It goes without saying line-x has no insul value. The line-x is to cancel out further reliance on the plastic. The line-x is to strengthen it, hold it all together. Armor plating in a sense. With the second coat applied just before I brought it home from line-x, it has now lasted for a long time and affords some respite, some shade, from the hot sun.
I will not use reflectex any more. It was not on my escape hatch, if you read above. I used it for insulation under my mattress and in a couple years the coating was flaking off and spreading everywhere. Not knowing what the coating is and wary of metal dust that could contain lead, I'll stay away and am glad I did not use any overhead.
Being an engineer does not give anyone all the answers. This has been my experience. They are not entitled to the entire worlds supply of credibility. None of us deserve that except God.
What I experienced with Reflectex and the amount of clean-up.... you can have the remainder of the roll I bought.
Eventually my hatch will break down to the point I'll have one made of either stainless steel or aluminum with welded corners.
Way I figure it... if you have a Heki it's already broke and can be replaced with far better materials at a better price.