Polyurethane Vs. EPS (Expanded Polystyrene)
Polyurethane is a relatively new product, roughly around 35 years. EPS has been with us for around 60+ years. Polyurethane was produced to replace the shortfalls of expanded polystyrene. Below you will see a detailed difference between polyurethane, and expanded polystyrene.
R- Value - Polyurethane is one of the highest rated insulation materials in the world. You will find it in most all of your refrigerators, freezers, soda vending machines, and even in your personal carry about coolers. Per inch of insulation, polyurethane has no equal. EPS has a value of R-2 to R-5 per inch.
POLYURETHANE HAS AN R-VALUE OF R-7 TO R-8 PER INCH. How much value do you put on saving money heating or cooling your home?
Moisture Resistance - With all the recent problems of mold and mildew in walls, moisture resistance today is a very important factor. Polyurethane is a closed cell foam insulation product and has one of the lowest moisture permeability ratings of any product manufactured for use in the building industry today. The tested permeability rating on our polyurethane is 1.2. The permeability rating on EPS is 2.0 to 5.0
This difference in a high humidity area would warrant another moisture barrier for EPS panels. But, in some cases this can lock in moisture that can lead to mold growing inside your walls.
Fire Resistance - The polyurethane that we use is a UL Class 1 rated foam. This means that our polyurethane is not a source for fire. On its own, our polyurethane will not burn. A Class 1 rating is the highest rating a building product can obtain. Also, polyurethane is a thermal-set plastic. This means, that it will not melt. Our polyurethane is not affected until temperatures reach 1000 degrees and at that time it will only char. EPS on the other hand is not a thermal-set plastic and will begin to soften at temperatures above 180 degrees, and melt at temperatures of 240 degrees. Polyurethane has a distinct advantage.
DENSITY - The density of a product will determine the strength of it. EPS has a density of 1 lb. The polyurethane that we use has a density of 2.2lb. Advantage: polyurethane.
CHEMICAL RESTANCE - Polyurethane is resistant to most over-the-counter chemicals. EPS reacts negatively to petroleum based products. PL 400 and liquid nail will literally burn thru EPS.
MANUFACTURING - Probably the biggest difference between Polyurethane and EPS is in the manufacturing of these panels. Both products use OSB for covering both sides of their foam, but here is where the similarity ends. In the bonding of the foam to the OSB we use the polyurethane itself. Polyurethane is one of the best glues used in the industry today. Some manufacturers of OSB and plywood use polyurethane to bond their products together. When it comes to adhering, the use of polyurethane gives us both an excellent R- value and the strongest bond in the industry. EPS panels use glue spread on both sides of the OSB, and then the OSB is matched together with the EPS, and mechanically held in place under pressure until the glue is dried.
One can understand why there are so many more EPS manufacturers than Polyurethane. We feel that the plant equipment investment we made provides today’s builders with the product they need to keep customers satisfied both in the short term and long term. We believe that there is no comparison between our panels, and those of EPS manufacturers. We by far offer a superior product for today’s marketplace.
The age-old proverb is still true today. YOU USUALLY GET WHAT YOU PAY FOR. Is saving a few dollars really good economics when you are building something that will last a 100 years?