Community Forums

Greg O · 02-14-2020, 07:54 AM

Well folks I have a 24' Thor Class C that I bought new only 4 years old. About 2 years ago rain started to come in under the floor (and then filling above the floor) of the front overhead bunk area. I re-caulked EVERYTHING in sight from front to rear! I also cut small 'inspection' holes in the front corners of the upper floor. While there is no more actual puddles of water visible any more, I still can see and feel definite dampness under the floor after any heavy rain. I have taken it to 2 different RV dealers to have the whole RV pressure tested, but nothing really shows up. I am at a loss now! Any thoughts on this would really be appreciated!

Thanks, Greg

Ray,IN · 02-14-2020, 08:33 AM

Remove the clearance light lens and inspect for a water line mark. I had that happen to a 5er once. The lens had a gasket sealing it to the base; however, the gasket leaked water into the lens. The lens filled with water until it reached the wiring hole in the cap, ran into the hole and followed the wiring down into the wall.
I solved the problem permanently by drilling a 1/8" hole in the bottom of every clearance light lens.

Hope that helps.

ksg5000 · 02-15-2020, 09:50 AM

When I had similar issue it turned out to be a small leak in one of the side windows. Common sources for leaks are the top running lights and front/side windows. I took apart the front bed to insure that the area was bone dry before putting it back together - you may find some insulation in there (mine was in the nose cone) which would need to be removed/replaced.

Joe I · 02-16-2020, 06:40 PM

We had a leak right behind the front cap, dealers couldn't find it. It was where a corner trim mated to the top, the factory sealant didn't stick to the two pieces. I cleaned it all thoroughly. Then sealed it with the best sealant I could find.

Point is, look everything over carefully, if it leaks you can find it, it's up to you. You might hose down each area and see which area leaks.

THenne1713 · 02-16-2020, 06:50 PM

Common leaks are corners/ joints UNDER metal trim, running light fixtures, window frames and CONDENSATE/ SWEATING? A PINLESS moisture meter can help on papers/ smooth walls and PIN TYPE moisture meter CAN be used on carpeted ceilings. Newer models I see are Combo PIN/ PINLESS mOISTURE METER, about $60 at HD/ Lowes? Luck, and Let us Know?

jacwjames · 02-16-2020, 06:51 PM

If there is the corner molding that has the plastic strips pressed into it I would inspect there. I had the same problem and it was how they installed it, they didn't do a good job sealing. I had to remove and redo all of it and make sure to caulk the screw heads of the screws thoroughly. YouTube is your friend.

bkobernus · 02-29-2020, 02:46 PM

My only addition to what everybody else has contributed is: the gasket on the roof air conditioner. I think that's what my problem is. Can see any other holes or cracks anywhere.

roygfleming · 02-29-2020, 05:12 PM

I would remove some of the plastic trim insert from around the cabover and remove a screw or two to look for rust. Rust equals water intrusion

Florida Rang · 02-29-2020, 08:03 PM

Yes, roof a/c gasket needs to be re-tighten every couple of years. More often if you travel on rough roads regularly. I had to tighten my Greyhawk 2018 last month, it leaked by the filter.