Mike in Arkansas wrote:
Does anyone have any actual experience with the radiant barrier paints?
Are they as effective as aluminum barriers assuming both are applied
against the roof decking?

I had our builder install radiant barrier paint. They applied it on the
underside (visible from the attic) of the roof decking. I'm also in
Texas (Dallas area) where the temps are currently getting to the high
90's. I honestly don't know if the paint helps, because I have nothing
to compare it to. My cooling bills are still very high, but who knows
how high they'd be without the paint. We also did the blown cellulose
insulation, which certainly looks like it would be more effective than
the standard stuff. That attic still gets very hot so I'm thinking that
the paint is not that great, or there was a problem with the way it was
applied.

I have the same problem as the OP in my gara..shop. It's a three car
garage with the metal doors facing west and it gets downright toasty in
the late afternoon. I just added panels of of exterior sheathing (foil
on one side, R5 value)and I really don't think it helped much. I'm now
comtemplating an exhaust (or intake) fan arrangement of some sort. I
have a side door which is currently unused and blocked by equipment,
but I could utilize it for a fan. The door is near my shop area and I'm
thinking I could set up a heavy duty box fan to pull in fresh air
through an AC filter and crack one of the garage doors to allow the air
to escape. That way I'd be pulling slightly cooler air from the east
and exhausing it to the hot west side.

I could also install a window AC unit in that door, but I think the
cost to operate it would be astronomical.

Tom