This website has not been optimized for mobile devices.  Please view on Desk/Laptop computers.

  After 9 years,
Time to RETIRE!  All prices reduced 10-20% to clear out remaining stock


In an effort to hasten the clearing of my last warehouse, ALL PRICES HAVE BEEN REDUCED 10-20%
From a high of 6 warehouses, only one is left and it is running low.
 THANK YOU !  to all my great customers over the years

  • My last shipment of material from the factory was January 2014 as they upgraded their equipment and no longer produce non-compliant insulation sheets.  When this remaining material is sold out, I will finally get to fully retire!

    This material is in South-East IDAHO (83241) and shipping more than a few hundred miles gets quite expensive.    More than 1000 miles is totally uneconomical.

  • For INVENTORY and PRICES, click on the "INVENTORY & PRICES" link at the top of this page.

How I got into this enterprise....

For many years my family has stored provisions to hedge against natural disaster and other unforeseen events.  Food, water, medicines and other staples were fairly easy to accommodate within a residential setting.  But fuel for heating or electric generation was fraught with problems: fire safety, sheer quantity, and storage life being the worst.  After considerable research and experimentation I determined that if the house structure was insulated sufficiently the energy requirements to keep it comfortable could be reduced - even to almost zero.  An added benefit was that this method PAID FOR ITSELF over very few years in heating/cooling cost savings, and would become incredibly important should energy become unaffordable or unavailable due to natural or manmade disasters.  Google search “SUPER INSULATE” for more information.

Additional research then led me to this type material since it has the highest and most stable R-Value-per-inch-of-thickness (R-6/inch) of any insulation material commonly available.  See HERE and HERE for good discussions of insulation materials.  A standard 2x4" wall using the common pink or white fiberglass batting has an R-13 value.  With the Poly-Iso insulation, that same 2x4" wall becomes R-23, which is even higher than a 2x6" wall using fiberglass batting( R-19).   With Poly-Iso that 2x6" wall jumps to R-35.   And being in a lightweight, rigid sheet form which is easily cut to fit between framed walls and rafters and glued to concrete walls, I knew I could install it myself, saving additional money.

One bad thing:  The cost of new Poly-Iso is quite expensive.   So to get the best price I bought the entire inventory of “over-runs” and “seconds” Polyisocyanurate insulation material from a large insulation manufacturer to use in my house, shops, potato cellars, and other out-buildings here in South-East Idaho.  I had more than I needed to finish my projects and sold off the surplus.  Then up until February 2014 I was able to buy additional material. I am quickly selling out of my remaining inventory, and at current rate of sales should be sold out in either 2018 or 2019.


This material comes in 4 foot by 8 foot (4’X8’) or 4 foot by 4 foot (4'X4') rigid insulation sheets in many different thicknesses/R-Values.  Typical R-Value is about R-6 per inch of thickness.  It has 15-25% better insulation R-value per inch thickness than expanded/extruded polystyrene or other similar materials found at the big-box home improvement stores. And unlike Polystyrene or Polyurethane, which are "thermoplastic" materials, Polyisocyanurate is a "thermoset" product that will not soften or melt at elevated temperatures - a significant advantage to limit flame spread in a fire (See HERE for more details).

If you don’t find the exact thickness you want, the same R-Value is achieved using multiple layers of thinner sheets.  And the cost will be the same since the material is priced by the cubic foot- not square footage.  IE: if you need 5" thickness of insulation you can stack two 2.5” sheets and achieve the same R-Value as a single 5” sheet would provide and the cost is the same as using a single 5" sheet.

This material is useful for insulating homes, basements, shops, overhead doors, trailers, metal buildings, wood frame or concrete buildings, concrete floors/walls, greenhouses, animal shelter/barns, water pump/tank/well enclosures, and many other spaces where the highest R-Value-per-inch-thickness is desired (See the Picture Gallery page for more details and installation ideas)


Most material is sold by the bunk.   A "bunk" is a bundle of material that measures 4'x4'x8' in size.  The number of sheets in a bunk is determined by the sheet thickness.  Since a bunk should be 48" (4') in height, only enough sheets are stacked up to get as close to that height - rounding down as needed.  Thus a bunk of 1" sheets would consist of 48 sheets, while a bunk of 2" material would have 24 sheets.  Please see Product/Pricing Info page for details.  But no matter how much you purchase, the price-per-sheet will be far less than what the home improvement stores charge for equivalent products.

The square-footage per bunk will vary depending on the thickness/number of sheets in the bunk.  Individual bunks contain one material size and thickness only.  Refer to the table in the Product/Pricing Info page for number of sheets and square footage per bunk data.

These insulation sheets consist of a closed-cell polyisocyanurate foam insulation core with thin 'facer' material laminated to both sides.  The facer material provides tensile strength to help resist breakage the same as the paper facer on both sides of a sheet of gypsum board.  The facer does not contribute meaningfully to the insulation R-Value. Most of my inventory has a cellulose fiber (paper) with embedded fiberglass strands facer, which is much like a heavy-duty version of the construction-paper your teacher gave you in Elementary School.  It is the least expensive type, and the lightest, but it can be compromised or cause the sheet to warp if exposed to water. The other type of facer is a glass fiber and resin material that is immune to the effects of moisture, but makes the sheets 20-25% heavier. This material is designated Resin (R) in the Inventory and Prices tables and does cost more, but is far superior for applications in a wet or high humidity environment.

SECONDS are sheets that were pulled from the production line by the Quality Assurance inspectors for visible irregularities such as cosmetic defects, interior/edge pockets and/or voids, irregular or rough edges, out-of-tolerance dimensions, etc.   SECONDS bunks are not packaged in bags as the OVERRUN material is. 

OVERRUNS usually appear factory-perfect, however they still do NOT meet one or more of the intended design specifications. Some reasons I've seen for these failures are CORE DENSITY, COMPRESSIVE STRENGTH, FACER ADHESION, or some other of the tests that are done after they've already made it through the STACKING/BAGGING/MARKING stage. That is why OVERRUN bunks come packaged in the factory-original heavy-duty white shrink-wrap bags whereas SECONDS do not.  And although of a higher physical quality than most “SECONDS”, they ALSO COME WITHOUT WARRANTY OF ANY KIND(See Warranty Disclaimer page)

ONE LAST POINT:  This material was designated NON COMPLIANT by the manufacturer and as such has no brand markings on the sheets or packaging. SPECIFICATION SHEETS or FACTORY CERTIFICATIONS ("CERTS") are not available should any authority having approval rights over your project require such documentation.  And since Zinsulation does not accept returns, know your applicable building codes and inspection/approval requirements before buying this material!


Call my cell: 8Ol-7l7-589O or email for further information. 

  Back to top

PS: I'm a "retired" old fart and put this cheesy web site together myself.   (Zinsulation has 1 employee: me)

Website Builder