Old mobile home plumbing; lack of vents

[ImOld]

Do they have different rules for mobile homes?

I am doing an "everything" remodel for a friend on an older home. Putting aside the other trade anomalies, I don't see how the plumbing can be done to code considering all the interior walls are only 1.5 inches thick.

I did have training working for my grandfather the plumber back in the 1950's during summer vacations. You haven't lived until you let loose a few hundred pounds of lead pipe from an upper floor. But I digress!

I might add that there are no reported problems with the plumbing system nor do I see any sign of any. It is just "different".

 

[Terry]

They don't really have codes for those.

I had a double wide when I was younger, and my parents had a double on the ranch and a single on the farm.

In the picture above, the correct solution would be to add an AAV to prevent siphoning of the trap. If you look on the roof, there should be at least on 3" pipe through the roof for venting. That single vent does not take care of all the fixtures.
Without the venting on the individual fixtures, your sinks will still drain, but they also siphon the traps dry. The Master bath in my parents double wide smelled pretty bad because of this.

 

[Sponsor]

 

[ImOld]

Thanks for the quick reply Terry.

I guess I'll just play it by ear.

The kitchen sink doesn't even have a trap! Straight on down to the main drain.

The dishwasher goes straight into this line also.

And it all works without a hitch or any venting.

There are two vents in the bath area which contains all the plumbing for the toilet, tub, sink and washer.

I can't see how they are run but as I said, there are no smells, overflows, slow drains, etc.

Since everything is and has been working, I guess I'll go with the flow. Pun intended!

If it ain't broke, don't fix it!

 

[Jadnashua]

Vents don't necessarily improve emptying a sink...they keep adjacent traps from getting siphoned dry. The traps are what block the smells, sewer flies, sewer gasses, etc. from getting into the house from the pipes. An s-trap often drains TOO well, and siphons its own trap dry.

 

[Gary Swart]

You may already know this, but the trap you show in the photo is an illegal S trap. The vent, AAV or otherwise, must be install before the drain goes down into the floor. Good news is, there appears to be plenty of space to do the AAV.

 

[Tom Sawyer]

The DWV piping in mobile homes is usually so undersized, and poorly pitched that putting aav's on is a waste of time. The drains won't evacuate fast enough to pull the trap.

 

[ImOld]

Thank you all for your comments.

Yes, I'm aware of all that has been mentioned.

I will gingerly address these "technical" problems.

I say this because I spent my life as a field engineer and you learn not to mess with, what the customer views, as a working system.

"It worked perfectly for years until you touched it".

 

[Gary Swart]

I have very, very limited experience with mobile home plumbing, but from those few I have seen, it looks to me like replacing the drain plumbing to meet codes would not be an extremely difficult nor expensive job. Everything is underneath the floor. Vent might take some creativity with the thin wall thickness, but not impossible. Vents can be on the exterior you know. Like virtually any remodeling job, there are lots of things that are not in the books and require some inventive thought. I'm not suggesting that codes be forgotten about in this process.

 

[Terry]

Gary,
I'm thinking more like you, but then on the other hand, it is a mobile home.
If it was sold that way, and they bought it, it must be okay.

We couldn't do stuff like that on an inspected home, but then this will never, ever, be looked at by anyone resembling a person in authority or of knowledge.
It is what it is. A little more than a shack, and less than a home.
I've lived in one, it was pretty basic. My parents had a couple on their extra properties.
Heck, even the log cabins in Canada didn't have much when it came to plumbing. The sink on the Quesnel Lake Cabin daylighted in the sand outside. No septic.
We did have a nice outhouse though. We even dug a new hole, moved the outhouse to the new hole and then re-roofed it.
Having the bear watch while you were using it was a bit strange. All we had was a shower curtain for a screen.

My brother Shannon in the 70's

 

[Gary Swart]

Well Terry, glad I wasn't too far off on my thinking. My wife knows we're in for mess when I utter the words, "Where's my crowbar", because I'm about ready to tear out something. I have always hated to make do with anything sub par. Not to mention that is really easy to suggest spending other peoples money!

 

[ImOld]

I know this hurts you guys in the trade and I won't bother you any more on this mobile home.

I can't let this slide. It's all toast. Replace everything you see.

There actually is an AAV in there.

In case you don't notice, the dishwasher discharge is just sitting in an open fitting!

And there are a couple of slip joints held together with the " handyman's secret weapon".