Originally Posted by 62overlander
I use Reflectix on every single job. I swear by it. Heat from the outside is reflected back out and cool from the inside is reflected back in. It works in reverse too. Highly effective stuff. I wish it was around when I did my own trailer. I believe in this product so much that I am considering gutting my entire trailer out to do it.
For the end caps, I cover them before installing them. Care must be taken to not put the insulation where the fiberglass meets the rib. The thickness of insulation will effect getting it back into proper alignment. I use a cabinet grade spray contact cement to adhere it to the end cap. All seams get covered with aluminum tape.
The Reflectix acts like a big decal if you spray the skin with the contact cement, allow it to dry, then spray the back side and put the wet glue into the dry. Cutting things precisely is very important. I go right up to the ribs. Any seams are covered with aluminum tape.
I then do the wiring.
Next I install a second layer held behind the backside of the ribs. The aluminum tape covers all the ribs and gaps and makes it into a big ballon. The air gap in between the two layers is about 1 1/8". Once the first layer goes in I have to work inside the trailer with all the windows open since the heat from my shop light builds up quickly.
I thought that you were a devout Prodex guy? I stock both, & have used both, Reflectix for the past 10 years & Prodex only the past year or so, in all of the restorations we've done. Reflectix doesn't claim any "R" value & Prodex claims R 16. R 16 seems pretty optimistic for a product this thin, that isn't NASA spec, but who knows. I do know that on trailers that we used reflectix in, then filled the remaining space with fiberglass, the inside temp remains the ambient temp, with no AC running & the windows open, so when you touch the inside skin, it doesn't feel hot to the touch, however with fiberglass alone (my 59 Ambassador is a "survivor" & still has the original fiberglass), the interior skin is hot to the touch, even with AC running. We have done tests with a Pyrometer & discovered that in direct sun & 100 degree ambient temp, a polished exterior skin will hit 145 degrees. An unpolished skin will hit 155 degrees, so polishing obviously reflects some of the heat. Our problem is to reduce the temp from 145 degrees to a livable temp, in only one & a half inches. Plus we still have the thermal bridge issue caused by the ribs. I'm still "up in the air" whether the significant cost differential between Reflectix & Prodex is worth it.
Many seem to get upset about the potential condensation inside the walls, but I have never seen evidence of water between the walls, with the exception of obvious leaks or urine streams from vermin. If there is condensation, there isn't much.
Have you done any definitive tests, or is it more "seat of the pants"?