Sealing plumbing holes?

[Jkwilson]

Any thoughts on a good method to seal the areas around the places where the pipes pass through the floor?

It would be easy to use foam, but I’d think it would be better if it was something more removable for future.

Closed cell foam and gorilla tape is my leading idea right now. Anybody have a better thought?

[Country Campers]

I think that would be a good idea. I would definitely not use the spray foam , it would be a mess to try to remove if there ever was a problem to fix. Bat insulation stuffed around the pipes could also work but if it got wet it is not fun to work with either. I was looking at mine the other day and was thinking if I could get saran wrap around the pipes and wood floor structure and used the spray foam it would only stick to the saran wrap , not sure if that is possible or not.

Brian

[OurNewEra]

Any thoughts on a good method to seal the areas around the places where the pipes pass through the floor?

It would be easy to use foam, but I’d think it would be better if it was something more removable for future.

Closed cell foam and gorilla tape is my leading idea right now. Anybody have a better thought?

I happened to be under my hutch last night making repairs to my furnace. There was also some plumbing in there. I had intended on closing up the floor penetrations with foam but have resisted so far. As Country Campers stated it would be a real mess if you had to ever remove it.

Depending on what your goal is, seal vs insulate, I think I am going to just use some batt insulation and pack it in the opening around the pipe. Just fill in the gap to prevent cold air infiltration. If you are concerned about bugs or rodents I guess you could put some repellent on the insulation before packing it in the gap. I think the only way to 'seal' would be foam.

[howson]

My thought process...the holes I filled with foam have solid drain pipes and/or with unspliced PEX lines; or unspliced electrical wire. If there's a repair required in these areas, removing foam won't be the major concern. Something else has gone wrong in a big way.

Using the foam is similar to how GD seals the coroplast where different items poke through (drain pipes, etc). It's a nuisance to remove this foam, but not difficult.

I will agree it's messy to apply. I had to tape the bottom side of the holes to keep the foam from falling through. Taping the bottom side is easy with the coroplast down (so the underside is easily accessible).

[Calbar]

My thought process...the holes I filled with foam have solid drain pipes and/or with unspliced PEX lines; or unspliced electrical wire. If there's a repair required in these areas, removing foam won't be the major concern. Something else has gone wrong in a big way.

Using the foam is similar to how GD seals the coroplast where different items poke through (drain pipes, etc). It's a nuisance to remove this foam, but not difficult.

I will agree it's messy to apply. I had to tape the bottom side of the holes to keep the foam from falling through. Taping the bottom side is easy with the coroplast down (so the underside is easily accessible).

I agree with howson Howard with this. I foamed my solid plumbing holes. The one in the hutch with the furnace and in the closet with the water heater I didn't yet and not sure I will be able to due to the way the holes are cut and size. I am thinking some Roxel or fibreglass insulation. Maybe even some solid foam insulation and then foam spray or a combination of any of these.

Rob

[Yoda]

My thought process...the holes I filled with foam have solid drain pipes and/or with unspliced PEX lines; or unspliced electrical wire. If there's a repair required in these areas, removing foam won't be the major concern. Something else has gone wrong in a big way.

Using the foam is similar to how GD seals the coroplast where different items poke through (drain pipes, etc). It's a nuisance to remove this foam, but not difficult.

I will agree it's messy to apply. I had to tape the bottom side of the holes to keep the foam from falling through. Taping the bottom side is easy with the coroplast down (so the underside is easily accessible).

Howard You may want to check with GD on this but I believe those holes allow return air out of the belly back to the furnace. I dont remember seeing any return ducting when I had the belly open. Just wondering.
Keith

[TucsonJim]

Howard You may want to check with GD on this but I believe those holes allow return air out of the belly back to the furnace. I dont remember seeing any return ducting when I had the belly open. Just wondering.
Keith

This is important to remember. There is open duct work from the furnace in the underbelly in order to keep things like plumbing and tanks from freezing. There is no return air path other than through holes in the primary floor. Completely sealing the main floor will block the intended return path and can result in either reducing flow from the furnace into the the underbelly, or forcing the heated air out through any openings in the underbelly. If both the main floor and the underbelly are well sealed, then the flow of warm air can be reduced quite a bit.

Jim

[howson]

Yoda and TucsonJim

Understand the point, but for me there was way too much external temperature (hot and/or cold) coming up through those gaps, not to mention the path for critters.

As far as not letting air out...I highly doubt the coroplast on any GD product is sealed to the point where air can't escape. There is opening I didn't seal--the one where the water pipes go vertical to join up with the Nautilus panel.
Maybe that's a bonus that all the "hot air" from the furnace is directed to that one opening?

[Cate&Rob]

Bat insulation stuffed around the pipes could also work.

I like the idea of stopping air movement with easily removable batt insulation. Good idea, Brian! For those of us with batt insulation in the main floor structure, it is important to be able to quickly and easily vent and drain any moisture that might accidentally get in there. Batt insulation plugs in the holes would do that.

Rob

[TucsonJim]

Yoda and TucsonJim

Understand the point, but for me there was way too much external temperature (hot and/or cold) coming up through those gaps, not to mention the path for critters.

As far as not letting air out...I highly doubt the coroplast on any GD product is sealed to the point where air can't escape. There is opening I didn't seal--the one where the water pipes go vertical to join up with the Nautilus panel.
Maybe that's a bonus that all the "hot air" from the furnace is directed to that one opening?

Do you mean to tell me the underbelly is not hermetically sealed???

[Jkwilson]

Thanks everyone for the input so far.

I hadn’t really thought about the air return idea. That complicates things and also gives me ideas to improve things.

The way I see it:

Holes in the floor, especially those in the utility area of the basement behind the wall are a good thing when heating the underbelly because the serve as return air paths which encourage air flow into the underbelly and help avoid heated air leaking out. They aren’t a good thing when using the A/C because that space is not cooled and isn’t particularly well isolated from the outdoors. Any air leaks to the outside in the underbelly are then connected to the living area via holes in the floor and the furnace air return vent, which is under the hutch in my specific rig.

We currently use part of an old bedspread to block the furnace return during the summer, but it would be nice to have control of the return from the underbelly as well.

The utility area of the basement is not at all well sealed from the basement, but I’d don’t think there are any intentional returns from the heated basement into the utility area.

If you do a good job sealing the coroplast and frame and plumbing cuts in the floor, you may be blocking the primary exit path for furnace air that is forced into the underbelly, so an intentional return with a damper might be a good thing to add.

Some static pressure readings might be interesting

[Wrongwayrver]

After another mouse in my trailer I went on a search and destroy mission looking for access points to my 2017 303. Believe me there are alot of holes in the floor to the interior. First was under the Island 3 in the basement storage area. Behind the fireplace beside the stove either for propane water lines and plumbing. The worst area is behind the hutch area behind the drawers. On the holes I took chunks of wire mesh cut to fit around plumbing etc and steel wool stuffed in the holes. Them foamed it up with a fire proof foam much denser than the standard foam. The hutch area I made three panels or screens fitted to cover the area under the hutch. This still allows a cold air return for the furnace. While I was doing that had a small drip from the soft hose from the HW tank replaced with pex.
The next area of concern is access to under the bedroom flooring from the front storage compartment. Pictures to follow once I tackle this in the next couple of days.

[Wrongwayrver]

To bad the manufacturer doesn't do a better job of sealing up holes in the floor before assembly. Would be much easier than trying to figure it out afterwards.

[Guest]

I've taken a slightly different approach and have sealed the coroplast with critter foam at all gaps. Left the return air paths open in the floor and never store the unit with the stabilizers down to reduce exposure. So far after 5 winters, we have had no mice.

Wife also throws dryer sheets throughout the rig in the fall where I'm not sure if this works or not but we will continue to use them.

Never store food products in the rig.

https://www.amazon.com/3-Pack-GREAT-...03374052&psc=1

Jim

[Cate&Rob]

Wrongwayrver
Hi Randy . . . good to see you posting ideas on here 😁.

I have followed a similar plan to Guest Jim and others in trying to seal the "first line of defence" being the coroplast to the underbody. But, there are any number of access points around slide actuators, etc, that are impossible to seal. A mouse can get through an opening smaller than a quarter. See this related thread for ideas on mouse "repellent". https://gdrvowners.com/forum/grand-d...ice-protection.

Jkwilson John, I just noticed your comment "I don’t think there are any intentional returns from the heated basement into the utility area." from a while ago. There are multiple openings across the top of that wall where it only comes up to the bottom of the floor structure above.

Over the winter (our first winter storing the RV because of Covid travel restriction) I left an assortment of bait traps outside the trailer. (On top of the tires and slide actuators, etc.) I put kill and hold traps inside in case a mouse still ventured inside. All traps inside the RV have remained empty although I am catching mice in the house garage next to the RV.

Rob