How to insulate corregated steel under a concrete slab???

Question

Hi all -By front porch pad is concrete poured over galvanized, corregated steel plates.  Underneath is a full 13 course foundation depth.  I recently added an insulated door from my insulated basement into this uninsulated, under porch space.Since I did that I've gotten a huge amount of condensation on the steel plating inside that area at times.  I figure I need to add a layer of insulation to cover the steel plating on the inside, but I'm not sure what kind to use.I was thinking about the great stuff foam, but it would turn into a huge mess - plus I have 160sqft to cover.  Ideally I'd like to find a spray paint type application that I can use since troweling something into the corregrated grooves would be hard.  Is there anything like this out there?I considered using the rigid foam board, but I think the gaps between the depressed parts of the steel and the foam would still allow condensation to form and drip down from the edges...Any ideas?

dpb · Accepted Answer

Gunnite?

Cliff Hartle · Answer

You need something like this. is the first homeowner applied product I've seen.  Its mostly done by Pros with truck mounted equipment.

Larry Caldwell · Answer

Rigid insulation. Bead board or Styrofoam(tm). Construction adhesive will hold it up. Tape the seams to prevent condensation.

You will need to do something to deal with the moisture in the air, which is the source of all the condensation. Put down a vapor barrier on the ground, like visqueen, and run it up the concrete block.

Tony Hwang · Answer

Hi,How about spray foam?

Edwin Pawlowski · Answer

would take them longer to find your house than to spray the 160 sq feet.

Rick Blaine · Answer

This looks really interesting! Would really like to see some field historyreports. Will play with the calculator to see how it price compares withtraditional applicators.

marson · Answer

Handi foam is another brand that's been around for a few years. I've used it to insulate rim joists. Messy and expensive, though it does work. If you can figure out a way to do it with rigid as another poster suggested, that'd be the low cost way I'd go. You might try a contractor, but their equipment is expensive, and setup and cleaning is the same for a big or small job, so they'd probably bend you over a log for such a small job.

Steve Barker · Answer

There are companies that can spray the "great foam" type of stuff in great quantities.

How to insulate corregated steel under a concrete slab???

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