Recommended Insulation Depth For Attic

The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type.

Recommended insulation depth for attic.

Rigid foam boards trap air or another gas to resist conductive heat flow. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. Inspecting your attic insulation. Insulation levels are specified by r value.

Mary previously had 100mm of fibreglass insulation in her attic but decided to upgrade the insulation in her attic to the required 300mm following consultation with the seai and various contractors. Once this layer has been laid then lay 170mm insulation across the top of the joists at 90 degrees to the joists. Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. Insulation level are specified by r value.

Both can be added to uninsulated attics or layered over existing material. Once you ve decided which type is best for you examine the material options and prices to home in on the right product. Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live. For diy attic insulation you ve got two choices.

These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Recommended home insulation r values. R value is a measure of insulation s ability to resist heat traveling through it. Attic insulation using fiberglass mary has a four bedroom detached house 150m2 in size.

For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed your attic to reach r 30 if you live in zones 2 or 3. The reason for this is that the insulation manufacturers are trying to make it easier to hit the 270mm thickness sweet spot. In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended. Insulation materials run the gamut from bulky fiber materials such as fiberglass rock and slag wool cellulose and natural fibers to rigid foam boards to sleek foils.

For loose fill cellulose this translates to a total depth ranging from 8 inches. Add the right kind of insulation. Bulky materials resist conductive and to a lesser degree convective heat flow in a building cavity. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.

She has an annual heating bill of 1 600. The higher the r value the better the thermal performance of the insulation. R value is a measure of insulation s ability to resist heat flow.