Can I Plug Vent Under Shower???

[RickO]

While removing and cleaning all of my "P Traps" today, I was really surprised when I removed the access vent plate to get to the shower drain. I saw a LOT of daylight from both the plumbing bay and through a 12"x12" hole right under the drain which I believe opens right to the gray tank. I was using the Fantastic Fans at the time and a nice cool breeze was blowing into the coach through these openings.

I am one of those who's basement a/c has a hard time keeping up with the heat so this looks like a great place for me to plug a potential problem area and help the coach stay a bit cooler on hot days.

Is anyone aware of any reason I shouldn't replace the vent-type grate on the base of my shower with a solid plate to stop this leak?

Thanks,

Rick

[ernieh]

That vent is there for a reason. My guess is moisture which will eventually equal mold and rot. It's also a probable return air source for the holding tank area when using the furnace. You probably don't get much outside air thru that vent when running the AC because the AC recirculates inside air.

That being said, you might want to consider some type of temporary block for very hot days.

[Hikerdogs]

I believe ernieh is correct in his assumption that the "hole" is for the return air when using the furnace. We also have a similar return air port under the galley and bathroom sinks.
One time we filled the cabinet under the bathroom sink so full of towels it blocked off the return port. The end result was we froze (and cracked) the outside shower faucet. Since then we take care not to overload the cabinets. With continuous air flow in cold weather we haven't had any further problems.

[TXiceman]

Probably open to get some flow through the bays for winter heat.

Ken

[RickO]

Bingo! Thanks all. We've been looking at it more closely and I was seeing daylight because the plumbing bay door was open. I figured out that at least one reason it is there is to provide heat to the plumbing bay in cold weather.

[azloafer]

Quote:

Originally Posted by Hikerdogs I believe ernieh is correct in his assumption that the "hole" is for the return air when using the furnace. We also have a similar return air port under the galley and bathroom sinks. One time we filled the cabinet under the bathroom sink so full of towels it blocked off the return port. The end result was we froze (and cracked) the outside shower faucet. Since then we take care not to overload the cabinets. With continuous air flow in cold weather we haven't had any further problems.

How about filling the hole with that expanding foam? I have a couple that I may do. Joe

[RickO]

Quote:

Originally Posted by azloafer How about filling the hole with that expanding foam? I have a couple that I may do. Joe

The area I'm talking about would be too large to fill with foam Joe. It's really quite a large area. Be sure to see my comments above before closing off any openings. I can now see what the purpose is of that opening.

[azloafer]

Ooops. I misread the post. Sorry, Joe

[JWatkins]

I have the same rectangular opening in my coach. I transmits road noise and is wide open for bugs to enter. Fidguring that it has to there for a purpose, I bought some plastic filter mesh and cut a piece to fit. This still lets the air pass but should resist most of the bugs. It also cuts the road noise a bit.
Joe

[Chief]

Same set up on our coach. I, like Joe above used the plastic mesh filter stuff to cover the hole below the shower and I also cut some of that shiny bubble type insulation to go behind the grate. During cold weather I remove the insulation behind the grate for better heat circulation.

[agiledog]

When we had trouble with the black water tank smell, I noticed this too. If the outside service compartment door is closed, you don't see the daylight. This is part of the "heated basement" they talk about. The gas furnace gets its cold air return through there. If you try to plug it off, there is a lot of area to plug besides the hole under the shower. On our coach, it is also open by the toilet and raised raceway behind it. Keep the service door shut and you shouldn't get any air from there.

This was how I found the leak on top of the holding tank. I closed up the coach, opened the outside service door and turned both roof fans on high. There was a lot air coming from there and it was really smelly.