Water in underbelly

[CLARKR4]

I had just finished cinching down the ADCO cover straps that fit under the underbelly and noticed a small gap between the coroplast and the frame to which it was screwed, door side just in front of the wheel on the front axle. I pushed up on the coroplast and noticed that the screw heads on three screws were no longer attached to the body of the screw. They must have been torqued too much at the factory and the expanding hole fill must have been holding the coroplast in place until it could no longer hold the weight of the wet insulation, which I could feel as I was able to stick my hand into the cavity. I duct taped the coroplast to the frame and took the unit back to my dealer, not wanting to leave a moisture condition for the winter.

They have removed the coroplast on both sections of the underbelly and the insulation is waterlogged. They have checked all plumbing connections and report they are solid. I am told that there are no overflow outlets on any of the tanks other than the dump valves. We have had no overflows of any of the sinks or toilet.

I have suggested to my service tech that they need to check all connections to the tanks, check the tanks for any minuscule punctures of the tanks as there has to be a leak somewhere. It just does not seem plausible to me that any road water from rain could penetrate the underbelly, especially in that small gap mentioned above.

I have been reading about the vacuum breaker check valve problems that are connected to the black tank flush and wonder if that could leak into the underbelly. Any other known explanations?
Thanks for your thoughts.

Rich

[Cate&Rob]

CLARKR4
Hi Rich,

Good that you found this before putting the RV away for the winter.

There are many sources for a plumbing "drip" leak (often at a soft hose to Pex fitting connection) that could slowly accumulate water in the underbelly over an extended length of time. Do you recall the water pump coming on while camping, when no one has opened a faucet? A leak like this would be very difficult to notice if connected to campground water supply. I wonder what the dealer did to determine that "all connections are solid"? A visual inspection could quite likely miss something small. A pressure test over an extended length of time would be ideal. Easy to do if you have a system pressure gauge permanently installed, but attaching a pressure gauge to the cold water low point drain would accomplish the same thing.

I would not under-estimate the possibility that this is rain water. Have you been towing in heavy rain? (You are in BC )

The Solitude design with insulation laying directly on top of the coroplast creates a big "sponge" that can gather a lot of water. Unless you are planning a lot of cold weather camping, you might want to consider having the dealer re-install the coroplast without replacing the batt insulation. This is the way that Reflections are built and if water gets into the underbelly, it drains out quite easily. An "improvement" to the original design would be to install closed cell foam insulation above the coroplast that would not absorb water.

Rob

[howson]

Unless you are planning a lot of cold weather camping, you might want to consider having the dealer re-install the coroplast without replacing the batt insulation. This is the way that Reflections are built and if water gets into the underbelly, it drains out quite easily.

Rob,
The Reflection TTs have the foam core insulation in the floor that the 5th wheels do not (if I remember correctly when we toured the production line). The 5th wheels have the plywood attached directly to the frame, batt insulation then inserted underneath. There's no need for the batt insulation on the travel trailer since the floor is effectively the same construction as a wall, but without the batt insulation on a 5vr wouldn't the only "insulation" be the plywood floor and coroplast?

Howard

[Cate&Rob]

Rob,
The Reflection TTs have the foam core insulation in the floor that the 5th wheels do not (if I remember correctly when we toured the production line). The 5th wheels have the plywood attached directly to the frame, batt insulation then inserted underneath. There's no need for the batt insulation on the travel trailer since the floor is effectively the same construction as a wall, but without the batt insulation on a 5vr wouldn't the only "insulation" be the plywood floor and coroplast?

Howard

Hi Howard,

Good question. I "think" Solitudes have batt insulation in the spaces of the aluminum floor framing, which is the same as Reflection 5th wheels (and is similar to the foam insulation that you have in your Reflection TT.) The batt insulation above the coroplast in a Solitude is in addition to the batt insulation within the floor. If I am incorrect on this (and there is no batt insulation within the Solitude floor framing) then it would have to be replaced above the coroplast.

Rob

[Second Chance]

Hi Howard,

Good question. I "think" Solitudes have batt insulation in the spaces of the aluminum floor framing, which is the same as Reflection 5th wheels (and is similar to the foam insulation that you have in your Reflection TT.) The batt insulation above the coroplast in a Solitude is in addition to the batt insulation within the floor. If I am incorrect on this (and there is no batt insulation within the Solitude floor framing) then it would have to be replaced above the coroplast.

Rob

You are correct, Rob - Solitudes have insulation both places:

https://www.granddesignrv.com/showro...e/construction

(Another) Rob

[CLARKR4]

Rob, Rob & Howard
Thanks for chiming in.
We have not towed in heavy rain since returning from Texas in March. When we spent 3 weeks on Vancouver Island in September we had heavy rain while stationery but not while towing. Are you suggesting that heavy road water can migrate into the underbelly when there is no obvious access points?

How the tech checked the connections was a question in my mind as well, since I had winterized. I suggested that they had to de-winterize, pressurize the system and run all systems. Also while the system is pressurized, to connect the black tank flush and fill the black tank to close to full and check for leaks.

I do not remember the water pump coming on as we rarely use it. The only time I have used the water pump recently was for the winterizing. How or why is the water pump connected to a leak? The tech has suggested that when they re-install the coroplast they are going to put an extra barrier under there. I didn't get full details or dwell on that because I told them that we shouldn't be restoring the underbelly until we find the leak which has to be there somewhere.

I will suggest the pressure test as you suggest, by attaching to the cold water low point drain. Do you have a permanently installed system pressure gauge installed, what do you use it for and how do you read it?
I will keep you posted on our progress of diagnosis.

Thanks

Rich

[CLARKR4]

Rob
I have been asked twice now about driving in rain storms. Is it your impression or experience that the underbelly seal on Solitudes is such that road water can penetrate the underbelly? Prior to the Solitude our three previous 5th wheels have all been Glendale Titaniums and one predecessor model Golden Falcon. Their underbelly coroplast was attached with screws and that steel strapping that ran the full perimeter and anchored the coroplast to the frame. This method was superior to a screw and washer every ?? inches around the perimeter. I have never had water in the underbelly due to poor sealing, with any of those units. I guess with my situation of the loose corner and wind turbulence while traveling, water could be forced in, but I wouldn't think that it could spread throughout the underbelly.

Rich

[Second Chance]

Rob
I have been asked twice now about driving in rain storms. Is it your impression or experience that the underbelly seal on Solitudes is such that road water can penetrate the underbelly? Prior to the Solitude our three previous 5th wheels have all been Glendale Titaniums and one predecessor model Golden Falcon. Their underbelly coroplast was attached with screws and that steel strapping that ran the full perimeter and anchored the coroplast to the frame. This method was superior to a screw and washer every ?? inches around the perimeter. I have never had water in the underbelly due to poor sealing, with any of those units. I guess with my situation of the loose corner and wind turbulence while traveling, water could be forced in, but I wouldn't think that it could spread throughout the underbelly.

Rich

Forum hint: since there are several "Robs" involved in this discussion, it would eliminate any confusion about whom you are addressing if you use the "Quote" when replying (as I've done here).

I think you were addressing the "Other" Rob, but the Coroplast on the Solitudes is very well sealed. I would be surprised if, in the absence of a breach of some kind, if that amount of water were able to make its way in due to driving in rain.

Rob

[CLARKR4]

Forum hint: since there are several "Robs" involved in this discussion, it would eliminate any confusion about whom you are addressing if you use the "Quote" when replying (as I've done here).

I think you were addressing the "Other" Rob, but the Coroplast on the Solitudes is very well sealed. I would be surprised if, in the absence of a breach of some kind, if that amount of water were able to make its way in due to driving in rain.

Rob

Rob
Got it. Thanks for the hint and the answer. The last of water penetration is reassuring, as not being able to drive in rain storms, would be a huge limitation.

Rich

[Cate&Rob]

CLARKR4 Second Chance howson

For whatever reason, we do seem to have a lot of "Robs" on this forum. Apparently there was a name shortage in the 50s. I have two first cousins within a year of my age, also named Robert . . . apparently our great Grandfather made a significant impression on our mothers. But, I digress . . . tagging the Rob you are replying to is a good idea.

Back to the topic at hand . . .
I have a very sensitive water alarm cable laying inside the coroplast. It will alarm with condensation level moisture or a major flood. It always goes off after towing in the rain. I don't know how the water gets inside the coroplast, but I expect that the water spray from the tires has something to do with this. In my case (with no batt insulation laying on top of the coroplast in my Reflection) the moisture dries or drains in a day or so and I can reset the water alarm with no further remediation required.

The fact that you use campground water supply rather than your onboard pump could be key to this. A drip leak (from a soft hose to Pex fitting) would not be detectable with "city" water supply. This could have been slowly dripping into the batt insulation above the coroplast for months.

I do have a permanently installed system water pressure gauge (covered in other discussions, but I can add here if you are interested). This is the best $15 improvement that you can (easily) add to you water system. A multitude of uses. System pressure can be far different than what the pressure gauge on your supply line shows. Monitoring pump cut-in and cut-out pressures. Seeing pressure rise when the water heater is turned on. Seeing whether low flow at a faucet is flow restriction or lack of system capacity . . . and so on. Also, per this discussion, monitoring for a slow leak.

Rob (one of them)

[CLARKR4]

CLARKR4 Second Chance howson

For whatever reason, we do seem to have a lot of "Robs" on this forum. Apparently there was a name shortage in the 50s. I have two first cousins within a year of my age, also named Robert . . . apparently our great Grandfather made a significant impression on our mothers. But, I digress . . . tagging the Rob you are replying to is a good idea.

Back to the topic at hand . . .
I have a very sensitive water alarm cable laying inside the coroplast. It will alarm with condensation level moisture or a major flood. It always goes off after towing in the rain. I don't know how the water gets inside the coroplast, but I expect that the water spray from the tires has something to do with this. In my case (with no batt insulation laying on top of the coroplast in my Reflection) the moisture dries or drains in a day or so and I can reset the water alarm with no further remediation required.

The fact that you use campground water supply rather than your onboard pump could be key to this. A drip leak (from a soft hose to Pex fitting) would not be detectable with "city" water supply. This could have been slowly dripping into the batt insulation above the coroplast for months.

I do have a permanently installed system water pressure gauge (covered in other discussions, but I can add here if you are interested). This is the best $15 improvement that you can (easily) add to you water system. A multitude of uses. System pressure can be far different than what the pressure gauge on your supply line shows. Monitoring pump cut-in and cut-out pressures. Seeing pressure rise when the water heater is turned on. Seeing whether low flow at a faucet is flow restriction or lack of system capacity . . . and so on. Also, per this discussion, monitoring for a slow leak.

Rob (one of them)

Rob with Cate
I have had the service dept at my dealer pressurize the system, fill the black tank, keep the system pressurized for fresh water, while turning on the black tank flush line, and no leaks. I have read something about the Vacuum Break Valve that has something to do with the Black Tank Flush that could leak? Apparently it is behind the shower, so how would one see a leak coming from there? Also where would the 'soft hose to Pex fitting(s) be located? I have suggested to my GD customer relations contact that having a metal strip secured by the screws along all perimeter edges of the coroplast would make for a better seal against road water, but she says that they have found that the screws and washers are sufficient. Odd that there is one metal strip running across the width just in front of the front axle. Not sure why there and not all around. I have attached a picture. Not sure if my case fits the exception, but I am substantially concerned about restoring the underbelly covering without finding the source. I was told that GD puts a few holes in the coroplast that are intended to drain minor amounts of moisture that gets in the underbelly. I did see a few holes about the size of a dime, but they didn't seem to do all that much in my case.

With regard to the system pressure versus the supply line pressure, why would there be a big difference there? Or is that not a simple answer. I am interested in your System Water Pressure Gauge. I assume you are not talking about the one that I have on the end of my hose end that fits to city water? So if you can explain again or refer me to where it is already recorded.

Your sensitive water alarm cable, would it be much help in the event of a major leak? I guess you would know quickly and could turn the water off to minimize the damage.

Still searching for answers before getting the underbelly restored.

Thanks to all for the comments. I didn't attach the picture as I couldn't figure out how to attach it.

Rich

[Cate&Rob]

CLARKR4
Hi Rich,

I would agree that finding the source of the water before reinstalling insulation and coroplast would be a good plan.

The black tank flush and the potable water systems are completely separate. Keeping the fresh water system pressurized has no affect on testing the black tank flush system. The vacuum break for the black flush line has to be above the rim of the toilet (per RV construction code) so is usually located behind the shower wall. On a Solitude, this valve is usually accessed through a removable panel in a closet adjacent to the back of the shower. A leak from this valve usually shows up on the floor of the main level, but might find its way to the underbelly without showing up anywhere else.

The soft hose is used in many different places throughout the plumbing system . . . so a drip leak from one of these connections could be almost anywhere.

I have never seen drainage holes in the coroplast, put there by Grand Design. These would not be very effective at draining water, once the batt insulation on top of the coroplast was wet.

Th water pressure system is isolated from the city water connection, or the onboard water pump, by check valves. A pressure gauge T'd into the system allows you to to "see" the pressure in the system. To confirm a small leak, I would disconnect the city water hose and turn off the pump. If pressure drops in the system over time, there is a leak somewhere. The pressure gauge on the input hose tells you the fill pressure, but not what is going on inside the trailer water system past the inlet check valve.

The sensitivity of the water alarm is an issue. It can't tell the difference between condensation moisture and gallons of water. But, since any water in the underbelly should be investigated, it is a valuable warning.

Rob

[CLARKR4]

Rob
So where do you connect the pressure gauge? I have seen a water regulator with a gauge attached. Is that the same item you would use for the water system pressure test. If not do you have a picture?

Thanks.

Rich

[howson]

I didn't attach the picture as I couldn't figure out how to attach it.

See Insert Photographs in your Thread: https://gdrvowners.com/forum/gdrv4li...in-your-thread

[Cate&Rob]

Rob
So where do you connect the pressure gauge? I have seen a water regulator with a gauge attached. Is that the same item you would use for the water system pressure test. If not do you have a picture?

Thanks.

Rich

A pressure gauge can be “T” connected to any cold water line. Most who install one of these do so at the water control panel. I have two. One at the water panel and one in the bathroom. The one in the bathroom was easily T connected into the cold water Pex line to the faucet.

Rob