Rain water off roadway floods basement membrane

After driving south 175 miles in heavy rain we stopped for lunch. I noticed clear water flowing out between the bottom membrane and the bottom of frame rails on both sides of the 5er directly over the wheels (New 2014 Bighorn #3685RL). The membrane was sagging down as if it had extra weight above it.

The unit was winterized and had ZERO water in any of the holding tanks. We came from the north country and the unit was winterized prior to freeze up in September.

After more inspection, I noticed a 2" +/- hole on each side of the frame rail over the wheels. This hole was factory cut so that the slide room hydraulic cylinder ram would have room to move in and out. There was no type of rubber seal or foam seal around either of the hydraulic cylinder rams. I suspect that the excess opening around each ram is where the water entered the basement.

Since then the weather has been dry and all water has stopped flowing out of the membrane and the membrane has stopped sagging down.

Has anyone heard of this problem? Do I need to add some type of water seal around each slide hydraulic ram?

Lakeside

Although your gap is large, I had the same problem where the leaf spring shackles are welded to the frame. I purchased 1/8" flat aluminum, 2" wide strip stock from Home Depot and cut it to fit; then I screwed it to the frame rail with self tapping screws. I also used a black water sealant before tightening the screws. I've not noticed any more leaks.

I believe that member JohnDar made up some seals using an inner tube.
I'm sure he will see this and add some pictures.

Peace
Dave

You are not the only one, I would have thought that would have been addressed by now...

Thank you. I will try to locate JohnDar for more information.

Lakeside

I'm on my iPad and don't have the photos on it, but I just took an old inner tube and cut a patch big enough to cover the opening with about an inch margin. Then I cut a slit so it would slip over the piston rod and made a 1/2" hole for the rod. Used small stainless steel self-tapping screws to attach it to the frame (drill pilot holes). I did it to keep critters out of there, but it probably will keep a lot of road spray out, as well.

The coroplast on the bottom of these rigs is at best a cover. I wouldnt think of it as a water proof barrier. If you tow in the rain your going to get water up under the coroplast. Water flung off the wheels at 60 MPH(no wheel wells here), blasts up under the coach with alot of force. I would suggest you find the low spot in each section of coroplast, and put a 1/8 to 1/4 hole there, so the water that collects in it.... can run out on its own. Even the drain holes in my UDC, cause water to wick into the coroplast sitting still on my rig, while filling the water tank. There is NOT a water proof seal where the frame and the coroplast are screwed together.

sengli said:

The coroplast on the bottom of these rigs is at best a cover. I wouldnt think of it as a water proof barrier. If you tow in the rain your going to get water up under the coroplast. Water flung off the wheels at 60 MPH(no wheel wells here), blasts up under the coach with alot of force. I would suggest you find the low spot in each section of coroplast, and put a 1/8 to 1/4 hole there, so the water that collects in it.... can run out on its own. Even the drain holes in my UDC, cause water to wick into the coroplast sitting still on my rig, while filling the water tank. There is NOT a water proof seal where the frame and the coroplast are screwed together.

Click to expand...

Great Idea. I will add this to JohnDar's inter tube method. Between both of them, I should be in better shape during wet road trips. Thank you for taking the time to respond.

Lakeside

Great idea. I will follow your directions. Thank you JohnDar.

Lakeside

Greetings everyone. I am new to this forum but I came here to seek an answer to my problem. Fortunately I found this thread which comforts me to know that others are having the same problem we did and we were not the only ones. We are from Alabama and in August we took a trip to Michigan for a couple of weeks. From Ohio to Michigan we went through torrential downpours that followed us the entire distance. It took us 10 hours to go only 360 miles. After setting up in the campground, I noticed the entire underbelly was sagging to the point of almost touching the axles. My first fear was that I had busted a line or tank from the honey wagon that had drained our tanks before we left the previous campground. So for three days we did not hook up to water and we used the bath houses. Instead of continuing to Canada, we took the RV to Camping World in Michigan. They dropped the underbelly and massive water poured out. The insulation was drenched. The tech guessed that possibly 1,000 lbs of water came out. They did a complete water system pressure test and found no problems there. The tech showed me the several large holes in the frame above the tires and suggested that water probably came in through there during the driving in the storms. They contacted Heartland and they agreed to cover the cost of repair, although they said they've never heard of such a thing happening. Camping World replaced all of the insulation and replaced the underbelly. When we got home I put some 2" duct tape over the holes and I hope we never have that problem again. Thank you all for your inputs on this forum. Very helpful indeed!

Hello Wingram12 and welcome to the forum. As you have already found out, there is a ton of good information here.
It's good to hear that you seem to have solved your water issue.
Oh, if you used duct tape to seal the belly it probably will not hold up very well.
Some people have had good luck using Gorilla tape or Nashua flashing tape.

Peace
Dave

Thanks Dave. At the time the duct tape was the only thing I could think of. However, I am liking the idea that JohnDar posted and I think I might try it out. It looks like it could be very beneficial in keeping the water out of the underbelly.

Cookie is probably right on the use of the Gorilla tape instead of regular duct tape to seal all the seams and I added more screws and fender washers. I also plugged a lot of the openings with expanding form to fill some of the wider voids and just used black paint to match the under belly... I did mine almost 3 years ago on my 2011 "Big Country" mainly to keep mice out but it seems to help keep the road water spray out as well.

Better late than never, I realized I never added a photo of the piston rod close-out. The Gorilla tape is still there after a couple of years.