# Floor insulation for porch / study



## Nealtw (Jun 22, 2017)

So your basement is below this?


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## bajinganindy2 (Jun 18, 2020)

no it's not. right underneath this porch is just soil(ground).If you draw a straight line down from The wall where that sidings is on, that is the basement wall.


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## Windows on Wash (Aug 30, 2011)

Where is the home? Easiest will be foil faced foam and some joist cavity fill.


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## Old Thomas (Nov 28, 2019)

I insulated one like that from beneath by putting foil faced bubble insulation up against the floor to maintain a small barrier between the insulation and the floor. Then I filled the cavity with mineral wool batts. The final step was covering the bottom with plywood to keep critters from taking up residence in the insulation.
I considered spray foam, but the price was too high for what I wanted to do.


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## Anglib56789# (Nov 11, 2017)

Id screw a 2 inch foam board between the joists, cut to size. then fiberglass rolls, then plywood or waferboard.


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## ratherbefishing (Jan 13, 2011)

We installed a sun room on a deck. Ceramic tile floor on Wonderboard. Not much different from what you're doing. I put R-19 (?) pink fiberglass insulation between the joists, then nailed old fashioned blackboard sheathing to the bottom of the joists. The blackboard has sagged a bit in places. It's not real pretty. But no problems so far.


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