Compare Insulation R-Values

The main purpose of insulation in a home is to reduce or prevent heat flow. Remembering that heat always goes to cold, heat flow, or transfer of heat, occurs when it's cold outside and the heat escapes from your home. And when it's hot outside the heat comes inside. Ultimately, the goal is to maintain a comfortable living environment while saving energy and ultimately money.

When comparing insulation R-values *, it's important to understand that not all insulations are alike. Some wall and roof insulations are better at resisting heat flow than others. Consequently, they have a higher resistance value or "R-value". The higher the R-value the better resistance and less insulation thickness is required to achieve the insulating effect you desire. The chart below can help you compare some of the more common materials and approaches to insulating homes along with their corresponding R-values. 

With most types of insulation, as the temperature drops the R-value increases, but some perform much better than others.  It is important that, when you compare the R-values of different insulations, you know at what temperature the product was tested. In the US, the apples-to-apples R-value standard is ASTM C518, and the test results are reported at temperature of 75°F. In colder climates where your heating costs are high, you might be more interested in the insulation's R-value at maybe 60°F or 40°F or maybe even 20°F, but for this comparison chart, RAYCORE will use the ASTM C518 Standards at 75°F.

It does to RAYCORE and it should to you too! 

Cost & R-value - Most sandwich panel suppliers price their panels by thickness, not R-value. Unless you specify to them a particular R-value, most likely you will be quoted for a 6 1/2-inch thick panel. Most pre-prepared sandwich panel SIPs house plans will specify a 6 1/2-inch-thick panel.  There are reasons this panel is most commonly specified and quoted. Ultimately, it all comes down to cost. RAYCORE's 5 1/2-inch panel is almost twice the R-value and could be half the price of the sandwich panel SIP.

Sandwich panels are competing with other insultations and types of panels. These types of panels are generally 2 to 3 times more expensive than other insulations. The thinner the panel, the lower the price. A 6 1/2-inch thick EPS sandwich panel has an R-value of 24. RAYCORE's 5 1/2-inch thick polyurethane SIP panel has an R-value of 42. That's 75 percent more R-value for half the price!  To reach a similar R-value with a sandwich panel, you would have to purchase their 10 1/4-inch thick panel with an R-40 or their 12 1/4-inch thick panel with an R-48 insulation value. If the 6 1/2-inch thick sandwich panel costs 2 to 3 times more, how many times more do their 10 1/4-inch or 12 1/4-inch thick panels cost to achieve a similar R-value?

Secondly, the thicker the panel, the greater the cost of almost every material associated with closing in the outside walls and roof of the house. These materials are not included in the sandwich panel package. Thicker panels mean larger framing materials for top and bottom wall plates, windows and doors framing, roof framing, fascia and more. All sandwich panels result in a nonstandard wall thickness. Your windows and doors will all need expensive window and door jamb extensions or special materials and labor to trim them out on-site. The thicker the wall, the greater the cost. 

RAYCORE SIPs use standard framing materials, standard roof framing, facia and more. Window and door jambs are standard, so never any added cost.