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Topic: How do I remover the kitchen countertop if the grey vent pipe runs through it? (Read 436 times) previous topic - next topic
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How do I remover the kitchen countertop if the grey vent pipe runs through it?
Looking for advise if anyone has removed their kitchen countertop before. My main concern is that the grey water vent pipe runs through the countertop in the corner.

It doesn't seem like an easy unscrewing of the pipe since it looks to be glued onto the next joints.

Has anyone dealt with this, or have any recommendations?
1995 23.5 Rear Lounge
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #1 –
I don't know the Rear Lounge floorplan.  On my MB, the black tank vent goes through the counter.  I will assume that the approach will be similar.  On mine, the vent is accessible from underneath the counter and from the over-sink cabinet.  If you want to hide the connection, those are where you make your cuts, but they are not an easy space to work in.  You will need four joining pieces (unions?), and the right kind of cement. 
1. Prepare the counter for removal.  I would expect that you will find both clamps and caulk holding it in place.
2. Remove the faucet, the sink and any drain plumbing that is in the way.
3. Make a level cut in the cabinet and below the counter, in each case at least the length of the unions from the surfaces in the cabinet and under the counter.  Making the cut a little further along makes re-assembly easier, but do not make it less than the length of the unions.
4. Slide the counter away from the wall.  The vent should have enough flex to move the counter several inches.
5. Slide the vent pipe down to clear the cabinet.
6. Slide the counter out further until the vent clears the cabinet, then slide the vent up and out of the counter.  The counter is now free.

To put things back together:
1. Clean any burrs from the edges of the vent cuts, all four of them. 
2. Take the unions and using a file, a Dremel or similar, remove the ridge on the halfway point inside the unions.  Two are to be spacers.  The other two will form the splice.  All four must be able to slide fully onto the vent pipe.
3. In the cabinet and under the counter, measure the length of the union, then use a marker and mark the pipe at half that distance from the cut.
4. Slide a union onto the vent in the cabinet until it is flush with the cut.  Put a dab of cement at the edge of the union away from the cut, then slide the union up until the mark shows at the bottom edge of the union.  That spacer is now ready.  Do the same with the vent pipe below the counter.  It is much easier to do this BEFORE you put the counter back.  Each end of the vent pipe that was not removed should now have a union in place, acting as a space, leaving a stub of vent pipe about half the length of a union.  (NOTE - if you prefer you can use band clamps as spacers.  You still need to remove the ridges on the two unions so they can slide fully onto the pipe.)
5. Position the counter on the lower cabinet so that the removed vent can be re-inserted.  Slide it down into the counter, move the counter in, then slide the vent up into the cabinet, sliding one of the unions onto the vent pipe until it is below the cut edge.
6. Wiggle the counter out until you can slide the remaining union onto the vent pipe, then put the counter back in place.
7. Use the appropriate pipe cleaner solvent on one of the vent ends. Working quickly, apply the glue to the two vent ends under the counter and slide the union down until it meets the union used as a spacer.  Do the same with the union in the cabinet.  The vent should now be together and sealed.
8. Use some blocks of wood to raise the counter up and hold it in place while you apply caulk to the frame surfaces that were caulked before.  Remove the blocks and redo the catches.  Let the caulk dry, and the counter is now back in place.  You can now replace the sink, faucet and drain plumbing.

There are other ways of doing this, using threaded unions, but they can work loose with vibration, and getting tools in there to tighten them is not easy.

No, I have not done this on my rig.  I have had occasion to cut and rejoin plastic pipe in my house, and this is how I did it.

Ken F in WY
'08 MB
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #2 –
Hi Tom; just a comment on the tanks. Your rear lounge is the same as a TK, but on the driverside you don't have the outside storage compartment, and you do have two lounge barrel chairs.  The vent pipe next to the shower wall is the gray water tank. Forward of the bathroom wall in the overhead there is a 45 degree angled partition about 8" wide. Behind that is the black water tank vent pipe.
 Not an easy job to remove the counter top, sink, stovetop. Mine is still in good shape ('99) so far. To access the water tank, or the cord storage area, and connections for electrical. Also the propane line going to the stovetop/oven that will need to be removed, along with the glass divider.   RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #3 –
I just want to know why you want to remove the countertop?
Don & Dorothy
Sold our LD in June of 2023

Our boring always non-PC travel blog
Traveling Dorothy
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #4 –
@Kenneth Fears thank you for the super detailed explanation!! Now I have a game plan!

@RonB thanks for confirming, I not iced the other pipe by the bed and figured it would be the black tank, but wasn't 100%. Now I am, and also have the store already out :)

@Don Malpas I'm in the middle of renovating the RV interior so I wanted to swap out the counter with a butcher block countertop. However it started to look a lot harder with the pipe running through it....
1995 23.5 Rear Lounge
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #5 –
After looking into vent pipes, I came across Air Admittance Valves, which seem to do the same job of providing air intake when there is negative pressure in the pipes such as using them or specially dumping out the tank water.

Now I'm thinking of replacing the vent pipe with the Air Admittance Valve so that I don't have to have a pipe running up through the countertop.

Would anyone know of any BIG NO NO for doing that?
1995 23.5 Rear Lounge
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #6 –
Quote from: majortom  - 
After looking into vent pipes, I came across Air Admittance Valves, which seem to do the same job of providing air intake when there is negative pressure in the pipes such as using them or specially dumping out the tank water.

Now I'm thinking of replacing the vent pipe with the Air Admittance Valve so that I don't have to have a pipe running up through the countertop.

Would anyone know of any BIG NO NO for doing that?
I'd be concerned about pressure changes inside the tank due to temperature changes and/or altitude changes.  An AAV will let air in during negative pressure situations, but what above positive pressure inside the holding tank?  I'd be concerned that the gases could be forced past the toilet ball seal (black tank) or through a p-trap (gray tank).  A vent pipe is always normalizing to outside air pressure.

Art
Art and Barbara
Settled in Atterdag Village of Solvang
2015-2022 fulltime in a 2016 Tiffin Allegro Bus 37AP
2002-2015 2002 LD MB
Art's blog
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #7 –
"I'd be concerned that the gases could be forced past the toilet ball seal."
---
And, depending on how full the black tank was, perhaps an "upward effluent release"?  :o
2003 TK has a new home
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #8 –
Hi, Well majorTom is referring to the gray water tank, not the black. Gray tanks can smell pretty bad, (I put biodegradable treatment in the gray tank also).  I believe there is enough room at the corner of the shower to relocate the vent pipe behind the wall in the area above the kitchen counter, and then back to the present pipe inside the cabinet above the kitchen counter.  You may have to put in a smaller diameter pipe, but it is just air and gray water vapor. With the counter top off you could cut an access hole to look and see if there was enough room for a pipe relocation.
   As Art said, temperature and altitude changes would pressurize the tank and gasses would come up the traps in the sink or shower 'P' traps.  When my LD is sitting in the driveway unused, every few weeks I pour water back into the traps, to keep odor at a minimum.   RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #9 –
Quote from: majortom  - 
After looking into vent pipes, I came across Air Admittance Valves, which seem to do the same job of providing air intake when there is negative pressure in the pipes such as using them or especially dumping out the tank water.
Would anyone know of any BIG NO NO for doing that?

If that was a practical or legal way to plumb the holding tank's vent, LD would have used it to eliminate the vent in the countertop.

An Air Admittance Valve is a one-way valve that lets air in and prevent it from escaping. Its purpose to promote draining into the sewer by breaking the vacuum that occurs when water flows down a drain.
The holding tanks produce gases that build in pressure due to heat and biological action. With an air admittance valve replacing the vent pipe, the gases will be trapped in the tank until they find a way to escape, most likely into the interior. If you enjoy the tank's fragrant perfumes, you will be thrilled

Air Admittance Valves are primarily used for home remodels where it is difficult or impossible to vent a new drain to the roof and are not the preferred method for venting. The plumbing codes have specific rules pertaining to and limiting its use.

A flat butcher block countertop will not drain the same way as the Factory countertop and will require continuous maintenance to maintain, it is not intended for near-constant exposure to moisture.
Are you planning on using teak or other wood that can better handle mositure exposure?

Larry

Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #10 –
thank you all for the great advise!

seems like the vent pipe is still needed for the positive pressure I didn't account for. hopefully I can hide it even if with a smaller pipe between the shower and kitchen wall.

since the pipe would be smaller, the AAV would help with the higher negative pressure of flushing the grey water; but the positive pressure is usually gradual and a small pipe should still do the trick it seems
1995 23.5 Rear Lounge
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #11 –
Quote from: Larry W  - 
A flat butcher block countertop will not drain the same way as the Factory countertop and will require continuous maintenance to maintain, it is not intended for near-constant exposure to moisture.
Are you planning on using teak or other wood that can better handle mositure exposure?

Larry

we are thinking about using a bamboo one or a lot of coating on it to have a good look, but keeping away the issues with moisture.... still in planning mode on that department....
1995 23.5 Rear Lounge
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #12 –
Ah, grey tank vent; of course. Thanks. But, as noted, grey water can stink (and bubble up), too. Might be an opportunity to offer a few tips to new RVers on grey tank management.

Stainless steel sink strainers trap food particles in the galley sinks and hair and whatnot particle in the washbowl and shower. These are easily emptied (a couple whacks into the trash can liner) and cleaned with a toothbrush if they get goopy.

https://www.homedepot.com/p/DANCO-2-1-2-in-Lavatory-Mesh-Sink-Strainer-88820/203675133

Using a silicone or rubber spatula to scrape the gubbins off dishes and pots and pans into the trash before washing them helps to keep food scraps out of the grey tank. If the plate or dish or cooking pot is pretty "clean", a wipe with a paper towel before washing works very well.

Dispose of any cooking grease in a tin can or a "nest" of aluminum foil and put it in the trash; never put grease down the sink.

Every once in a while, a baking soda and white vinegar "blast" in the sink, shower, and wash bowl drains clears any gunk. Sprinkle a couple tablespoons of baking soda into the drain, pour in a couple "glugs" of white vinegar and watch the crud bubble up. Repeat as necessary.

Using a bacteria and enzyme tank treatment in the grey tank was well as the black helps to keep the tank "unstinky".

YMMV.

2003 TK has a new home
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #13 –
Air Admittance Valves:

I have used these in houses.   The first one was for a toilet.  I was skeptical when the plumber suggested it (huge bathroom remodel and the closest vent was now about 10’ away so this was easier).  I was concerned about smells over time but talking to plumbers and inspectors gave me confidence. 

They work well.  They are acceptable - eg in the plumbing codes (committees of knowledgeable pros create these based on industry experience) and these codes are what are used for state/county statues (laws) - sometimes with a few modifications. 

The vents have been used for over 20 years - last one I had installed was about 2015 (for a sink).  That person I am in contact with regularly and I have heard of no problems (and would have if there was any smell issues).

Concerns about pressure from the fixture side going up the pipe - I would not expect anything in an RV greater than plunging a toilet in a house and obviously it withstands that well.

I don’t see a problem in using these vents  in an RV (bouncing moving home) it is the same as any plumbing fixture.  Just make sure you secure it to the wall well just below the valve (all pipes should be secured at regular intervals - part of the code).  Read the installation instructions - your install is easier, they need air so when I put them in walls I put a vent (eg like a floor or wall vent for Hvac) on the wall and in one case that vent was inside a cabinet.  But I would not stuff soft material around that vent - it does need air.

A side note on Kent’s instructions.  Make sure the pipe glue is for the pipe you are using (there is a difference).

I was hesitant but will also mention Fernco - flexible couplers. In a tough spot it makes things a little easier.
These are used with sticky situations (eg 50 year old pipes that have different dimensions than current pipes).  They are approved by code for pipes with water as well as air vents.  I did use one at the bottom of a stack (eg main pipe that goes into the ground) that had a ton of smaller pipes leading into it (it was my only choice).  But I left an access to that spot for just in case - no problems in 8 years).
I am hesitant however to use these in a bouncing moving home.  I am conservative and would never use it for a wet pipe (water going down it).  But if I couldn’t use regular abs pipe I would seriously consider it for a vent pipe.  However I would want to check it is screwed tight regularly.

Another possibility (again a second choice to Kent’s install) is taking a coupler and cutting it clean lengthwise.  Then gluing it on the pipe, fitting it tight and adding glue to fill the cracks from the cut.  While any home inspector would say hold on, if you said you tried really hard and could not get it on with the regular pipes and fittings they likely would accept it (they are not unreasonable for difficult situations as long as the solution looks good).

Of the 3 alternatives to Kent’s standard description, I personally would go with the air admittance valve but because I am cautious, I would do things in such a way If I needed to put a standard pipe there in the future I could.

Jane





Jane & Scott
Currently have a 1989 TK  LD we did a lot of upgrades on.
Bigfoot 25RQ Twin on order with early summer 2024 ETA

Our smartphone autocorrects into very poor English.
 We disclaim the illusion of ignorance this creates as we have enough ignorance we rightly claim.
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #14 –
For what it's worth, eight years ago my midbath's gray water dump pipe was broken by an encounter with a rock (see "Rock Attack!") and repaired with a Fernco-style rubber coupling. There were no leaks up until I sold the rig three years ago, and as far as I know there have been none since then.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #15 –
An air admittance valve is intended to allow air into the pipe.  A household plumbing system does not trap and hold water.  Water flows through, and the valve is there to prevent a vacuum or siphon effect.  Air flow is one direction - from the room into the pipe.

In our RV's we fill the grey water tank.  The air in that tank has to vent someplace.  If an air admittance valve is used and works properly, it will not allow air into the cabin from the tank.  Yet, the air in the tank has to go someplace.  It will bubble up through one of the traps, either the sink traps or the shower trap.  (If there are any plumbers out there, and I am wrong, PLEASE correct me.)

I think if you cap the lower end of the vent pipe with an air admittance valve, you will quickly have a stinky RV.

Ken F in WY
'08 MB
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #16 –
Andy, good point.  The grey vent pipe could be cut, then instead of all the craziness of my description above, two rubber couplings could be used.  Good idea.  MUCH simpler.

Ken F in WY
'08 MB
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #17 –
As others have said - you want a vent pipe that run all the way up to the roof.

If there were an easier/cheaper method that would last at least until the warranty was over, you bet the major manufacturers would have eliminated their roof vents by now!

I would guess that wooden countertops would add some weight.  The molded fiberglass countertop is a really good fit for the job it does in the RV, IMHO.

Rich


2003 MB
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #18 –
Air admittance valves  in sticks and bricks are used in conjunction with an open vent. They do not replace the venting system for septic or sewer systems. They allow for a drain to be located where an open vent cannot be plumbed, but they are part of the entire system that is vented. You must be able to vent gasses from any plumbing system.
Sand Castle (Theresa & Everett) Surfside
01'  26.5 Mid Bath,   2018 31IB
Michigan born and starting to explore the US with my  spouse and our furry friend. Enjoying joining LD group rallies.
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #19 –
Andy - good to know your fernco fix worked.  Good enough at least that there have not been any complaints.  Was that spot vertical or horizontal and was the pipe secured to the LD solidly before and after the fernco coupler (less room for wiggling)?
Jane
Jane & Scott
Currently have a 1989 TK  LD we did a lot of upgrades on.
Bigfoot 25RQ Twin on order with early summer 2024 ETA

Our smartphone autocorrects into very poor English.
 We disclaim the illusion of ignorance this creates as we have enough ignorance we rightly claim.
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #20 –
Quote from: Jane and Scott  - 
Air Admittance Valves:
I have used these in houses.  The first one was for a toilet.  I was skeptical when the plumber suggested it (huge bathroom remodel and the closest vent was now about 10’ away so this was easier).  I was concerned about smells over time but talking to plumbers and inspectors gave me confidence. 
The vents have been used for over 20 years - last one I had installed was about 2015 (for a sink).  That person I am in contact with regularly and I have heard of no problems (and would have if there was any smell issues).

Your home sewer is not a sealed system, there is no pressure build up. Air admittance valves are perfectly acceptable in this application.
They are also used in RV's with vented tanks. Our LD's bathroom sink has one, up high inside the sink's cabinet, installed by LD to promote the sink's fast drainage, with no blowback. 


A holding tank with an admittance valve, and without a vent pipe, would be sealed,
How and where are the tank's gases and the pressure build-up going to escape?
If there is no outlet to the roof or exterior, once the pressure builds, the fumes will find the weakest spot to escape.  Since almost all the drain plumbing is inside the coach, the leakage most likely will occur there.
There needs to be a vent pipe to the roof.

Larry


Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #21 –
A note:  a fernco fitting is not made for movement, other then the slight vibrations of a pipe when water travels down a long vertical pipe.  So if I used one, I would
- secure it to limit stress (pipes on either side secured well and pipes inline with each other (no offset)
- check it regularly to make sure it still held tight (they can be tightened more if needed and you want them snug - just don’t crack the pipe underneath)
- check it regularly to make sure it is not degrading - meant for indoor temperature not extreme hot or cold.

Air admittance vent, I was told there was a filter so If some air came up the air admittance value it would not smell (that was 20 years ago).  And there were other vents in the house to the outside.

I checked the discussion of 2018 plumbing codes and one vent to outside air is needed (per system). Maybe a reroute could be done - I have always been surprised the one in our TK was in the corner of the kitchen and was not put in the wall just inches away.
Jane



Jane & Scott
Currently have a 1989 TK  LD we did a lot of upgrades on.
Bigfoot 25RQ Twin on order with early summer 2024 ETA

Our smartphone autocorrects into very poor English.
 We disclaim the illusion of ignorance this creates as we have enough ignorance we rightly claim.
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #22 –
Larry, typically there is one vent per fixture though they are often joined together as they head towards the outside.  So if there is only that one vent by that sink (it doesn’t have a second one somewhere) that would be the one.

In your picture, it kills me that LD installed PEX that way.  The big plus of PEX is that is bends (off the top of my head a 1/2” pipe is a 6” bend) - so you use less fittings.  Every fitting is a place for potential leaks and typically adversely affects the PSI.    It is like having wiring with a splice mid wire - another potential trouble spot).
With PEX you can do a Tee (to make a branch towards a new fixture) put in some support for the bends (or just properly fasten the pipe to the wall on each side of the curve) and connect to the fixture (eg sink in this case). And it is not done to have a solid piece (brass) to connect to the wall - I don’t see those fittings fastened down (PEX specs come from manufacturers and say where the pipe is fastened to a wall including x distance from each fitting).
Jane

Jane & Scott
Currently have a 1989 TK  LD we did a lot of upgrades on.
Bigfoot 25RQ Twin on order with early summer 2024 ETA

Our smartphone autocorrects into very poor English.
 We disclaim the illusion of ignorance this creates as we have enough ignorance we rightly claim.
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #23 –
great source of knowledge here, thank you all for pitching in!

I checked on the space between the kitchen wall and the shower, and there is barely 1inch if anything so that can't do as a replacement route for the vent pipe to the ceiling. However, there might be space between the kitchen wall and the outside (next to the window) about 5inches!

So with that, I think installing the AAV along with a smaller pipe running through the wall I'll be able to "meet code" having a vent pipe to the roof (smaller but should handle the small amount of pressure for air to escape, and along with the AAV it should handle the negative pressure when dumping the grey water tank
1995 23.5 Rear Lounge
Re: How do I remover the kitchen countertop if the grey vent pipe runs through it?
Reply #24 –
"Was that spot vertical or horizontal and was the pipe secured to the LD solidly before and after the fernco coupler (less room for wiggling)?"

Horizontal. And the pipe hangs from suspension rods, as I recall, so I wouldn't say that it's solidly secured. See the "Rock attack" page I mentioned for photos.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"