DIY Reflective Insulation Sheet vs K-Flex Elastomeric Insulation Sheet

Buy the DIY Reflective Insulation Sheet for windows, garage doors and RVs, where reflecting radiant heat matters most. Buy the K-Flex sheet for ducts, tanks and pipes, where a thick closed-cell rubber sheet with a pressure-sensitive adhesive backing wraps and seals. The reflective roll is thin foil-faced foam and reflects most radiant heat, but owners report the included pads fail to hold it up. The K-Flex is a denser elastomeric sheet with a real adhesive backing and a plenum rating, but it is black, opaque and not a radiant barrier.

• Choose the DIY Reflective Insulation Sheet if you need to block sun and radiant heat at a window, garage door or van panel and want a light, trimmable roll.
• Choose the K-Flex Insulation Sheet if you are insulating ducts, tanks or vessels and need a thick, plenum-rated sheet that sticks on with its own adhesive backing.