Fiber Cement Siding R Value

For instance if you have a material with an r value of 12 attached to another material with an r value of 3 then both materials combined have an r value of 15.

Fiber cement siding r value.

As we said before the r value measures the thermal resistance of a material. That s a little less than you ll get from vinyl siding which is rated as r 0 61 but the. When vinyl siding is optionally insulated it can achieve r 2 values and even greater. Most siding including fiber cement have an r value of less than 1 when installed alone with out additional layers or types of insulation.

If you choose fiber cement siding for your project then the r value of the product is only 0 5. Asbestos cement board r value. This beats fiber cement which has an r value of 5 at most. Underlayment material even a foam board doesn t offer much extra and would be applicable to both materials.

Adding foam back vinyl siding leaves fiber cement in the dust as that has at minimum 1 8 r value. While fiber cement siding is energy efficient vinyl siding has the potential for this too. Because vinyl siding is thinner than fiber cement siding it can better accommodate insulation beneath its surface. Asbestos lagging and paste will have a lower value.

Fiber cement siding doesn t add much insulation to your wall system measuring in at a mere r 0 50. Adding inch of rigid foam insulation r 2 in this example will increase a 2x6 stud wall from an effective r 15 to an effective r 17. Esr 1844 noncombustibility see page 1 section 3 1 flame spread and smoke developed see page 1 section 3 1 1 hour fire walls see page 2 section 4 3 design wind loads see page 4 5 table 4 r values see page 3 table 2. Thermal conductivity k 0 15.

Hardiepanel siding cempanel siding. Standard vinyl siding has an r value 6. According to table 5 1 of the ashrae fundamentals handbook fiber cement has an r value of 15 better than brick and stone but lower than vinyl at r 60 wood at r 81 and insulated vinyl siding at r 2 0 3 5. This is an increase of 13 of effective thermal resistance.

Foam thicker than a half inch will yield even higher r values. Asbestos cement shingle siding. R value see table 2. This means as a stand alone product fiber cement isn t going to add much insulation to your home.