R-Valued Homes (RVH) SIP buildings are manufactured and fabricated exclusively with polyurethane (PUR) foam because of its superior qualities over expanded polystyrene (EPS) foam, for example:


  • PUR foam has double the R-value per inch of thickness (PUR –R8 @20°F v. EPS –R3.85).

  • PUR foam has a Class 1 fire rating with a flame spread of 25 and a smoke spread of 350.  PUR will not burn without a continuous flame exceeding 750°F; at lower temperatures, it will only char.  However, EPS will melt at temperatures ranging as low as 180°F to 240°F.

  • PUR is closed cell foam and is impervious to moisture with a perm rating of less than one (1) which classifies it by definition as a vapor barrier; however, EPS is an open-celled structure and will absorb up to 4.3% of its volume in moisture.

  • PUR foam is not a volatile organic compound (VOC) and therefore does not contribute to ozone depletion whereas, Styrene, a chemical component, of EPS, has been added to the US Health Dept. list of carcinogens.

  • PUR foam will not support mold and mildew.

  • PUR foam does not contain any formaldehyde.

  • PUR foam does not support nesting by vermin.

  • PUR foam SIPs qualifies as a LEED/ GREEN building product.

  • PUR foam is glue with superior adhesion and excellent tensile strength.


RVH energy-efficient SIP buildings provide the homeowner or builder with a multitude of benefits and, at its most basic level, provides the Cadillac of Insulation. RVH SIP buildings are proven to be energy-efficient, environmentally friendly, and are changing the face of construction throughout Alaska and the Yukon.


Moisture is easily one of the biggest concerns for builders and homeowners. A home that has excess moisture will promote the growth of biologic pathogens such as molds, mildew, fungi, and bacteria. The challenge homeowners face with moisture problems is that they are not always visible to the naked eye. Condensation may form inside wall cavities where vapor barriers have failed or were incorrectly installed, creating the ideal environment for decay and mold growth, not to mention structural damage. This can lead to upper respiratory problems, asthma, and potential allergenic reactions.


RVH exterior SIP envelope prevents the silent absorption of moisture through the panel membranes. Polyurethane foam SIPs have a perm rating of less than “1” and are a moisture barrier; therefore, moisture absorbed by the panel skin is drawn out by the warmer surface temperature.  Homeowners can rest assured their home is dry, free from mold, mildew, and possible structural damage. A dry home is a healthy home.

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