Ask Me Help Desk - Venting macerating pump from basement

Venting macerating pump from basement

Hi.

This is my first post!

I have searched around and learned a lot about macerating pump systems and how to install them and whatnot.

I have a situation where I want to install one of these in my basement. I have a great place for discharge, but I do not have anywhere to vent it. I know I am supposed to vent this to 2-way open air (no cheater valves) that eventually reaches to 6" above the roof line and certain distances away from the property line, etc (according to what is likely my local code).

My questions are:

(1) I read on some forums that someone vented the pump ALSO to the main sewage line that the exhaust was going to, creating a sort-of circular flow. As exhaust was expelled, air intake was happening. This was supposedly OK, at least back in time when this was written. Is this OK to do? Seems like this may have been permitted at one time but maybe not today? Also seems like a not-so-good-idea, in general.

(2) My main stack is way far away. Like 40 feet away, maybe. Could I run a horizontal vent pipe all this way and tap into the main stack, and if I do does it have to tap into the main stack HIGHER than the highest drain attachment is on it? It seems logical that this would have to be the case, since there could be a chance where sewage from a higher toilet could be falling at the same time as the pump is sucking in air, in which case it might suck in some sewage too. Yuck.

(3) What possible options do I have other than to tear apart the house and install a standalone pure vent stack ALL the way up to the roof? (I haven't ruled this out yet but looking for an easier way). Local codes say I can't install the vent on the outside of the house (I wouldn't want to do that anyway).

(4) Are there any vent-free macerating pumps? I seem to think that Saniflo had one but was only for a toilet and nothing more (I am looking at installing a toilet, sink, and shower stall).

Thank you in advance for your time. I will continue to research while I eagerly await any responses. I have performed considerably involved home projects and the biggest hurdle I generally have is learning the common terms and definitions that people tend to use, and understanding that people interchange these terms often and how to recognize and translate that. Once I get past that I am pretty much good to go.

.. dan

Dan, if you are talking about installing a bathroom group (toilet, sink and shower) then you will ABSOLUTELY require plumbing vents to start. Here, you may be able to WET VENT the bathroom group, but even that still requires a minimum 2" vent for the group (2" sink drain and 2" sink vent act to vent entire group). With that being said, the saniflo macerator pump will allow you to connect the macerator pump vent into the plumbing vent from the bathroom group. The installation manual is great and has clear drawings to show all this.

Glad to discuss more if you like...

Mark

Hi!

Thanks for the response!

I did look at the manual and it shows clearly how to hook up a bathroom group (toilet, sink, shower) into one vent. That's pretty easy and obvious. The hard part is finding a place to vent all of this to.

I have heard of a WET VENT but don't quite understand what that means. I am guessing that could mean to, for example, vent to my main stack BELOW one or more other plumbed items at the above floors. That would suggest to me that at the time an upstairs toilet is flushing, the macerating pump downstairs could be sucking in air, and potentially suck in some sewage with it?

If this is the correct definition of WET VENT, could I alternatively WET VENT to my main 3" drain LINE (the 3" pipe that runs horizontally across my whole basement)? This would be similar to what I described in (1) in the original post.

Nope, can't do what you are suggesting.

Wet venting is when the 2" SINK DRAIN and 2" SINK VENT act to vent the toilet and shower. Here, the 2" sink drain connects into the 3" (or 4") toilet drain (fitting rolled above the centerline of the toilet drain) and the shower drain connects into the sink drain...2" sink vent vents the entire group.

The 2" wet vent (sink vent) goes off and connects to a vent that is 6" higher than the flood level rim of the bathroom sink (or kitchen sink) on the first floor IF no other fixtures connect into the stack above that. Otherwise, you run this 2" vent from the basement up and into the attic where you can connect it into a 2" or larger pipe in the attic (or go out the roof separately).

A vent can always be tucked into a closet and hidden that way to get into the attic if needed.

Tom, he isn't talking about a sewage ejector...he's talking about a macerator pump system...totally different puppy here as this macerator's pump vent can tie back into the plumbing vent system right in the bathroom.

Thanks Did you get my PM? Tom

No Tom...no PM received here...please resend!

Mark

Ok.

Thanks for the information!

From this I conclude that I simply need to run a new vent from the basement all the way to the roof. There are no other "future vents" in the basement.

The most convenient way I can see to do this is to run a vent straight up vertically from the pump about 6 or 7 feet, then horizontally 51 feet (yes, that's fifty-one feet!) with a couple 90 degree turns in there, then up through the first floor to the attic above the garage where I can tap into an exposed existing vent line, which I believe to be 6" above the highest flood plane up there on the second floor (if that makes a difference).

Under NY codes (which is under IPC) can I even do this, assuming of course I maintain a 1/4" per foot slope back down towards the pump? Would I need an enormously crazy large diameter pipe?

Quote:

Originally Posted by massplumber2008

Tom, he isn't talking about a sewage ejector...he's talking about a macerator pump system...totally different puppy here as this macerator's pump vent can tie back into the plumbing vent system right in the bathroom.

Yes, that's correct. A macerating pump, something like a Saniflo or a "Bathroom Anywhere".

Read post #5 above...

Hi!

I guess I'm asking if there are any restrictions on the horizontal/vertical run lengths before I can get to 6" above the highest flood level. I read on other sites about horizontal run limits for certain sized pipes, but the certainty wasn't clear. Another site said the horizontal runs cannot exceed 20% of the total run (which doesn't sound right to me).

<<The 2" wet vent (sink vent) goes off and connects to a vent that is 6" higher than the flood level rim of the bathroom sink (or kitchen sink) on the first floor IF no other fixtures connect into the stack above that. Otherwise, you run this 2" vent from the basement up and into the attic where you can connect it into a 2" or larger pipe in the attic (or go out the roof separately).>>

The most common restriction in venting is that the horizontal pipe cannot exceed 33% of the total developed length of the vent which means, for example, that a 100 foot run of vent pipe cannot exceed a 33 foot run of horizontal pipe in the basement. If you do exceed this length then you would increase the pipe to 2.5" (not readily available) or 3" (readily available) PVC and then the restriction is MOOT!!

Back to you...

Ok, thanks!

Hmm. It would be really tough to route a 3" pipe all the way to where I need it to go. My walls aren't thick enough. I suppose I could increase the EFFECTIVE volume "up one pipe size" by routing two 2" pipes side-by-side.

I don't otherwise see an easy or even moderately difficult solution without blowing through and demolishing two stories to get to the roof.

I think my choices are (1) scrap the whole idea and just go watch TV or (2) choose a macerating pump/toilet that does not require a vent (http://www.saniflo.com/product-details-for-sanicompact).

Quote:

Originally Posted by massplumber2008

The most common restriction in venting is that the horizontal pipe cannot exceed 33% of the total developed length of the vent which means, for example, that a 100 foot run of vent pipe cannot exceed a 33 foot run of horizontal pipe in the basement. If you do exceed this length then you would increase the pipe to 2.5" (not readily available) or 3" (readily available) PVC and then the restriction is MOOT!!

Back to you...

Just how far horizontally do you need to run the vent and how far do you need to run the vent vertically. It is very rare that the horizontal vent exceeds the 33% rule...??

I can go about 7' vertically from the pump, then about 50' (fifty feet) horizontally (from one dead end of the house to the other with a couple of turns in there), then up another 10' or 12' until I can tap into an existing dry vent (although it is only 1.5"... I guess it should be 2"). If I don't tap into that vent, another 10' or so until I poke a hole in the roof.

So I guess 50' total horizontal, 20' to 30' vertical.

The next thought is to skip the macerating pump and go old-school, bust through 23' of concrete, lay 4" pipe to the main line for drainage, and go with an AAV to vent the group (which I believe is allowed under NY/IPC).

Quote:

Originally Posted by massplumber2008

Just how far horizontally do you need to run the vent and how far do you need to run the vent vertically. It is very rare that the horizontal vent exceeds the 33% rule...??