R Value Of Fiberglass Roof Insulation

A rigid roof insulation board with high thermal efficiency johns manville r panel is compatible with multiple types of membrane systems.

R value of fiberglass roof insulation.

What r value do i need. The common denominator among varieties of insulation is the r value. You should of course see the manufacturer provided technical data sheet for the r value of specific products. Know exactly how much you need with our project calculators.

R value is used in the united states. R value measures how well certain building insulation materials can resist heat. To convert rsi to r value multiply the rsi by 5 67826. Our r value guide to rigid insulation includes the doe s recommended insulation by zone chart r value calculator and base building material r values chart.

The higher the r value the better the thermal performance of the insulation. Rsi r value système international is the metric equivalent. R value of various materials. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1.

Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. I calculate insulation resistance to heat loss or r percentage improvement always as relative to the original number. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. Open cell polyurethane spray foam 3 5 inches.

The higher the r value the greater the insulation performance. The increase r21 r3 exactly 18 the value by which you are increasing the r value. Insulation level are specified by r value. R panel is manufactured with a closed cell polyisocyanurate foam core bonded to fiberglass reinforced facers and designed for use over metal nailable and non nailable roof decks with a variety of membrane systems.

The percentage increase increase increase original number 100. Recommended home insulation r values. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. R value is a measure of insulation s ability to resist heat traveling through it.

Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. As a benchmark one inch of solid wood has an r value of 1. The table below shows what levels of insulation are cost effective for different climates and. When determining how much insulation you need don t guesstimate calculate.

See the department of energy s doe ranges for recommended levels of insulation below. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7. Input depth of existing blown in insulation in inches. Loose fill such as fiberglass cellulose mineral wool 8 23 inches thick 30 50.

Click the button to calculate the approximate r value for this job. This calculator is to be used as an estimating tool only. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826.