foil radiant barrier over decking

[belfastjim]

In my yet to be built unheated workshop in Maine, I am considering a foil radiant barrier (Prodex) in lieu of felt on the sheathing. Over this would be some furring strips for ventilation and then a standing seam metal roof. I am hoping that this foil product would reduce the solar heat gain through the roof.

Would this work?

[canuk]

Curious .... why the furring strips for ventilation if you are using standing seam metal roofing?
If you were using asphalt shingles then I would agree with the air gap.

If you are concerned with conductive heat transfer .... you could consider laying down rigid foam sheets on the decking directly under the metal roofing.
This would provide an advantage of a continious thermo break preventing heat gain and loss.

[belfastjim]

I just wanted to vent the exterior of the roof, so heat wouldn't transfer it's way through the shiplap sheathing. I am not sure of the future plans regarding insulating the building. Do you know if rigid foam would work under metal? Wouldn't there be condensation problems on the back side of the metal?

[Ray Henry]

Originally Posted by belfastjim

In my yet to be built unheated workshop in Maine, I am considering a foil radiant barrier (Prodex) in lieu of felt on the sheathing. Over this would be some furring strips for ventilation and then a standing seam metal roof. I am hoping that this foil product would reduce the solar heat gain through the roof.

Would this work?

A radiant barrier reflective foil will really work. Use a double sided perforated verson. This verson works both ways, it keeps the heat/cold from entering yous work space as well s keeping in heat/cold in the room. I have it installed in my home over the attic insulation and over 9 months have saved over $1,259.00 on my electric bill by reducing the kilowatts used each month by an average of 44%. I also sell and isntall the radiant barrier foil in homes and commercial buildings in south Texas where heat is more of a problem than cold. Visit my website at www.environmentalenergyimprovements.com for more background.