R Matte Plus 3 Sun reflector solution for cooling hot 2nd floor in summer. Flat roof home in Dallas Texas

Many N. Texas homes like mine have "attic" type 2nd floors. Commonly known as a "1 1/2 story," The 2nd level is fully finished out with 3 bedrooms and 1 bath.  But the tax rolls define it as a 1 story house.

 The 2nd story has a 7.5' ceiling.  The 2nd level roof  is flat and has a tiny attic space. Since the entire house is cooled by a single 5-ton air conditioner,  the 2nd floor gets uncomfortably warmer in summer, and the AC runs less effeciently.

2 summers ago, I purchased 18 sheets of R Matte Plus 3 aluminum-sided foam sheathing from Home Depot, for about $8 a sheet.  I placed them shiny side up on the flat portion of the roof. The panels are weighed down with strategically placed bricks. In the fall, I stack the panels up in the center of the roof, cover them in a tarp, and weigh the stack down with the bricks. To deploy or stack the sheets takes only about an hour. 

I know the panels may well blow off in very high winds, but the home is in a valley and surrounded by high trees, so the odds are with the panels. This scheme has reduced my home cooling costs considerably, and has equalized the upstairs temperature to the downstairs in summertime. I wish I had started doing it 20 years ago!