D
dog_and_a_minnieOP
Pull-Through
Duluth, MN
15 posts · joined Sep 2025
Sep 14, 2025 · 4:20 PM#1
vacuuming the cabover on our 2020 Minnie Winnie 22M after a weekend at Jay Cooke and the plywood at the front passenger corner of the bunk gives a little when i push with my thumb. not squishy, just not like the rest of the deck. no stains on the cab ceiling underneath that i can see and the front cap looks fine from the ground.
we bought it used two years ago. is this the start of the cabover rot everybody warns about, or is it the mattress deck foam getting old? pictures of the corner from inside and from the ladder coming tonight.
C
cabover_leak_hunter
State Parker
La Crosse, WI
33 posts · joined Sep 2025
Sep 14, 2025 · 10:03 PM#2
front passenger corner is the usual spot on a lot of C's. that is where the front cap seam turns the corner, and when you drive in rain the water runs back along it. a thumb test is a start. get a pin type moisture meter, the $25 one from the hardware store works, and check that corner against the middle of the deck. dry plywood reads somewhere under 12 to 15. north of 20 means water is getting in right now.
also lift the mattress and look at the staples along the edge of the deck. rusty or black staples mean it has been wet for a while.
D
dog_and_a_minnieOP
Pull-Through
Duluth, MN
15 posts · joined Sep 2025
Sep 15, 2025 · 7:40 PM#3
meter came home from Menards. middle of the deck reads 9. the corner reads 17 right at the edge and 11 about eight inches in. staples along that edge have some orange on them. the outside sealant looks ok to me but i would not know good from bad. pictures up: the corner from inside, the outside seam, and the clearance light on that corner.
E
e450_brakes_joe
Long Hauler
Ames, IA
41 posts · joined Sep 2025
Sep 19, 2025 · 6:12 AM#4
17 at the edge and dropping fast as you move in is the good version of this story. small entry point, caught early. my money is on that clearance light. at the shop we find marker lights more often than seams. the gasket under those little lights shrinks, a screw loses its bite, and water walks in around it.
pull the light, scrape off the old putty, lay new butyl tape, and go one screw size up if the holes are wallowed out. half an hour and ten bucks.
C
cabover_leak_hunter
State Parker
La Crosse, WI
33 posts · joined Sep 2025
Sep 24, 2025 · 8:55 PM#5
agree with joe. in your third photo the light is sitting crooked, you can see a gap along the bottom edge. do that first.
then look hard at the lap sealant where the front cap meets the sidewall. on a 2020 it is likely the original and it starts to alligator around year four or five in our winters. if you can get a fingernail into a crack, clean it with mineral spirits and lay a fresh bead over it. do not use silicone, nothing sticks to it afterward and the next person to reseal it will curse your name. dry the deck with a small fan and the furnace on for a couple of days and meter it again before you close anything up. the owner resources at winnebago.com list what sealant they used if you want to match it.
D
dog_and_a_minnieOP
Pull-Through
Duluth, MN
15 posts · joined Sep 2025
Oct 4, 2025 · 11:17 AM#6
fixed, i think. the light had exactly one screw that just spun in its hole, and the putty behind it was dry as a cracker. new butyl and a #10 screw. there was a hairline crack in the lap sealant running down the side, so i ran a bead of Dicor 501LSW over the whole corner seam while i was up there anyway.
space heater and a box fan for three days and the corner reads 10 now. total damage $31 and a saturday. my husband has started calling me the leak person.
W
weekends_at_mankato
Dry Camper
Mankato, MN
12 posts · joined Sep 2025
Oct 21, 2025 · 9:48 AM#7
bookmarking this. we are still shopping and i am now the guy who brings a moisture meter to every dealer lot. the salesman in Owatonna did not love it. he let me anyway.
