# How to insulate a shed floor sitting on gravel



## dalepres (Mar 20, 2011)

I have a pre-built shed about 12x32 feet that I want to insulate. I want to put in a PTAC heater/AC and maintain the temperature in the shed between 80 in the summer and 40 to 45 in the winter just so I can store things in it that shouldn't freeze.

The shed sits in 4x4 runners with 2x6 joists above that. The runners are sitting on about 4 inches of 3/4" max limestone gravel.

There's just no way to get under it to do proper insulation. I wish I had ordered it with floor insulation when I bought it but that's long past; it's been there about 5 years.

About the only option I can think of for insulating the shed is blowing in insulation right on the gravel. and closing in the ends and sides somehow to keep the insulation in place as best I can.

Will this work? Anything so wrong with the idea that makes it just not something I should do? Even better, any better ideas on how to insulate under this shed?


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## joecaption (Nov 30, 2011)

Forget about blowing it in, just never going to work.
You going to be loosing the least amount of heat out the floor, far more important to air seal the walls and ceiling, air seal any air gaps or holes, add a vapor barrier then insulate.
About the best you can do is add a layer of 3/4 foam to the floor and go over that with 3/4" T & G plywood to act as a thermal break.


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