A simple miscalculation

[MiamiCuse]

OK I know I could have avoided this but how a simple miscalculation could result in a total disasater.

I am trying to carve a hallway connecting two sections of my house that is currently separated by a garage. It so happens in that area of the garage the elevation is the same as the house, the elevation drop is in a different section of the garage.

First of all I have no plans of the property, nor does the city, nor does the previous owner. I have mapped a lot of it myself my crawling through the attic a lot, so the hallway has to be done by punching through the garage wall, then into a bathroom. I knew there is a vent stack near there...

So I got up to the roof, measure the distance from the roof edge to the stack, 7 feet. OK.

The hallway is to be 3 feet six inches wide, so 4 feet or so from the exterior wall, much less than 7 feet, perfect.

(Only I forgot my roof has a 5 feet soffit overhang...idiot...)

That is the miscalculation...

So I started to break the wall in the garage and here we go:

a cast iron vent straight through the middle of my hallway. I stared at it for an hour, could not believe I forgot to deduct the soffit overhang, and now I am looking at this.

I don't want to open the slab up to relocate the vent, this is cast iron and will be nasty and tricky. I told my wife we may have a nice looking decorative column in the middle of the hallway and she is not smiling...I told her may be I will reroute the vent sideways and up above grade, and so the hallway may have "stair master" right there she can do her daily step up and down there and still she is not smiling...

MC

[RicodJour]

You have to stop doing this stuff. The tub spout in relation to the rest of the plumbing should have tipped you off to the vent location.

It's pointless to answer your questions after you've gotten into a "situation". Start asking the questions before you start mucking about.

R

[Michael Bulatovich]

Tub spout?

Small exploratory holes, carefully placed, are a good move too.

[Michael Bulatovich]

I'd say that you don't have any choice, other than retreat. You can go to ABS easily for the stack vent, use the same roof hole, and it's not that big a deal. Not compared to what people will think of a stack in a narrow hallway. Do it right.

The hallway's supposed to lead to something, and be wide enough to accommodate human passage, right? Looks like it's only going to be 28" clear...

[MiamiCuse]

No not a tub spout RicodJour, that's the end of a P-trap. There used to be a small sink there. Like I said I knew there is a vent stack just for some reason miscalculated. I thought it was further down near where the shower is.

MC

[MiamiCuse]

Well the good news is since it's a vent, I could use 90 degree sweeping elbows. The section above the ceiling line is very tight since the roof is very low at that spot, don't know if there is room to do two elbows with a horizontal section across the joists and rafters there, but that would be a simple problem with having to relocate it below the slab I am guessing there is a grade beam below that wall. I don't know, have to open a trench to look and see.

It will be 3'6" clear if the vent stack is not in the way.

[MiamiCuse]

The configuration of the hallway is in an "L" shape, connecting the two sections of the house so there is really no way to do it otherwise. The only other option I have is to cut the vent off and do a 90 degree elbow horizontally, and then raise the entire floor elevation of the hallway by like six inches to conceal it. But that does not make sense to me.

I think all I can do now is to open a trench in my slab and pray that there is not a grade beam under that wall. For PVC pipes, I can make small trenches and some plumbers can work with PVC fittings in tight spaces by reaching their hands down to do the cutting and connecting, but for cast iron it's major work I would have to make large and deep holes. Not looking forward to it.

[MiamiCuse]

Normally I would have done this. However, since this is a concrete wall, one side of it in the garage is full length shelves for tools, and the other side is a bathroom wall, which was tiled from floor to ceiling, there is no way to make exploratory holes without doing a small demolition to cut away the shelves and break sections of tliles. Now even with hindsight I still think this is the case because the tiles there were set on mortar with those chicken wire mesh stuff, so it would be a nightmare to tear a hole there.

Well now I have a BIG rectangular hole LOL.

[Kris Krieger]

"MiamiCuse" wrote in news:rYWdnQMfNLj20X7bnZ2dnUVZ [e-mail]:

I assume all of that copper piping is going to be moved...? What is on the other side of the concrete block? Wht i'm thinking is, take the concrete bock back to what looks like a wood support (on the left side of the photo), put soen sort of sheathing over the pipe, and turn that small opening into s "lite" - use ribbed glass, glass block, or some other decorative patterned or frosted glass. Or make a stained-glass window to go into the space! You can go with something abstract, or use a "long" subject - a heron with cattails, for example, or a morning-glory vine - or so on.

THe trick is to not *merely* see "a pipe in the hallway". THe fact and reality is: It is there. Remember that a "feature" is very often something that could have been an awkward eyesore, but someone instead chose to turn into a creative opportunity!

[Michael Bulatovich]

And if it is?

[Michael Bulatovich]

If the wall at right has a footing, can't you move it to the right in the photo? If you come at the roof hole parallel to the roof structure your pipes can be between the ceiling joists for more room to turn....

[DT]

Am I correct in thinking it is no longer used as a waste line in your new plan? Since it is just a vent, not a waste line, you do not need to use sweeping elbows. You can use pvc vent elbows, which have a sharp, 90 degree corner. Take out a bit of concrete, convert to pvc below the floor line and run the new vent over to the wall. However, the line shown may drop straight down into a line that *is* a waste line, you should be ale to tell from the locations of other fixtures in the house.

But, by code, this new vent line cannot have a horizontal section below the water line of any sink, etc. Since this appears to be a secondary vent, not the main vent, the rule on horizontal sections might not apply, you would have to ask discretely around the building department. If it isn't getting inspected, don't ask :-)

Heck, if you are not going to have a fixture requiring venting here, take the whole damn thing out.

[Michael Bulatovich]

I was wondering why he wasn't proposing that, unless MC's going to direct you through the bathroom to somewhere else.

[MiamiCuse]

I am not sure. I am not eliminating the sink, they all will be shifted about 42" to the left to make way for the hallway. There is another vent further down from the laundry drain that I may be able to tap into, I am not sure, have to consult a plumber before I figure out what to do.

Thanks!

MC

[MiamiCuse]

about 27". If I build a small sideway wall to conceal it it would further reduce it to 25".

[MiamiCuse]

The stack is shared by the sink, an adjacent toilet and a shower. So I cannot just eliminate the vent without tapping into another vent. I am getting a plumber out to take a look as I don't really know which way the drain line runs (no plans available). Should know more once the plumber looks at it, or may be he will need me to open up the slab to look at it.

Thanks!