaning

[andyvh1959]

I swear the more I live in my house the more dumb *** things I find. The kitchensink/dishwasher is slow to drain, gurgles and burps. So up to the roof I go to check out the plumbing vent stack. I pour water down it and it stands in the upper level of the vent stack for hours/days, so there is a clog. I tried pouring plumbing chemical cleaner down the vent and eventually it drained through over days but never cleared the pipe. So into the attic I go to find the vent stack makes a turn and runs almost horizontally to the outside wall:

Now, I understand necking down the stack to a pipe size that will fit in the wall. But shouldn't the run of the pipe have about some pitch to it to insure any rainwater that gets down the stack will drain down into the sewer line? The house was built in 1973 on a heavily wooded lot, and far as I know the vent stack was never "hooded" in any way to keep leaf debris, critters/birds, rain/snow from getting into the larger vent stack diameter and building up at the obvious step where the larger pipe necks down to the smaller pipe. So now I have to disconnect the horizontal run of the vent stack, clean it out as i suspect it is clogged solid, then reinstall the run with a downhill slope to it. Any recommendations to add?

Up on the roof I did make a breather cap setup that sits over the pipe but fully allows air to flow up under the cap and vent the stack.

 

[Showkey]

Birds falling down the pipe is common.

 

[jack stand]

If you're able to use a pair of 22.5* and save a little vertical space by using "street" fittings...
(Get rid of the 2 90's)

 

[andyvh1959]

That's what I'm thinking, though the elbow way in the back near the soffit may be tough to reach. It does have a rubber sleeve coupler on it that allows for some angular displacement. I may install a rubber 90 below the neck down area if it is less of a drop than a black pipe 90, and attach it a bit higher up to create a slope down to the elbow in the soffit area. Far as I know there is code requiring the vent run to be horizontal so I can position the vent pipe run as best suits draining.

At least when I get up there to do it I'll take out the black pipe to clean it all out.

 

[nadogail]

Back in the day, when I was able, I frequently carried a drain auger up a ladder and ran a cable down vent stacks. I no longer climb ladders, my wife pulled my ladder climbing card on my 67th birthday 15 years ago.
Sometimes grease builds up and the cable can punch right through it.

 

[andyvh1959]

Well, I decided to go at it, clean the clog, and correct the horizontal run of the vent pipe. It was one of those times when a quick stop at ACE hardware picking up other stuff and "oh yeah, I should get a flexible 2" rubber 90 for that vent stack" moments. Back home up in the attic, disconnected the vent stack, took out the black pipe 90 and immediately found a dirt/debris plug inside. Cleaned that out, probed 36" into the pipe run to make sure nothing else plug it from there, and used a mini-vacuum to **** the dirt out of the run and reconnected it all with the new rubber 90, and raised the vent stack slightly to get some slope in the run. About an hour later I'm cleaning up.

The sink drains a bit better but still burps bubbles a bit. So I'll flush the vent pipe from the top down with a chemical clog cleaner and water. Hopefully that gets the rest of it cleared. My bet is the vent stack was never cleaned since 1973.