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Insulation gaps

PostPosted: Tue Dec 27, 2011 9:56 pm
by Forrest747
Ok i admit it i am not the best when cutting rigid insulation I have a few gaps. For teh front i went with 1 1/2 inch rigid foam. its basically that stryrofoam beads glued together, what a mess to cut for sure. I like the blue dow corning stuff much better but you have to go with what home depot has on hand.

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

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PostPosted: Tue Dec 27, 2011 11:15 pm
by afreegreek
ya, the spray foam in the can works good.. it's also got some adhesive qualities to it as well.. all you need to trim excess away is a sharp knife.. cuts like butta! just wait a day or so.. it can be a little sticky if you don't..

PostPosted: Tue Dec 27, 2011 11:15 pm
by PSBreen
Personally I like the pink or blue foam as it's much easier to cut. The white stuff tends to crumble if there is any drag on your cutting tool.

The best thing I know of for cutting foam is a hot wire bow. My second choice would be those snap blade utility knifes from the dollar store. Use one of those with a straight edge and you should get nice clean cuts. Don't try to cut all the way through in one pass. Several shallow passes will lessen the chance of crumbling/beading up the foam. Note Styrofoam will dull the blade faster than you think so don't hesitate to change the blade when it starts dragging.

PostPosted: Wed Dec 28, 2011 9:47 am
by aggie79
afreegreek wrote:ya, the spray foam in the can works good.. it's also got some adhesive qualities to it as well.. all you need to trim excess away is a sharp knife.. cuts like butta! just wait a day or so.. it can be a little sticky if you don't..


I used the spray foam to fill the gaps in my insulation and around the wiring.

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As afreegreek says, give the foam adequate time to harden. The foam cuts and sands real easy. I used one of those flexible flush cutting saws to trim the foam, but a knife or even a hack saw blade works well.

Take care,
Tom