Hi everyone. I’ve done a lot of lurking here and have picked up many great ideas. I am currently building a cabin in NE Minnesota and have a question on the plumbing vents. I am placing a steel roof on the cabin and understandably don’t want to be punching any holes in it for vents. I will have two vent stacks, one on the main floor and one upstairs, the mainfloor vent will have a kitchen/bath off it, the upstairs will just have a bath. My questions are:
1. For the mainfloor plumbing can I just run the vent out the sidewall as opposed to the ceiling? Even better case would be can I vent it into the soffit area?
2. For the upstairs bath, can I just extend the vent stack up past the fixtures and then put in a studor valve on it. It will be in an unfinished closet area so it will not be enclosed and have good access to air. For that matter, I could also run the main floor vent into an area that will be sealed off and put a studor valve on it.
3. If I have to vent these through the roof, what would be the best way to seal these up. It’s a 12/12 pitch roof. Keep in mind the steel is already on.
Thanks for all the help.
Replies
Re the sidewall vent, they are now allowing that here under some circumstances--clearances to windows, the soffit, etc. Check with your inspector as to what s/he will want to see. Before the '03 IRC was adopted here there were no sidewall vents allowed.
Codes aside, you will not want any vents to be near windows, especially under soffits. They smell. A lot.
Studor vents eventually will stop working and then you will have gases inside your house and outside the pipe, trapped in a closet or wall cavity. Then it will permeate the house. Get the idea?
If there was a better or equal way, in this situation, everyone would be doing it.
There are stock boots available or you can have one made special which will not comprimise the metal roof. The vent pipe extends through the boot to exit through the roof.
F
There he goes—one of God's own prototypes—a high powered mutant of some kind never even considered for mass production. Too weird to live and too rare to die.
—Hunter S. Thompson
from Fear And Loathing In Las Vegas
906.0 Vent Termination
906.1 Each vent pipe or stack shall extend through its flashing and shall terminate vertically not less than six (6) inches (152 mm) above the roof nor less than one (1) foot (305 mm) from any vertical surface.
906.2 Each vent shall terminate not less than ten (10) feet (3048 mm) from, or at least three (3) feet (914 mm) above any openable window, door, opening, air intake, or vent shaft, nor less than three (3) feet (914 mm) in every direction from any lot line; alley and street excepted.
906.3 Vent pipes shall be extended separately or combined, of full required size, not less than six (6) inches (152 mm) above the roof or fire wall.
This is right out of the UPC uniform plumbing code>
I did this when I first built, had the vent stop in the attic. it was legal. after about six months I had a mold growing on my plywood. Go throught the roof, no other way. I have a metal roof too.
Plumbbill gave you the code, now go to a plumbing supply house and ask for a flashing boot for a metal roof.
The boots have a flexible base with a rubber gasket under the metal. The sleeve were the vent passes through is also rubber and will flex to any roof pitch.
In use, you mark and cut your roof penetration, then run your pipe up. Add a generous bead of polyurethane caulking to the bottom of the flashing boot , slide it down over the pipe, and screw it to the metal roof, through the metal flashing flange. Use the same screws you used to install the roofing metal. After it is screwed down run another bead of caulk around the outer edge of the flashing boot. The flexible base and rubber gasket will bend easily over the ribs and/or contour of the metal roof.
The one additional step I take is to add 2x blocking around the opening to give the screws something more to grip than the sheathing board, or metal if the metal is on purlins only.
Don't be afraid of it, and if you don't want to see the vent(s) reroute them in the attic to come out on the back roof of the house.
Dave
always run the vent on back side of roof. that way you dont have ugly view of vents from road
Good explanation. It sounds like he hasn't run the vents yet, so he can drill thru the roof from above to avoid going thru the ribs.... much better and easier to go thru a flat area on a roofing pan.
Thanks for all the advice. I can run one vent through the back side of the roof but the other vent I cannot route to the backside because it's a cathedral ceiling design and there's no attic to make that work.
Can I run the upstairs vent horizontally for aways below the fixture level? Here's what I'm thinking. I run the main stack up inside a closet and then branch it over to the toilet. But inside the closet but above where the branch goes to the toilet I put in another 90 degree and run horizontally between the i joists about 15' and then turn it up and out. Will that work? Heck, at that point I could even tie it in with the other vent stack.
Thanks again.
I wrestled with this concept back about a year ago ( I put a 50 year shingle roof on). I knew no flashing would last any 50 years. So in the end, I combined all my vents and have one 4" pipe going out. While my roofer was putting the boot in for me (it was after the roof was done), he put a small slice in the rubber part of the boot. So I got another one and used it, but I then put the damaged one over top the other one. I left it about 4" or so off the roof. The theory is to keep the sun off the primary boot since it's UV light that pretty much does rubber in. I assume heat takes a toll on rubber too, so maybe I only extended the life of that boot by 5 minutes, but what the heck I had the second boot sitting right there.
The boots on my old roof all failed at the rubber gasket that gripped the pipe, so anything you can do to extend that joint is best.
RE: studor vents. I haven't hooked up my plumbing to the stack that goes out my roof. My plumbing is entirely capped by studor vents. On occasion, air will force it's way back up through the toilet when the washing machine (in the basement) drains. I assume the wash machine is backing up the main sewer line out of my house, so I probably just need to snake that out. No big deal for now. BTW, I'd bet a lot of money a Studor vent would last longer than any boot. I also don't see anyway a studor vent could cause mold in an attic as one poster said. But hey, I guess it could happen, especially if the vent were bad.
If you can find a discrete place to go out a sidewall, then go over and clear your overhang, then go up, I'd think that would pass code. I'd have done it on my house, but it just wasn't going to work out nicely.
MERC. (not a plumber)
My roofer removed and replaced all the vent pipe jacks on my current job in about 30 minutes. They were 20 years old and the rubber was a bit toasty, but no leaks we could see. Just good practice, and easy to do.
I figured I would just have to replace the boot on a schedule since we know it won't last 50 years (like my roof is supposed too). I guess for the cost, it's cheap insurance against a leak. Probably take longer to get up on my roof than to do the replacement.
MERC.
I can definitely see the value in a second rubber washer around the pipe, over the actual boot... sort of like a storm collar on a mechanical vent... but absorbing the UV rays instead.
You're not allowed to run the vent horizontally below the flood rim of the fixtures. Sounds like you already knew that. You can run it horizontally once you're above, as long as you have slope... not actually horizontal.
It's this damn modern architecture! Nowhere for the mechanicals...