Underbelly failure

[cltskybear]

So bought my new Vengeance in early 2017...normal issues, etc. One day when driving home through mountains in a heavy rain, I noticed the underbelly black plastic sagging. By the time I got home, it had collapsed and the insulation had torn out and dragged on road. Took it to local RV shop and they found no leaks. They repaired it under warranty and I was on my way. No issues until last trip, second time driving through rain, I noticed that the underbelly was once again torn apart and insulation hanging down. Is this what I can expect every time I drive in the rain? Both times it separated near the 3rd axle where the pieces of cheap black plastic are held together with black tape. The back piece falls down a bit and then scoops up all the road water until it finally collapses. Anyone else having this issue and if so, what was a permanent fix?

[MR.M]

The factory never installs enough fasteners . you'll need to get some self tapping sheet metal screws some fender washers and add double from what the factory installed . silicone around the entire edge and any openings you can use great stuff or something similar . I did my unit the first week of ownership . dropped the entire underbelly , added foam insulation , secured all electrical wiring and water lines . then reinstalled underbelly using the great foam around the entire edge before as i reinstalled then silicone around all edges and twice the number of fasteners . in 4 years towing across country in plenty of rain never an issue

[schwyl]

I replaced mine with diamond plating.

[TitanMike]

Originally Posted by MR.M

The factory never installs enough fasteners . you'll need to get some self tapping sheet metal screws some fender washers and add double from what the factory installed . silicone around the entire edge and any openings you can use great stuff or something similar . I did my unit the first week of ownership . dropped the entire underbelly , added foam insulation , secured all electrical wiring and water lines . then reinstalled underbelly using the great foam around the entire edge before as i reinstalled then silicone around all edges and twice the number of fasteners . in 4 years towing across country in plenty of rain never an issue

I had my "underbelly" down while upgrading some wiring. Replaced the "Ramset Nails" with screws. Also sealed the edges with aluminum tape that is used to seal heating sheet metal work.

I worry more about an edge coming loose and catching the air at highway speed that will then rip the rest of the fasteners loose. Keep the air out and that risk is close to nil.

Put over 8,000 miles on the TT since this work and not a sign of any issues. BTW, towed in lots of rain too.

If securing the coroplast with silicone caulk/adhesive just remember that you may have to access the area behind it someday and the more permanent you secure it, the harder it will be to do so. Good screws with fender washers and an aluminum tape seal seems to satisfy both needs. Securing and still leaving future access.

[Flybob]

Unless you can find and seal the Coroplast, I would add a few small weep holes to allow the water to drain. You can install directional vents to prevent water from entering.

[TitanMike]

Originally Posted by Flybob

Unless you can find and seal the Coroplast, I would add a few small weep holes to allow the water to drain. You can install directional vents to prevent water from entering.

Can't speak for all but mine has two of what you suggest from the factory. A couple of louvered vents, one right behind the FW tank and the other between
Black and Gray tanks.

FWIW, if one drives a lot in wet/rainy areas it might be a good idea to get a set of the big mud flaps that mount to the hitch draw bar and have the brush like fringe on the bottom. Could cut down on the amount of splash that is coming up against trailer bottom after being tossed up by Tow Vehicle. TT's tire splash would then just pass out behind trailer.

[Brewhedd]

Pieces shouldn't be joined with tape. Should be wood cross-pieces that the plastic ends can be screwed into.

[TitanMike]

Originally Posted by Brewhedd

Pieces shouldn't be joined with tape. Should be wood cross-pieces that the plastic ends can be screwed into.

My underbelly cover is a single piece. Where I "tape" is at the edges where it ends at the frame and sags 1/4" or so between screw/washer fasteners. Structurally the tape is doing nothing, just keeping air and water from blowing in.

[BLOODYBILL]

soon to take delivery of a vengeance model 348A13 the end of this month
this thread is a good heads up,i will be checking my under belly and if needed put some modifications on it,

a question rodent problems is there much or any on the vengeance?
thanks in advance