Super Insulating Shell

The Making of a High-Performance Super-Insulated Exterior Wall Retrofit

1. First, a liquid-applied air and water control membrane (Black Peel and Stick/Ice and Water Shield, 60 mil - around windows & penetrations; & Grace Perm-a-barrier VP – painted on the building surface: ) is actually painted onto the exterior of the building’s original brick walls. This layer provides a water control surface to keep any water that gets behind the insulated panels from continuing into the building. This layer also stops air from leaking into and out of the building – air actually leaks through untreated brick and concrete block walls! A little known fact is that without air sealing to stop leaks, insulation doesn’t work very well. Not air sealing is like wearing a sweater (insulation) outdoors on a cold day. You’re cold until you put on a windbreaker (air sealing).
2. Then a mineral fiber air flow suppression layer is added. This layer is made of mineral fiber insulation to also stop air movement. The exterior cladding system (which is installed last) has small openings or “weeps” designed to drain water out of the assembly. While it is important to have a way for water to drain, it is not desirable to have wind blowing behind the major insulation component. Also, since the air behind the insulating panels will be significantly warmer than the outside air during the winter, there is a natural tendency for the “chimney effect” to move air through the space behind the insulating panels. Uncontrolled movement of air behind the insulating panels could largely negate the benefit of all that insulation. The fibers of the mineral wool insulation are packed densely enough to significantly reduce the “chimney effect” as well as the effects of small air pressures acting through the weep holes. A very important property of this material is that the fibers allow liquid water to drain through to the weep holes, so the panels can continue to drain water, without a lot of air leakage.  Because mineral wool is made of rock, it presents no additional fire safety concern.
3. Lastly, insulated metal panels (Kingspan Panels) are installed on top of the mineral fiber. The insulated metal panels consist of rigid foam high density insulation material within a thin sheet of metal laminated to each side. The insulating metal panels are multi-functional – they provide insulation, shed rain water and snow, and provide the aesthetic finish for the building. The insulated metal panels will provide a durable finish system. With the R-41 rating, the 5” panels provide the “super insulation” to the high-performance super-insulated wall assembly. The effective insulation performance achieved is twice that of wall systems built to current code.