THe problem i have is that there are a few gaps, mostly 1/2 to 3/4 inch. so thinking once i put the interior panels in; glued stapled epoxied and then trimmed out I thinking of spraying that expandable foam. i think i saw someone did that to thier wire runs in the roof and trimmed it out nicely. what is the secret to trimming the expanding foam or is it worth all the hassle