Radiant barrier sheathing panels have two sides: a foil surface and a skid-resistant surface. LP TechShield panels should always be installed with the foil side down and the skid-resistant side facing up. Be sure to wear skid-resistant shoes during radiant barrier sheathing installation in a roof application.
Radiant barriers that are reflective on one or both sides may be used with any of these locations. However, if the radiant barrier is reflective on only one side, the reflective side must face toward the main attic space for Locations 1 and 5.
if it is hot outside, the reflective part of your foil insulation must face outside. if it is freezing outside, the best orientation of the reflective part is inside. if you press the foil side of the insulation tight up against the wall (foil facing outward), the radiant barrier will not work.
(Most Reflectix® products are reflective (shiny) on both sides.) The reflective insulation benefit is derived from the interaction of the highly-reflective surface with the air space.
Installing it
No air space means no thermal value. The reflective side must be facing downwards when in roofs, upwards when installed underneath a floor and inwards when installed in walls.
Vapor Barriers
The facing of the insulation serves as a vapor barrier. Vapor barriers resist moisture penetration, keeping humid interior air from reaching cold surfaces where it could condense. In cold climates, vapor barriers go on the warm side of insulation. In hot, humid climates, they go on the exterior side.
With standard and heavy duty foil, it's perfectly fine to place your food on either side so you can decide if you prefer to have the shiny or dull side facing out. For Reynolds Wrap® Non-Stick Aluminum Foil, you'll want to have the dull side facing up.
Roll out the product across the top of the trusses, pull tight and staple at approximately 4” intervals. Run subsequent courses of the product with the 3/4” staple tabs overlapping at the seams. Tape the seams with a Reflectix® Foil Tape (goal is an air-tight, snug seam seal). Install purlins over the insulation.
This unique material can reflect up to 97% of radiant heat.
A radiant barrier reduces the radiant heat transfer from the underside of the roof to the other surfaces in the attic. A radiant barrier works best when it is perpendicular to the radiant energy striking it.
(The general rule for insulation is that the facing always goes toward the conditioned space.)
The fibre side is laid in contact with the ceiling. If you were creating a warm attic by insulating between rafters, then you would want little temperature difference between the inside insulation surface and the room. So the foil side should face the slates and the fibre side the attic space.
Radiant barrier sheathing panels have two sides: a foil surface and a skid-resistant surface. LP TechShield panels should always be installed with the foil side down and the skid-resistant side facing up.
Radiant barriers are single sheets placed facing air spaces to reflect solar radiation and heat. Reflective insulation uses multiple layers and air spaces to create a thermal barrier that resists conductive, convective, and radiant heat flow.
The tests to date have shown that in attics with R-19 insulation, radiant barriers can reduce summer ceiling heat gains by about 16 to 42 percent compared to an attic with the same insulation level and no radiant barrier.
If you're wondering whether to put the foil side of foam insulation board shiny side in or out, consider whether you want to make the space inside warmer or cooler. If you want to make the space warmer, the foil should face inside so it can reflect radiant heat back into the room.
This is because an air gap provides an additional layer of insulation that helps to prevent heat from passing through the barrier and into the living space. If you are installing a radiant barrier, it's recommended to leave an air gap of at least 25mm (1 inch) between the barrier and the surface it's installed on.
When the paint is installed correctly, it will reflect about 75% of the radiant heat and can be a very good product. Getting good results with radiant barrier paint assumes a couple of things: The rafters are being sprayed completely (this usually costs more when you get an estimate).
Though there is a difference in how much heat the shiny vs. dull side reflects or retains, measured over time and considering the type of heat the oven emits, that difference is negligible and has little to no discernable impact on the food. That's why it doesn't matter which side you use.
How do I know which way to put my material into the machine? You will see one side is shiny and the other side is matte on your iron-on material. The shiny side is the liner backing. This needs to be facing downwards so that the matte side is being cut by your machine.
Vapor barrier materials are installed on the warm side of the insulation in a building assembly, as determined by climatic conditions. In warm climates, it will be on the exterior and in cold climates, it will be on the interior.
Begin at one side of the crawl space and lay down 6-mil or thicker polyethylene plastic over the entire crawl space. Cut the sheets to size, allowing 6 inches or more along walls. Overlap the seams by no less than 12 inches and secure them together with the poly PVC tape.
Installation Tips
Here are a few tips to get you started: Direction Matters: The vapor barrier should always face the warm side of your insulation. In the UK, that's usually the inside of your building.