## How is R-value calculated in Australia?

In general, the R-Value of a material is determined by dividing the thickness of the material (in metres) by the thermal conductivity (in W/m.K). The Total R-Value of the construction is the sum of the thermal resistance of each layer, surface air film resistance, and any bridged layers.

### How is R-value calculated?

It is simply the thickness of the insulation in inches divided by the thermal conductivity of the insulation. For example, a two inch thick sheet of insulation with a thermal conductivity of 0.25 Btu•in/h•ft2•°F has an R-value equal to 2 divided by 0.25 or 8.0.

How do you calculate roof insulation R-value?

To calculate the R-value, you simply add together the total thickness (in inches) of each insulating material within your roofing system: “For each different material, multiply the thickness by the standard R-value per inch for that material.

What is the R-value for concrete roof?

R-value Listing of Common Products

Material Thickness R-Value m2K/W
Concrete 100mm .07
Granite 25mm .009
Sandstone .014
Glass 6mm .006

## What is the highest R-value insulation Australia?

R2.7
Insulation R-Values A typical Australian home has 70mm or 90mm wall studs. The highest rated residential product to fit a 90mm spacing is an R2. 7 wall batt. Common R-values for walls include R2.

### What R-value should I install?

For optimal energy efficiency, you should also consider insulating the internal walls, floors and between floors of multi-storey homes. The ideal R-Value for underfloor insulation depends on the climate of your location and the design of your home. Typically we recommend a minimum of R2. 0 and an upgrade to R2.

How do I calculate how much insulation I need?

To determine the amount of insulation needed, start by measuring the height and length of each of your room walls. Multiply the wall’s length by the wall’s height and don’t forget to write down the spacing of the studs so you can then determine what type of the insulation will be purchased.

What is the R-value of 4 inches of insulation?

For areas with 3-4 inches of existing insulation, you will need an R-value of 38-49. For insulating flooring, you will need an R-value of 25-30.

## What R-value do I need for exterior walls?

R-13 to R-23
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. See the Department of Energy’s (DOE) ranges for recommended levels of insulation below.

### Do bricks have a high R-value?

Even though brick doesn’t have a high R-value it still helps to keep the interior temperature steady because of its thermal mass and the moisture absorbed inside the brick. Bricks absorb and store heat much better than other siding materials and then release that heat slowly throughout the day.

Is a higher R-value insulation always better?

The R value is, in essence, the measurement of an insulation sheet’s ability to resist heat flow. Basically, R values range from 1.5 to 7, and the higher the number is, the more effective the insulation sheet is at increasing thermal efficiency, and thereby, insulating your home.

What R-value insulation do I need Sydney?

What R-Value Should I Install?

Location Minimum R-Value for Ceilings Minimum R-Value for Walls
Perth, Brisbane, Northern NSW R4.0 R2.0
Sydney, Adelaide, Melbourne R5.0 or R6.0 R2.5