Toilet Mystery! Can you solve it?

[N80]

Bird, I think the intended, or at least accepted, use for a Studor vent is in places like a free-standing kitchen island where running a vent pipe upward is not an option. I'm assuming, based on what I've learned over the last 4 years is that they are not intended to vent a whole house, especially not through one Studor valve. And for the record, I have a one on each vent stack and have not routed all of the vents through one Studor valve.

And also, for clarification, the toilet problem I had is not really related to my system set up. That problem occurred because a part that should not fail, failed. The flaw in my system has nothing to do with how well it vents the tub, toilet and sink. It does that extremely well. In fact, when I finished plumbing this system I filled the bathtub and both sinks with water. Then I unstopped them all at once and flushed the toilet at the same time. All fixtures drained perfectly.

The flaw is that as the system is configured, there is nowhere for septic gases to vent back out. In a normal system they vent back out the open vent pipe on the roof. So at least in theory the gasses that build up in my septic tank have nowhere to go since the Studor vent allows air in but not out. What this typically does is cause septic gasses to vent up through the toilet and sink traps into the house. A smelly and potentially dangerous situation. However, we have never smelled septic gasses in the cabin. Never. However, the cabin gets weekend use by no more than four occupants so septic gas buildup is probably very very light.

Regardless, its a flawed system and I intend to correct it.....as soon as I get a roundtoit.

MrJimi, I'm a Nikon nut. I think I own four now. I used to moderate on a very large, successful Nikon web site. Love my Nikon gear. I'm sure the competitors make good stuff too and I'm really not a 'brand loyalty wacko. But when I get stuff and it lasts and works the way it is supposed to, I stick with it.

 

[Redbug]

One thing also about the toilet (drain) line that goes under the house from the toilet to the septic tank...the slope is also important. Too flat of a slope will allow the liquids to drain too fast, leaving the solids behind, in the pipe. I don't think too much slope is much of a problem, though, (not sure).

That's what I was thinking when reading your symptoms in your first post, George. I'm glad you decided to vent, (ha ha), your results. I learned something new!

 

[kenmac]

B-4 you mention the studor vent (cap) & (b-4 you told what was wrong)I was going to suggest check for obstructed vent. .Studor vents are legal ( at least here) you just aren't allowed to close them in ( where you can't get to them). I have checked plumbing with with the same problems that you had & it was also studor vent that cause the problem. For some reason the check valve/ball sticks after a period of time. I have used studor vents when adding a bathroom to existing home where the the roof is very steep

 

[N80]

B-4 you mention the studor vent (cap) & (b-4 you told what was wrong)I was going to suggest check for obstructed vent. .Studor vents are legal ( at least here) you just aren't allowed to close them in ( where you can't get to them). I have checked plumbing with with the same problems that you had & it was also studor vent that cause the problem. For some reason the check valve/ball sticks after a period of time. I have used studor vents when adding a bathroom to existing home where the the roof is very steep

That is very interesting. So apparently there are a number of legitimate ways to use them. Again, I see no problem with then whatsoever as long as 1) they function properly and 2) there is some point in the system at which the septic tank can vent outward.

Dave, the slope of the main line is very important. That was one of the main things I had to figure out in my system. I only had so much depth to work with (the floor to the ground under the house) and the distance from the toilet to the exit point is also fixed. Because of this you have to be careful about how far your DW assembly comes down. In any case, after much calculating I think I did get that right. And there is a potential problem with too much slope too. If it is too steep the speed of the water will exceed that of the solids and the solids get left behind in the pipe.

 

[mikim]

The optimum slope on a septic line is 1/4" per ft (2.5" per 10' pipe) -- you can vary a little bit from that and it'll still work - just not as well. Your vent being plugged was one of my first thoughts ...not because I'm so bloody smart ...but because of the "btdt" rule. In my case it was a vent pipe on an old mobile home that was plugged by a bunch of leaves and was only 2" to start with. I'm afraid it took me longer than 2hrs to figure it out ....BUT I never forgot it! Now I make darn sure about those things. You CAN do the roof .... it's only scary that's all....it's not hard. H__ I did it! You can do it too. I knew about those studor vents - but only ever thought of them in an under the sink application.......Go to the box store and take a look at one of those lead vent caps. You'll see how soft and pliable they are and how they'll form to your roof. They have a "skirt" (lack of a better term) around them and I sealed around it with mobile home roofing tar. I promise you - it'll work and you can do it.

 

[riptides]

(Now, this Studor vent system is pretty unconventional but it passed inspection and we've had no problems with septic gases in the house or attic. We've discussed before that this is not an ideal set-up and after this I'll probably put the main vent stack through the metal roof, just to avoid a similar failure in the future. I'm sure the roof will leak at this point the first time it rains. )

When we put our metal roof back on, we vented accordingly. Experience and all that.....

And it has not leaked yet.


Could you have run it out the side?

-Mike Z.

 

[Erik_in_Hoyt]

IRC - which is one of the 2 national building codes in current use - allows venting out the side of a wall so long as it's not anywhere near a vented soffitt and is at least 2' below the eaves. The other thing I'd look at doing is put a vent somewhere near your septic tank that lets air out but not in. Also - around here they sell things called AAV's which sound a lot like your studor vent. (check the lowe's or home despot websites for information about them)

good luck!

 

[N80]

IRC - which is one of the 2 national building codes in current use - allows venting out the side of a wall so long as it's not anywhere near a vented soffitt and is at least 2' below the eaves.

I've been thinking about this. The problem is that the vent stack is in an interior wall. This will make it hard to run it to a side wall (now that the walls are all finished). Also this would have put the vent coming out on the back of the cabin, which is the side you drive up to and I think this would be a little ugly (my wife might not like it). The soffitt is also vented on this side of the cabin.

The other thing I'd look at doing is put a vent somewhere near your septic tank that lets air out but not in.

This is what I'm thinking about now. I could tap into the PVC septic line just as it exits the house. I could run a 2 or 3 inch PVC pipe up the end wall of the cabin from this point which would allow venting of septic gasses. The soffitts are not vented on this side of the house. I could paint the pipe brown to match the cabin. Is there a valve that allows air out but not in (which is the opposite of a Studor vent)? I think this would be perfect. The only problem would be tapping into the PVC septic line as it exits the house. I'm not sure how this can be done. I guess I could just drill a hole into the line the same diameter as the vent pipe I would use. Which would make a 2" line the best. Then just use PVC pipe cement to 'bond' it. Maybe caulk around that?

 

[AlanB]

I've been thinking about this. The problem is that the vent stack is in an interior wall. This will make it hard to run it to a side wall (now that the walls are all finished). Also this would have put the vent coming out on the back of the cabin, which is the side you drive up to and I think this would be a little ugly (my wife might not like it). The soffitt is also vented on this side of the cabin.



This is what I'm thinking about now. I could tap into the PVC septic line just as it exits the house. I could run a 2 or 3 inch PVC pipe up the end wall of the cabin from this point which would allow venting of septic gasses. The soffitts are not vented on this side of the house. I could paint the pipe brown to match the cabin. Is there a valve that allows air out but not in (which is the opposite of a Studor vent)? I think this would be perfect. The only problem would be tapping into the PVC septic line as it exits the house. I'm not sure how this can be done. I guess I could just drill a hole into the line the same diameter as the vent pipe I would use. Which would make a 2" line the best. Then just use PVC pipe cement to 'bond' it. Maybe caulk around that?

I dont think you would need the valve if you were straight into the line, as it would just be a standard vent at that point, and they have no valves. That said, depending on the valve design, you may be able to plumb or rework a valve to work in "reverse" They are really fairly simple.

You will need a saddle to plug in the T on the drainline if you go that way. Very common at whatever supply house you like using.

 

[EddieWalker]

Cutting the hole in the metal roof and sealing the vent line is pretty simple to do. The metal roof makes it allot easier then doing it on a shingled roof.

Line up from the inside where the pipe needs to go through the roof. Drill a pilot hole on the line and then use a saber saw or sawzall with a metal blade to cut it out. If you don't have the room for the say, then drill a few holes around the circle and cut from the top. Don't worry if it's not a perfect cut, none of them ever are.

The trick here is the hole you cut in your seal. The rubber has rings around it so that you can cut it in a circle and not mess it up. Decide how big the outside of your pipe is and cut the seal out one size smaller. You can go two sizes smaller is you like and cut some more if you can't get it to fit. If it's too loose, it's garbage and you need to buy a new one. You slide the seal over the pipe and down onto the roof. It has to be as tight as you can get it to make it water proof.

Make sure you get the lead type as Mike mentioned. It will mold to fit the contour of your roof panel so that it doesn't matter where the hole is.

I use the most expensive silicone available to seal it. Just coat the bottom of the seal as thick as possible and put into place. Then screw through the metal around the edge of the seal into your roof. The silicone will ooze out and make a big mess when it's tight. Clean up the silicone and you have a water tight seal.

It's an easy job, just don't do it on a hot day or when the metal has any moisture on it. I'm sure you already know how slippery a metal roof can be when it's wet!!!!

For toilet to vent properly, there really isn't anything that does the job as well as a direct vent through the ceiling. You can get away with some stuff on the other vents, but not toilets.

Eddie