Rigid Board Insulation vs. Prodex Total Insulation - an alternative to Rigid Board Insulation
Definition: Lightweight thermal insulation, such as polystyrene. It is use where structural strength is not an issue. It is manufactured in a rigid or semi-rigid form. It can have a finish side or be used under a finish material. R-value 6-7 per inch.
Alias(s): foam board , rigid foam insulation, board insulation, foam board insulation, rigid foam board insulation, polyisocyanurate, polyiso board, polystyrene, rigid foam insulation.
Rigid board insulation problems:
Rigid board insulation does not prevent radiant heat transfer (The primary source of heat-flow in and out of your structure). Expensive, r-value diminishes slightly over time especially if the foil face is removed. It will absorb moisture if wet, degrades in sunlight. In cold weather, warm inside air containing water vapor can get past the wall finish and insulation, condensing inside the colder wall cavity. In hot, humid climates the same thing can happen, just in the reverse direction. Humid outdoor air in the summer can condense inside cool, air conditioned wall cavities. If enough of this happens and the water cannot escape, wood rot, mold, and other moisture-related problems can occur. Reflective insulation board is an improvement, but it only has one reflective surface and therefore lacks the ability to perform like a double sided reflective insulation.
When insulating a foundation you need to consider that, although insects don't eat foam board, they can easily tunnel through it. Insect burrows reduce the r-value and structural integrity of the insulation. For these reasons, some manufacturers treat their insulation board products with an insecticide, usually a borate compound. Many building jurisdictions also mandate treating the earth around the building with insecticides. These jurisdictions may also want an inspection area several inches wide and all around the foundation of a house kept bare of insulation board.
Alternative to Rigid Board Insulation: A better insulation product would provide a radiant barrier, vapor barrier and provide more R value. It would also provide some elasticity to make installation easier.
Prodex Total Insulation = reflective insulation + radiant barrier + vapor barrier ALL in One Product!
Prodex Total Insulation is a radiant heat barrier (Reflects 97% of radiant heat (the primary source of heat flow). It is a vapor barrier (0.033 gr/m2hkPa) and it is a reflective insulation R value 15.67. Prodex has a high yield point, which means it's considered elastic -- It can be stretched during installation. That also adds the benefit of a clean look once installed. It is composed of 5mm (13/64) closed cell polyethylene foam sandwiched between two reflective, low emissivity surfaces. Rather than board it's an insulation roll.
Compare PRODEX Total to: