Insulating a floor above a garage
So this is happening more and more in my office now where we are designing townhomes with a garage below the living space and now that we are building these units in a cold climate I am beginning to have greater issues with it due to the plumbing that needs to run through the floor cavity that is above the garage.
Typical construction is 12-16″ open web floor joists which the contractors want to use R-30 fiberglass batts that I find unacceptable because of the large gaps that will be in place. My ideal method would be to hold plumbing tight to floor and install a rigid material between the floor joists to create a chase and then pack the cavity tight. However I know due to cost, the contractor/developer will not want to pay for anything more than R-30. So how do you satisfy a code official that states the insulation needs to be tight to the underside of the floor deck?
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