Toilet Vent Pipe, Right thtrough the Roof?

[k1hog]

I ordered the black water tank today, only time will tell how that is going to turn out.

Question, the 1and 1/2 inch vent pipe must go through the roof of the cargo trailer, Please tell me how
you dealt with this? Did you back up the thin metal roof with something, and how did you seal the hole?

Thanks

Johnnie

[pete42]

my first double post darn..............sorry

[pete42]

does it have too go through the roof or it should go through the roof?

the reason I ask is that the black water tank was vented on the side of my scamp higher than the toilet of course.
the toilet was one where the toilet sat on top of the black water tank kinda like a big porta-potty
but the tank was emptied through the bottom with a regular dump valve arrangement.
one advantage of the vent on the side of the trailer was that the vent exit could be modified to be removable
and a water hose could be inserted allowing the holding tank to be flushed with out having to drag a hose into the camper.

if you want to vent it through the roof take a look at some travel trailers and see how they were done.
be sure and seal it at the tank and make sure it does not settle into the tank there have been cases where the vent
pipe has slid down into the tank which causes all kinds of trouble.

pete

[k1hog]

I am not sure that the vent pipe MUST go through the roof, but all the rv's I have seen that was how it was. Could be something to do with managing the order. I have read the pipe must be atleast 2" above the roof with a vent cap or one of those new whirley vent caps.

In my mind it seems that must be something to stiffen up the metal roof?

Thanks

Johnnie

[Engineer Guy]

The Vent 'trick' on my 2 TTTs is for the PVC Vent Pipe to be very rigid mechanically; held in place well [with Clamps, etc.]. Then, the Roof has 'nothing' to with the function of Pipe support; it's just something the Pipe passes through.

When re-sealing my Roof, I noted that the seal around the Vent Pipe ['Stack'] is simply sealed well; no magic to it. The usual friction-fit Cap placed on top [often held on with a Sheet Metal-type Screw] is larger-enough diameter that it prevents Water coming straight down from getting near the Vent Pipe. This is also one reason the Vent Pipe terminates above the Roof by only 2" or so. The closer the top Cap sits to the Roof within reason, the better job it does of shielding the through-Roof penetration. I've also seen TTs with no Cap; just the blunt cut PVC Pipe.

A TTT Pal has a lil top Vent Propeller I bought him, and likes it. I haven't gotten around to installing mine yet.

From living in a Trailer during House Construction, I can testify that smell outside can be an issue. In my Mind, this is one reason to extend the Vent Pipe through the Roof vs. the side; to get improved draw from higher pressure differential. The claim of the lil Vent Propellers is help exhaust smells away from the Trailer in a breeze, or during Travel.

The same good clamping advised above prevents the PVC Vent Pipe from sliding down into the Black Water Tank. A good bead of RTV Silicon Sealant, or the Sealant advised by the Tank Manufacturer, will do the trick at the Tank top of sealing the Vent Pipe connection.

[closurdo]

All you need is the plumbing vent cap kit http://www.campingworld.com/shopping/item/replace-all-plumbing-vent-kit-polar-white/35181 secured correctly to the roof.
The hole around the pipe itself can be a little larger that the vent pipe because the design of the vent cap keeps it from leaking. As stated in the above post the vent pipe should protrude through the roof by about 2". If you have a small mom and pop rv/camp store in your area you may be able to find a metal vent pipe cap kit instead of the plastic one that campingworld sells.

[pete42]

I too would vote for a vent in the roof for all the reasons stated above I was just letting you know how others have been done before.

they make a weather-vane looking cover that "pulls" the oder up and out the pipe Others have told me they like them

On travel trailers I have owned the pipe just stuck up in the air with a plastic cap, the plastic cap does weather and needs replaced after a couple of years.

let us know what you decide

pete

[8ball_99]

All you need is the plumbing vent cap kit http://www.campingworld.com/shopping/item/replace-all-plumbing-vent-kit-polar-white/35181 secured correctly to the roof.
The hole around the pipe itself can be a little larger that the vent pipe because the design of the vent cap keeps it from leaking. As stated in the above post the vent pipe should protrude through the roof by about 2". If you have a small mom and pop rv/camp store in your area you may be able to find a metal vent pipe cap kit instead of the plastic one that campingworld sells.

What he said.. If the cap is installed right with putty tape it won't leak... You want the vent on the roof cause poo stinks.. Ever been on the roof of your house and got close to one of your plumbing vents? It doesn't smell good.. Same idea with a black water tank on a trailer.. You dont want the vent down low, You want it up above in the air.