Thermal bridging accounts for up to 30% heat lost in residential buildings and heat gained in metal buildings. With ONE very simple installation application, 3 layer (multi-layer) bubble foil radiant barrier, not only can the thermal insulation be left out of the install but the thermal bridge can be broken when placing the last layer under the rafters or truss attached to the spacers. This applies to both homes and metal buildings.
With 3 layers (remembering R = trapped non-moving air), the three layers sum to an R value of R-48. That is without thermal insulation! Wow.
In exterior walls, wood, metal and concrete act as thermal bridges conducting more heat than the insulation on either side of them. If you are one of the unlucky ones to live in a home with metal studs with fiber glass batting in the cavities, the studs will reduce the overall R-value performance by up to 70% or more! According to Building Science Corporation, “The R-value of 6-inch deep steel studs installed at 16-inch centers with cavity insulation of R-21, is reduced to R-7.4. This is a 35% decrease and that does not include siding or other conductive building materials which, will reduce the R-value even more. In some States, it is becoming law to address thermal bridging in construction. We are finding it is now code and or, becoming code in many areas. Thermal bridging affects energy performance, health and durability of the structure because it causes cold spots which, creates a condensation risk. Beyond heat loss and comfort and air quality and structural integrity, there is mold, mildew and rot.
We still must insulate the exterior walls and stud bays but what must change is the product or material used. This is where radiant barrier bubble answers the call. As proven with a cold storage walk in facility where our product was used in a multi-layer application, thermal insulation was unnecessary.
Taking this application a step further, the thermal bridge can be broken in a large walk-in cold storage facility (metal) using the multi-layer system and placing the last layer across the metal on spacers to incorporate the metal structure into the radiant barrier envelope. Thermal bridges causing significant heat loss are not limited to just the studs in a wall, metal or wood. Corner junctions, discontinuous insulation, concrete slab junctions at walls, balconies, service openings and penetrations where metal I-beams pass through wall assemblies.
Putting insulation between studs is like trying to stay warm by eating a down jacket. IF you address the radiant heat using radiant barrier in a triple layer system AND break the thermal bridge, thermal insulation is not needed. One product using a multi-layer application will solve 3 problems at once. The product solves the heat issue, the thermal insulation issue, vapor and then with the right installation technique for the last layer, solves the brutal thermal bridge.
Thermal bridges exist today because the building envelope is getting more and more airtight and more insulated. In older construction, buildings were not sealed up like a drum and construction methods for stone walls were 100% different from how we build today with wood or metal skeletons and wall cavities.