How feasible is it to vent plumbing through siding and not roof?
December 10, 2023 8:57 AM Subscribe
I live in a very rural area. It is very hard to get construction , roofing help. my plumbing vent goes through roof and has been knocked down by snow 2 winters in a row. Can I just bend it and vent it through the wall to outside?
I'm not going to do this myself, I'm going to try to get some help to do it right but my plumbing vent, installed by a plumber, keeps getting knocked down by snow build up. I would like to just avoid this altogether by just venting it out through a wall to the outside. Is that even possible?
The primary reason is I have gotten so old I can't climb on the roof anymore and to get someone to fix something on your roof could take years and chances are they will be incompetent. Where I live. This is a tiny home I use as a guest house.
Problem 2. It is leaking around the chimney in my main home. I used to be able to climb my own roof but can't anymore. I found one person who would come out and they wanted 3,000. That's beyond my budget. And I have decided what I want to do is create a green roof mainly because I am in a high wildfire area, also because the roof needs to be replaced now anyway. But I would still like to keep my wood stove. But I would want to knock down the chimney so I don't have to deal with leaks around the chimney with a green roof. Can I have a chimney that goes out a wall to the outside? I think I would like to build a whole new chimney. Not sure if that is an option - to go sideways.
I'm not going to do this myself, I'm going to try to get some help to do it right but my plumbing vent, installed by a plumber, keeps getting knocked down by snow build up. I would like to just avoid this altogether by just venting it out through a wall to the outside. Is that even possible?
The primary reason is I have gotten so old I can't climb on the roof anymore and to get someone to fix something on your roof could take years and chances are they will be incompetent. Where I live. This is a tiny home I use as a guest house.
Problem 2. It is leaking around the chimney in my main home. I used to be able to climb my own roof but can't anymore. I found one person who would come out and they wanted 3,000. That's beyond my budget. And I have decided what I want to do is create a green roof mainly because I am in a high wildfire area, also because the roof needs to be replaced now anyway. But I would still like to keep my wood stove. But I would want to knock down the chimney so I don't have to deal with leaks around the chimney with a green roof. Can I have a chimney that goes out a wall to the outside? I think I would like to build a whole new chimney. Not sure if that is an option - to go sideways.
It might be easier to install pipe braces/supports, which are designed to solve this problem. Plumbing vents should be vertical so the warmer air inside rises out and draws sewer gas out with it. Draw doesn't work very well with horizontal pipe runs. Which is also relevant for your wood stove: a horizontal chimney is not going to draw as well as a vertical one. In both cases, wind may cause a horizontal vent to blow the wrong way which is inconvenient for a plumbing vent, but can be catastrophic for a burning fireplace / wood stove.
posted by seanmpuckett at 9:44 AM on December 10, 2023 [5 favorites]
posted by seanmpuckett at 9:44 AM on December 10, 2023 [5 favorites]
You can definitely install an insulated chimney that runs up the outside of your house. You use double-wall stainless chimney sections for this, which have insulation between the inner and outer pipes. This is a very standard thing to do, but it isn't cheap. Your woodstove needs to be fairly close to an outside wall to make this work and of course the chimney needs to terminate at the proper height above your roof per local code.
This is generally not a great idea from an efficiency standpoint though, as having as much of your chimney inside the heated building envelope means you get as much heat a possible out of it. The more of it you put outside, the more heat you lose.
Expect to spend a few thousand, assuming you're dealing with a single story.
Sounds like your plumbing vent needs bracing or perhaps relocating nearer the peak of the roof, if possible, assuming you're dealing with a roof that sheds snow and the vent is near the eave.
posted by ssg at 10:22 AM on December 10, 2023
This is generally not a great idea from an efficiency standpoint though, as having as much of your chimney inside the heated building envelope means you get as much heat a possible out of it. The more of it you put outside, the more heat you lose.
Expect to spend a few thousand, assuming you're dealing with a single story.
Sounds like your plumbing vent needs bracing or perhaps relocating nearer the peak of the roof, if possible, assuming you're dealing with a roof that sheds snow and the vent is near the eave.
posted by ssg at 10:22 AM on December 10, 2023
Regarding your thought of creating a green roof, this is MAJOR construction. The earth/growing mix/plants are extremely heavy, and you need to add membranes to the existing roof to prevent leaking. You can't just add earth to your roof and plant grasses. Installing will require a lot of research and planning. I would suggest finding someone who installs them and picking their brains for practical information.
For your leaking roof, it may be as simple as fixing or replacing the flashing around the chimney. I hear you about your older age and the risks of climbing on roofs. As an ICU nurse I took care of a number of people who fell off ladders or roofs, and not all of them survived. You are wise to outsource roofwork!
Is there any kind of trade school/union training in your area? You might be able to work with them to use their students (with supervision) to perform the repairs necessary at a reduced cost. In some locations there are programs in place to assist seniors with home repairs, so that might be another thing to investigate. Contacting your local elected officials would be a good place to start, as most state representatives/congresspeople have excellent staffs charged with constituent support who are familiar with resources and programs you may qualify for. Good luck!
posted by citygirl at 12:03 PM on December 10, 2023 [5 favorites]
For your leaking roof, it may be as simple as fixing or replacing the flashing around the chimney. I hear you about your older age and the risks of climbing on roofs. As an ICU nurse I took care of a number of people who fell off ladders or roofs, and not all of them survived. You are wise to outsource roofwork!
Is there any kind of trade school/union training in your area? You might be able to work with them to use their students (with supervision) to perform the repairs necessary at a reduced cost. In some locations there are programs in place to assist seniors with home repairs, so that might be another thing to investigate. Contacting your local elected officials would be a good place to start, as most state representatives/congresspeople have excellent staffs charged with constituent support who are familiar with resources and programs you may qualify for. Good luck!
posted by citygirl at 12:03 PM on December 10, 2023 [5 favorites]
For both the chimney and the water vent, it's definitely possible to have them exit the attic space through a wall rather than the roof itself. However, both will still need to be higher than the highest point on your roof, so doing this may not do anything to solve your problem. They may not be subject to as much side-loading from snow slipping down the roof, I guess, but they'll have to be close to the edge of the roof and would likely get caught up in snow on the roof if it's substantial enough. Going horizontally for a short distance wouldn't be a problem, but I would put as much slope in the section inside the roof as possible if I were to go down this path (which I wouldn't recommend).
As ssg suggests, I would move the vent as close as possible to the peak of the roof to minimise the amount of snow above it and ensure it's well-braced. The same applies to the chimney (assuming it's a metal tube, not a brick chimney). If you're replacing the roof anyway, this shouldn't cost much.
A green roof is a whole other thing and, noting you didn't explicitly ask, a lot more information would be needed to give you any advice on that.
posted by dg at 2:22 PM on December 10, 2023
As ssg suggests, I would move the vent as close as possible to the peak of the roof to minimise the amount of snow above it and ensure it's well-braced. The same applies to the chimney (assuming it's a metal tube, not a brick chimney). If you're replacing the roof anyway, this shouldn't cost much.
A green roof is a whole other thing and, noting you didn't explicitly ask, a lot more information would be needed to give you any advice on that.
posted by dg at 2:22 PM on December 10, 2023
Some plumbing can be vented inside the house - my washing machine is since plumbing vents weren't required for washing machines when my house was built, and adding one was way more expensive. IMO their need is somewhat overstated (i can tell no difference in my laundry room having one vs not having one) and I've never been up on the roof (and only seen a plumber use one once) to use it for a cleanout location.
As for your green roof idea, if budget is a concern, think again. Green roofs are expensive in terms of design and maintenance compared to a regular roof. They are generally not even economical for commercial properties.
posted by The_Vegetables at 7:27 AM on December 11, 2023
As for your green roof idea, if budget is a concern, think again. Green roofs are expensive in terms of design and maintenance compared to a regular roof. They are generally not even economical for commercial properties.
posted by The_Vegetables at 7:27 AM on December 11, 2023
What is the prevailing code in your jurisdiction?
Per the Uniform Plumbing Code, vents shall extend vertically at least 6" above the roof. (Random aside: in a snowy area you also need a minimum 2" vent for snow closure reasons.) So no side venting under the UPC.
I'm confused why your vent is "falling over". How tall is it? What material is it made of? How is it flashed to the roof?
If you've got it run 6' tall or something, I'll mention that vents aren't permitted to be flagpoled unless the roof is an assembly area, as in a large building with a rooftop community space or something. This doesn't sound like your situation.
The point of venting is to (1) protect your trap seals and (2) safely "dispose" of any sewer gases to atmosphere. Plumbing is never, ever vented inside the house. That would imply you're allowing sewer gases to freely flow into your home. It sounds like The_Vegetables has an air admittance valve, or "Studor vent". This allows air *into* the pipes to protect your trap seals under a negative pressure condition, and seals shut under a positive pressure condition. An AAV will vent an individual fixture, not an entire house. The AAV is supposed to protect the trap seal, but... they are not impressively reliable.
Regardless, venting your entire guest house with AAVs is not going to be feasible/legal under the UPC for several reasons. First, you are required to have at equal or greater aggregate cross sectional area of vents through the roof as the largest required building sewer, in order to safely vent the sewer itself. This applies to both houses with public sewer connections and those with private sewage disposal systems like septic. For example, if you have a 3" diameter sewer, you need 7.06 sq inch of vent through the roof (one 3" vent, two 2" vents plus a 1.5" vent, etc). Having no vent through the roof all means zero cross-sectional area; this isn't going to fly. Secone, AAVs aren't allowed under the UPC (although some jurisdictions permit them under an amendment for certain conditions).
Separately from legality, I don't love air admittance valves as a venting alternative. They tend to fail over time, and then you have sewer gases in your home until you fix it or get a new one. Or they fail intermittently due to fluctuating temperatures and pressures, which means you intermittently have toxic and explosive gases in your home. For that reason I especially wouldn't recommend them in a property you're not using on a daily basis, because the problem could start when no one is using the property and develop into a very unsanitary condition, not to mention sewer gases are very flammable.
Happy to answer more questions, and definitely curious why specifically the vent is falling over since that is unusual.
Source: I am a licensed plumber with experience working on construction projects with values up to $50 million on the plumbing contract.
posted by cnidaria at 8:05 AM on December 11, 2023 [1 favorite]
Per the Uniform Plumbing Code, vents shall extend vertically at least 6" above the roof. (Random aside: in a snowy area you also need a minimum 2" vent for snow closure reasons.) So no side venting under the UPC.
I'm confused why your vent is "falling over". How tall is it? What material is it made of? How is it flashed to the roof?
If you've got it run 6' tall or something, I'll mention that vents aren't permitted to be flagpoled unless the roof is an assembly area, as in a large building with a rooftop community space or something. This doesn't sound like your situation.
The point of venting is to (1) protect your trap seals and (2) safely "dispose" of any sewer gases to atmosphere. Plumbing is never, ever vented inside the house. That would imply you're allowing sewer gases to freely flow into your home. It sounds like The_Vegetables has an air admittance valve, or "Studor vent". This allows air *into* the pipes to protect your trap seals under a negative pressure condition, and seals shut under a positive pressure condition. An AAV will vent an individual fixture, not an entire house. The AAV is supposed to protect the trap seal, but... they are not impressively reliable.
Regardless, venting your entire guest house with AAVs is not going to be feasible/legal under the UPC for several reasons. First, you are required to have at equal or greater aggregate cross sectional area of vents through the roof as the largest required building sewer, in order to safely vent the sewer itself. This applies to both houses with public sewer connections and those with private sewage disposal systems like septic. For example, if you have a 3" diameter sewer, you need 7.06 sq inch of vent through the roof (one 3" vent, two 2" vents plus a 1.5" vent, etc). Having no vent through the roof all means zero cross-sectional area; this isn't going to fly. Secone, AAVs aren't allowed under the UPC (although some jurisdictions permit them under an amendment for certain conditions).
Separately from legality, I don't love air admittance valves as a venting alternative. They tend to fail over time, and then you have sewer gases in your home until you fix it or get a new one. Or they fail intermittently due to fluctuating temperatures and pressures, which means you intermittently have toxic and explosive gases in your home. For that reason I especially wouldn't recommend them in a property you're not using on a daily basis, because the problem could start when no one is using the property and develop into a very unsanitary condition, not to mention sewer gases are very flammable.
Happy to answer more questions, and definitely curious why specifically the vent is falling over since that is unusual.
Source: I am a licensed plumber with experience working on construction projects with values up to $50 million on the plumbing contract.
posted by cnidaria at 8:05 AM on December 11, 2023 [1 favorite]
Regardless, venting your entire guest house with AAVs is not going to be feasible/legal under the UPC for several reasons.
I don't think the OP implies or assumes that his home just has one plumbing vent. AAVs are fine for a line or two, and sewer gas is very noticeable if they fail. I've actually heard of a sewer gas explosion - they occasionally occur in underground telecom vaults where there is no venting - so you should not go in there without adding air first. But in a home? They are extremely rare.
To your point though, PVC plumbing vents are very strong, so one getting 'knocked over' seems like a fixable problem.
posted by The_Vegetables at 7:17 AM on December 12, 2023
I don't think the OP implies or assumes that his home just has one plumbing vent. AAVs are fine for a line or two, and sewer gas is very noticeable if they fail. I've actually heard of a sewer gas explosion - they occasionally occur in underground telecom vaults where there is no venting - so you should not go in there without adding air first. But in a home? They are extremely rare.
To your point though, PVC plumbing vents are very strong, so one getting 'knocked over' seems like a fixable problem.
posted by The_Vegetables at 7:17 AM on December 12, 2023
The_Vegetables, my impression is that it's a small guesthouse and they want to remove the single VTR that serves the bathroom/kitchen wet wall (multiple fixture vents are often connected together in the wall into a single vertical vent through roof, or VTR).
It's possible that my assumption is mistaken and they have multiple VTRs and only one is falling over.
AAVs are still code violations in many jurisdictions, and for good reason. They fail and it stinks. Literally.
posted by cnidaria at 6:02 PM on December 15, 2023
It's possible that my assumption is mistaken and they have multiple VTRs and only one is falling over.
AAVs are still code violations in many jurisdictions, and for good reason. They fail and it stinks. Literally.
posted by cnidaria at 6:02 PM on December 15, 2023
Also, sewer gas is only noticeable if *you use the property*. If you're leaving it unused and only going in there sporadically when you have guests, you won't notice the problem when it's sitting unused.
posted by cnidaria at 6:07 PM on December 15, 2023
posted by cnidaria at 6:07 PM on December 15, 2023
(Ask anybody who's come back to a disused vacation home to find their water closet p-trap evaporated and the house full of sewer gas. Mineral oil is a common preventative solution in those long vacancy situations.)
posted by cnidaria at 6:09 PM on December 15, 2023
posted by cnidaria at 6:09 PM on December 15, 2023
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posted by armoir from antproof case at 9:32 AM on December 10, 2023 [2 favorites]