Foil Bubble Insulation Under Metal Roof

The main one in the latter category is foil faced bubble wrap sold as insulation.

Foil bubble insulation under metal roof. A secondary method of installation instead of installing under the attic rafters is to lay the foil insulation over the attic floor. Foil insulation underlayment is recommended under a metal roof and in most cases the shiny side should be facing up but there s a catch. Most brands of foil faced bubble wrap are only 3 8 inch thick or less and have an r value of only 1 0 or 1 1. Since the product often costs more per square foot than 1 inch thick rigid foam rated at r 5 why would anyone use bubble wrap as insulation.

There is no contained air gap inside the foil and the air gap outside the foil is fairly leaky i don t think that there will be much benefit from the insulation value of the bubble wrap. When i wrote about my trip to the southeast building conference in july i mentioned how some products on display there really annoyed me because they re either bad to the bone or overhyped. The r value of foil faced bubble wrap is so low that it has few if any advantages over rigid foam. This is why we recommend ecofoil bubble insulation for most metal building applications.

Green building advisor recently wrote an article about foil faced bubble wrap and did a balanced job of it. Looking at the table of insulation values bubble wrap and foil will have limited benefit on reducing heat loss. Attach it to the purloins with double stick tape to hold it in place until you. Achieved by attaching to the underside of 2 x 4 roof purlins creating a 2 enclosed air space between bubble insulation and metal exterior roof.

It s important to know that ecofoil bubble insulation can absolutely be used in conjuction with other forms of traditional insulation for a combination to work against all 3 types of heat transfer. This insulation performs exactly the same as ecofoil double bubble foil insulation the white is just a cosmetic difference.