Need mobile home ventilation advice asap

[Dertman]

Hello,

We have been doing a total remodel of an older single wide on my wife's families land. Everything has been good up to the master bathroom. I tore out the old tub and shower. I have a stand alone soak tub to install but the vent pipe is above the sub floor outside the wall. Every sink in the trailer is ventilated. If I were to plumb the tub drain straight down would I need a vent for the tub since all the other drains in the mobile home are vented? Would save me a lot of time if I didn't need to vent that tub drain.

Thanks

 

[WorthFlorida]

How far is the nearest sink vent pipe from the tub? It can be up to 8' for a 2" drain, 6" for a 1.5" drain.

In new construction, the simplest way to vent a bathroom group is usually to install a single vertical vent pipe behind the bathroom sink. This works as long as all the plumbing fixtures connect to the main drain line in the floor within 8 lineal feet of the sink drain.

 

[Sponsor]

 

[Dertman]

How far is the nearest sink vent pipe from the tub? It can be up to 8' for a 2" drain, 6" for a 1.5" drain.

In new construction, the simplest way to vent a bathroom group is usually to install a single vertical vent pipe behind the bathroom sink. This works as long as all the plumbing fixtures connect to the main drain line in the floor within 8 lineal feet of the sink drain.

View attachment 77783

The sink is definitely less than 8 feet away from the bathtub. And like I said they all have those under the sink check valves. So it would be ok to forgo putting one in the bathtub?

 

[Reach4]

The tub needs a trap. The tub would down to the input of the trap. The output of that trap needs to stay horizontal for 3 or more inches if that is a 1-1/2 inch trap. Then it join the lavatory drainage, which wet-vents the trap. After that, the drainage can go straight down etc.

 

[Dertman]

So I don't need to redo the check vent that is above the sub flooring.. that's my main concern

 

[WorthFlorida]

Check Vent? Do you mean an AAV (air admittance valve)? It doesn't hurt to leave it. Is this sink the bathroom sink with presently an AAV or a roof vent?

 

[Dertman]

Check Vent? Do you mean an AAV (air admittance valve)? It doesn't hurt to leave it. Is this sink the bathroom sink with presently an AAV or a roof vent?

It's a mobile home so all the vents are under the sink, like those little black cap vents I've seen them called cheater vents. Honestly I'm not sure if there's a vent on the roof.