# Insulation to fit between 4-inch rafters



## Windows on Wash (Aug 30, 2011)

Radiant foil needs an air space to work.

Rigid polyiso is going to have the best R-value but still won't be adequate at 4".

You will need to look critically at the venting as well and moisture control.


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## joecaption (Nov 30, 2011)

Is this space even able to be converted.
By far most attic were never designed for use as a living space or even storage space.
The biggest issure is the width, spacing and span of the joist.

There needs to be a ridge vent, soffit vents, baffles for air flow from the soffits to the ridge vents before any insulation ever goes in. With just 2 X 4's that would only leave room for 1" of insulation.


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