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Inland RV Center, In · 03-26-2009, 11:21 AM

Quote:

Originally Posted by polarlyse

Is it necessary to climb onto the roof to replace the sewer vent gasket or can it be done while reaching from a ladder ????? If you must climb onto the roof what precautions must be taken to avoid damage ???? Plan on doing this job soon and of course will probably find other locations that need to be re-sealed or repaired.

Thanks for any advise

Roger Kriz
kriz@rci.rutgers.edu

The sewer vent pipe covers can be reached from a ladder.

Andy

Utahgoldrup · 03-26-2009, 04:00 PM

Thanks Bob! I have my vent seals ordered and once I have them, will use acrylclean and a plastic scraper like you mentioned to get the goop off. What is the process on putting the new seals on? Do you put any sealent down first or just put the gasket down, vent cover on top, screw it down and then put sealent around the vent pipe cover? I just want to make sure I put it all back the right way so I don't have to re-do that job.

Inland RV Center, In · 03-26-2009, 04:20 PM

Quote:

Originally Posted by Utahgoldrup

Thanks Bob! I have my vent seals ordered and once I have them, will use acrylclean and a plastic scraper like you mentioned to get the goop off. What is the process on putting the new seals on? Do you put any sealent down first or just put the gasket down, vent cover on top, screw it down and then put sealent around the vent pipe cover? I just want to make sure I put it all back the right way so I don't have to re-do that job.

We supply fiberglass screening material with our sewer vent pipe cover gaskets, at no charge.

The screen is installed over the pipe, then the gasket is slipped over the screening and the pipe. Vulkem sealer is then used to fill the void between the center hole of the gasket and the black pipe, thru the screening for a positive seal.

Andy

ROBERT CROSS · 03-26-2009, 04:52 PM

Quote:

Originally Posted by Utahgoldrup

Thanks Bob! I have my vent seals ordered and once I have them, will use acrylclean and a plastic scraper like you mentioned to get the goop off. What is the process on putting the new seals on? Do you put any sealent down first or just put the gasket down, vent cover on top, screw it down and then put sealent around the vent pipe cover? I just want to make sure I put it all back the right way so I don't have to re-do that job.

Just the way I did it, other options may vary..

After some trial and error I found it easier to just run a good bead on bottom side of gasket, stick over the opening, another bead around center opening and outside edge and vent pipe.
The opening in the shadetree gasket I made fit very tight over the tube and was easy to seal.
Also on this style vent I plugged the access tube for the cap screw that holds the cover to the roof flange.

Tighten those new stainless screws your using carefully

On this style cover the factory saw fit to only install 6 of the 10 screws.

IMHO..might as well fill the empty holes.

Used a stainless screen from an old pasta strainer over the vent opening.

Aage · 03-27-2009, 08:48 PM

Quote:

Originally Posted by Inland RV Center, In

We supply fiberglass screening material with our sewer vent pipe cover gaskets, at no charge.

The screen is installed over the pipe, then the gasket is slipped over the screening and the pipe. Vulkem sealer is then used to fill the void between the center hole of the gasket and the black pipe, thru the screening for a positive seal.

Andy

There's one for each tank right? Black, gray and the fresh water too? (Can you tell I don't live close to my trailer?)

**azflycaster** · 03-27-2009, 09:12 PM

If your 74 is like my 75 Trade Wind, you will have two vents. The Black and Grey tanks share one vent and there is another vent by the kitchen sink.

Inland RV Center, In · 03-28-2009, 10:45 AM

Quote:

Originally Posted by Aage

There's one for each tank right? Black, gray and the fresh water too? (Can you tell I don't live close to my trailer?)

You could have 2 or 3, sewer vent pipe covers.

The water tank venting, is very different than the sewer vents.

The black and gray tanks are the only gasket concern.

Andy

wppii · 03-31-2009, 01:14 PM

Are the vent covers installed incorrectly in the first place?

The top of my plumbing vent cover says to vent the pipe 2" to 2-1/2" above the roof. If the pipe is that high, it will have a friction fit with the lower portion of the vent cover, just like a roof jack on a house, i.e. the pipe will stick up through the center hole tightly enough that a thin bead of caulk will seal the area. That would eliminate the need for a rubber gasket to seal against the outside of the pipe lower down. It would also eliminate the need for any drain holes to get water off the top of the gasket, like the old style vents had. Then the only other place to seal is around the outer perimeter of the vent cover base.

Of course, my vent pipe only sticks up 1-1/2", so, unless I extend my vent pipe, I have to have the inner gasket. But it just doesn't seem to be properly installed.

Am I in left field here?

Silvertwinkie · 03-31-2009, 02:45 PM

Quote:

Originally Posted by wppii

Are the vent covers installed incorrectly in the first place?

To be honest wppii, I would not shock me in the slightest if they were installed incorrectly......

Great pics...I too seem to have a date with my roof this spring, I'll find out then how bad mine is and was installed.

ROBERT CROSS · 03-31-2009, 07:10 PM

Quote:

Originally Posted by wppii

Are the vent covers installed incorrectly in the first place?
Of course, my vent pipe only sticks up 1-1/2", so, unless I extend my vent pipe, I have to have the inner gasket. But it just doesn't seem to be properly installed.

Am I in left field here?

Sure looks like another case of.. "what you can't see, can't hurt 'ya."

This is how far ours came thru the roof, guess we were just lucky.

Did the Mothership see fit to install all the screws?

wppii · 03-31-2009, 10:02 PM

Bob,
Does the tail of the vent pipe sticking out of the roof 1.) stick out far enough and 2.) fit through the center hole of the vent cap base (albeit tightly) so that a seal can be made with the inner hole of the vent cap base?
Bill

wppii · 03-31-2009, 10:10 PM

Bob,
It looks like the vent cap has capability of twice as many screws as were used in the installation. However, the unused screw holes are blocked off by the plastic casting. It's possible that the amount used were sufficient for the curvature of the roof at the installation point.
Bill

ROBERT CROSS · 03-31-2009, 10:24 PM

Bill

1) It appears from your picture that the vent pipe was cut too short to seal properly in the cover.

2) I cut the hole in my gasket a little under size and ran a bead around the pipe under the gasket so it would seal better when the cover is replaced.

H Depot should have what you need to extend the vent pipe a little. You may have to cut a "custom" gasket to fit the slightly larger diameter. Take the piece you cut off and the cover with you so you can "fabricate" in the store.

On second thought it may be less frustrating to try a Mom & Pop first.

wppii · 03-31-2009, 10:28 PM

...is to check diameter fit between pipe o.d. and vent cap i.d. I think it will match. Then I'll work on extending the vent pipe enough to get through the vent cap base opening. After that it should be a simple matter of a perimeter gasket for the vent cap base.
But first, a new vent cap, mine has cracks developing in it.
Pictures and all the info that's fit to print to follow............
Bill

wppii · 03-31-2009, 10:38 PM

Quote:

Originally Posted by ROBERT CROSS

Bill

2) I cut the hole in my gasket a little under size and ran a bead around the pipe under the gasket so it would seal better when the cover is replaced.

....that if the fit is right, there is no need to seal the id of the gasket against the pipe. The pipe will seal to the vent cap base (as designed).
Bill

ROBERT CROSS · 03-31-2009, 10:55 PM

Quote:

Originally Posted by wppii

Bob,
It looks like the vent cap has capability of twice as many screws as were used in the installation. However, the unused screw holes are blocked off by the plastic casting. It's possible that the amount used were sufficient for the curvature of the roof at the installation point.
Bill

Bill
I'm not quite sure of the "plastic casting" (fridge vent?) you mentioned. It looks like you have the same cover. You can see in this photo how well mine was sealed.

The Fridge vent does block two screws in the cover but it does seal ok.
I just used the cover as a template and drilled using a bit stop to keep from grabing any insulation, wires etc.

wppii · 03-31-2009, 11:11 PM

It looks like every other hole in the perimeter of the base flange was filled with a mounting screw. The rest of the "holes" were still blocked off by the original casting process, i.e. never "poked out" in the first place. That's what I meant by plastic casting.

As with your unit, the refrigerator vent inteferes with a portion of the vent cap base.

Communicating a simple idea can be so difficult...

I'll have to take this up in the am, it's time for checking the ligh blocking abilities of my eyelids....gnite

Silvertwinkie · 04-01-2009, 06:54 AM

Just a thought that may or may not prove helpful.

On my Safari, what appears to be a vent pipe is accessible from a closet. I don't know for sure if it is "the" vent pipe, but if it is, you could in theory cut the vent pipe down below the roof line, then, you're extension would not be on the roof having to dance a gasket seal in place. In my case I don't see how it could not be the main vent pipe, but your mileage could vary. My tanks are aft and there are no hidden spaces other than the closet where the pipe has an out of sight place to make it's way up to the roof. Your unit could have a similar design. Might be worth investigating if you are thinking of extending the pipe from the rooftop.

wppii · 04-01-2009, 05:31 PM

Attached, if it works right, is a pdf of the installation instructions for the vent. Got it from the vent manufacturer. It shows the pipe extending just through the center hole of the vent cap base and calls for a bead of sealant on the underside of the hole that is drawn into the joint as the base is slid down over the pipe.

Won't be able to go further till Saturday, called for OT today, working a 48 after that

wppii · 04-01-2009, 06:25 PM

No sealant required around pipe, tight enough mechanical seal around the pipe. The sealant goes around the flange where it contacts the roof, no gasket required.

For RobertCross, note that standard installation calls for only 6 screws, the rest are extras.