2020 Starcraft Wet Floor Insulation After Towing In Rain

Update: I have managed to gain access to the insulation sections outside the frame rails behind the wheel wells. To achieve this I pulled the staples from under the lower edge of the aluminum siding, so I could pull the siding out a little. This allowed me to see the plastic sheeting, where it wraps around the edge of the floor joist and is sandwiched between the floor and side wall. Using a knife and straight edge (fabricated from an old hinge to provide an offset from lower edge), I was able to cut the vertical section of plastic sheeting at the mid point. After pulling the plastic down, I was able to pull out the wet fiberglass insulation (a stick helped at the ends of the cavity).

I was anticipating the insulation would be separate sections cut to fit between the floor support beams. However, it appears to be one large sheet that is installed across the floor beams before the plastic is stapled in position. When the floor structure is dropped onto the frame, the insulation is compressed where it becomes sandwiched between the floor beams and the frame. Where I have removed the insulation, this compressed section is still trapped between the beams and frame, and hopefully will dry out before too long. The fiberglass insulation is still present in the section between the main frame rails but the water ingress into this area is less severe.

In the areas outside the frame rails, I have now replaced the fiberglass insulation with polystyrene blocks that should not absorb water if the area gets wet again. I am now in the process of reattaching the plastic sheeting using 2" wide FlexMend tape. This will cover the slit cut in the vertical section of the plastic sheeting and will be completely hidden when the aluminum siding is put back in place. Other than some added sealant, the repair should not be obvious to anyone looking underneath the trailer (e.g. future trade in).

Next I will be looking at adding some corrugated plastic between the frame rails, to better protect the openings in the plastic sheeting around the holding tanks. Since the waste drain plumbing was not designed to accommodate this, it is going to be a little more challenging that it would be on other trailers. Overall this is turning into quite a project, all of which could have been avoided with a little bit of design effort and attention to detail during the build process. I feel the RV industry needs a wake up call, much like the auto industry had with the arrival of Japanese imports.

Once you fix the wet, you may want to consider putting corroplast between the frame rails. I did and it helped a lot. I also added mud flaps that extend all the way up, and a long way toward the ground.

If you remove the wet insulation, I would replace with whatever width extruded board insulation that is a good fit. Once done, you should not have an issue if the board insulation gets wet in the future. At some point, we all tow in a hard rain. You can even piece in the extruded where necessary, and could be glued to the floor, depending on the design??

Jerry

Thank you for all the responses so far. Having read the warranty restrictions in detail, it looks like they give themselves several get out clauses. These include exclusions for damage due to the environment and consequential damage such as mold and mildew. If they just attempt to seal everything without removing the wet insulation, I suspect I am heading for problems down the road.

While the fiberglass insulation may dry our rapidly in a dryer climate like California, I suspect it will take much longer here in New York (currently 52 F with 69% relative humidity). The wet insulation is in contact with the wooden structure of the trailer body, so I would like to get it dried out ASAP.

For clarification, the trailer does not have an enclosed underbody, so there is no Coroplast sheeting spanning the gap between the lower frame rails. The plastic sheeting I mentioned spans the entire width of the trailer and runs across the top of the frame rails.

Agree with the above,
Took me an hour to seal up all the voids and haven't looked underneath since.

The dealer will laugh behind your back or right after you walk out the door. They do not put much effort into making sure these POS's are watertight, especially underneath and around wheel wells where you can't easily see. Out of sight, out of mind.

Get some caulk and foam, crawl under and start sealing anything you see where you think water could be blowing in. It's going to take some time, and you'll never get everything. It's like chasing a Unicorn. The Coroplast underliner is more for hiding the shoddy workmanship than it is for keeping water out.

What's to address? It's fiberglass insulation that dries out pretty quickly. Anywhere there is a hole it's going to get wet. My insulation gets wet all the time.