Dear DuckGuy: A radiant / reflective barrier like Reflectix is not a good solution, because cold cannot be 'reflected' and the wamer air inside your steel shed is not 'radiant' (emitting lots of infrared energy). The best solution for your shed is 2" thick Foamula XPS foam board. This will provide R-10 insulation, plus XPS does not absorb water and can be hosed down if you need to clean the surface. You can fasten the foamboard panels to the metal walls and roof with Loctite PL-300 glue, which Home Depot carries. Also be sure the seal all of the joints and perimeter to block air leaks. DAP 230 or HVAC mastic are good for joints and small gaps. Use the 'Window and Door' version of Great Stuff spray foam for larger gaps. Insulation performance is measured by thickness, so there is no effective solution that will not require space --- and XPS foam board is the best option. Also note that foam board is flammable -- so be careful with the placement of your radiant heaters. You may need to insulate / isolate the back side from the foam board, e.g. with a rock wool batt. I hope this is helpful. Mark
Dear Liska: Radiant / reflective barriers like Reflectix do not work well in winter or cold climates because cold cannot be 'reflected' and the warmer air inside your home is not 'radiant' (generating lots of infrared energy). The only effective solution is standard insulation, e.g. foam board, rock wool and blown cellulose for attics. Home Depot carries all of these products, and most can be installed by the average homeowner. Also read-up on the Web on how to insulate and air-seal a home. There are lots of good resources online, e.g. Fine Homebuilding and Green Building Advisor, with excellent advice and tips from professionals. Air-sealing is almost as important as insulation R-value, and moisture control to prevent rot is a key issues in colder climates. I hope this is helpful. Mark
Dear JC: First, Reflectix is not designed for exterior applications. Second, it would provide no insulation benefit. Reflectix and similar reflective / radiant barrier products deliver very little insulation by themselves, just R-1 for Reflectix. You must build a sealed or vented air gap to achieve the claims on the package. Third, Reflectix and similar products do not work during the winter because cold cannot be 'reflected' and the warmer air inside your shed is not radiant. So, standard insulation products from Home Depot are much better solutions, winter and summer -- e.g. foam board and rock wool batts. Also remember to insulate the floor; Foamular 250 foam board has enough 'compressive strength' to be installed on the floor, then covered with 3/4" plywood as your subfloor or walking surface. I hope this is helpful, Mark
Yes it will help
Dear AT: Yes, this is one of the best applications of a reflective / radiant barrier product like Reflectix. Independent testing shows that it will reduce the heat flux from a hot roof in the summer to rooms below by ~24%, which can reduce your HVAC costs by ~3% to 4%. Note, however, that reflective / radiant barriers are not effective during the winter because cold cannot be 'reflected' and the warmer air inside your home is not radiant (emitting infrared radiation). So if you want to improve the insulation in your attic for winter and summer, you need to add standard insulation, e.g. blown cellulose, which is ideal for attics. Home Depot sells Green Fiber cellulose and rents blowers to install it. If you have a question about how to install blown cellulose, please post it on the page for the Green Fiber product. I hope this is helpful.
It has small holes to be breathable- wd use the bubble wrap type of reflectix
No! It is aluminum over Mylar sheet.
Dear Mac: Reflective / radiant barriers like Reflectix provide almost no insulation R-value by themselves, just R-1. The claims on the package are based on a sealed air gap that you must build; this air gap is responsible for almost all of the R-value. You have the right idea, but foam board is the right solution under your new metal roof. Use Foamular XPS foam board, which does not absorb water. 2" thick Foamular 250 will provide R-10 insulation. I hope this is helpful. Mark
No, and why?
Dear AT: Reflective / radient barrier products like Reflectix deliver almost no insulation R-value by themselves -- just R-1. The claims on the package are based on a sealed air gap you must build / create when you install it. This aif gap is responsible for almost all of the claimed R-value. It would be impossible to create an air gap inside your car doors, and Reflectix will be almost worthless if you simply glue it to the metal surface. Closed cell foam would be effective, but difficult to install with the window mechanism in the middle of the door. I hope this is helpful, Mark