I thought I would add my thoughts on this here too rather than just in my build, so that it would be easier for others to find.
Here is what I posted in my build:
A preliminary verdict on the bottom insulation.
So far since putting my under frame insulation in I have travel well over 100 miles on gravel roads and about 300 miles on paved. I am seeing nothing but a little dust on the canvas covered insulation. I also have three small sections in the front of my ct that have mostly uncovered pink foam insulation. It shows a little dust and maybe a couple of little tiny rock dents. No real wear at all.
I private messaged BC Dave about his insulation also. He glued on his insulation with no covering. He hasn't traveled as much with it, but it is holding up fine and shows no damage.
Then I saw this post by Nobody. He has had uncovered insulation on the bottom of his camper since 2006, and had it on all kinds of roads.
Nobody wrote:There probably as many answers to your question as there are builders on this forum. None are 'wrong' or incorrect. What's right for one person may not work as well for another.
I built my TD in 2006, using an HF 1800# trailer & a couple of profile drawings I expanded from quarter inch graph paper. I built my floor from ripped spruce 2x4's, 1x6 pine for side rails, & 1/2" CDX ply for the decking. After the 'floor' was completed I inverted it on a couple of sawhorses & 'painted' it with asphalt roofing compound. Contrary to conventional wisdom, the coating wasn't nearly as 'stinky' as expected, & the 'tackiness' only lasted as long as it took to dry (overnight). I then cut pieces of 1" styrofoam (Dow 'blueboard') to fit the recesses under the floor, installed them with PL Adhesive, & as an extra caution, I used small pieces of scrap wood as 'battens', 'nailed' to the floor frame with 18ga brads from my HF nailer/stapler. Almost 8yrs & 20K plus miles later (towed thru all kinds of terrain from freeway to National Forest/BLM back country roads/trails) the foam shows considerable stains/marks of travel, a few tiny 'gouges' probably from road debris, but NO deterioration or tendency to 'de-laminate' from the floor. In SE New Mexico in 2010 we encountered standing water in the streets of several towns, that in places almost 'floated' the TD. I've also driven through lots of heavy rain/T'Storms where I'm sure the tires & passing vehicles sprayed lots of water up under the TD. I've found no indication of residual moisture nor any evidence of rot in the wood portion of the floor, nor corrosion to the metal of the trailer chassis. As an aside, I live in central Arkansas where our average humidity is quite high & equipment not properly protected has ample opportunity to suffer ill effects from it...
Here's a few pix of my floor under construction
This how the underside looks this morning (not bad considering what it's been exposed to since 9/2006)
I think we have been over thinking and over engineering floor insulation. I don't regret covering my insulation with the canvas/paint coat, but after having seen how my uncovered insulation is holding up and how little "wear" others have experienced, I think it will be more than adequate for the long haul. I am wondering if the "cover the insulation" comes from RVs and trailer houses originally using fiberglass batts that needed protection from water etc?????
I will continue to check on mine on how it is doing, but I won't be canvasing over the small odd shaped pieces of exposed foam that are in the front. I will be doing some foam fill in spots that I haven't gotten to yet, but that is about it.
In short, if I was to do it again I would glue and screw the insulation on, or batten it, but I wouldn't worry about putting a cover over it. You could always do that later on if you wanted.
by BC Dave » Sat Dec 14, 2013 1:56 am 
