Min R 42 Cellulose Roof Insulation

As i see it the biggest reason that code asks for more insulation than r 40 is that the testing for insulation is faulty and doesn t represent real world temps.

Min r 42 cellulose roof insulation.

Know exactly how much you need with our project calculators. 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. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. The higher the r value the greater the insulation performance.

Injection foam insulation s higher r value. Does your home have enough r value. A recent mckinsey co. The higher the r value the better the thermal performance of the insulation.

This calculator is to be used as an estimating tool only. Insulation level are specified by r value. This reduction of insulation from the. As a benchmark one inch of solid wood has an r value of 1.

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. When determining how much insulation you need don t guesstimate calculate. Minimum insulation r value requirements non residential above roof deck. Click the button to calculate the approximate r value for this job.

The table below shows what levels of insulation are cost effective for different climates and. For a ceiling without an attic space like a cathedral ceiling where the insulation requirement is greater than r 30 and the design of the roof ceiling assembly does not allow sufficient space for the required insulation the minimum required insulation for such roof ceiling assemblies shall be r 30. R value measures how well certain building insulation materials can resist heat. With an r value of 4 0 to 5 1 per inch depending on the manufacturer pre expanded injection foam provides a higher r value than fiberglass or cellulose and it seals the building from air leakage at the same time.

R 60 u 0 016 or 80btu per hour in the above example if you graph this info you can see that after you reach an r 40 the drop in heat transfer is minimal as more insulation is added. State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2 r 20 3 r 20 state local mo missouri 2012 iecc 4 r 25 5 r 25 state only mt montana 2012 iecc 6 r 30. Injection foam insulation stops air leakage. R value is a measure of insulation s ability to resist heat traveling through it.

Input depth of existing blown in insulation in inches.