The insulation must achieve a minimum r value of 1 0 in zones 1 to 7 and a minimum r value of 2 0 in zone 8.
Roof insulation r value chart australia.
The higher the r value the greater the insulation performance.
Building code of australia bca.
Most insulation manufacturers will first list their insulation s r value for a one inch sample then they ll give you a chart demonstrating the other r values you can achieve if you install a thicker version of their product.
For a very good introductory overview article on r value see r values over at the website of.
What r value do i need.
Let s use the r value of iko s polyiso insulation enerfoil tm as an example.
R value measures how well certain building insulation materials can resist heat.
The r value is a measure of the insulation batt s resistance to heat flow also known as thermal resistance.
You should of course see the manufacturer provided technical data sheet for the r value of specific products.
It s recommended that you install foil backed insulation in your roof to an r value of r1 0 or higher.
The r value is a measure of a material s resistance to heat flow known as thermal resistance.
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.
Here is a chart and map that details this information.
Installing foil backed blanket insulation is also a great idea if you are building a flat roof or cathedral ceiling.
As discussed earlier in australia the bca has specified the r value requirements for all regions across the country.
Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.
The insulation must be water resistant and be continuous from the adjacent finished ground level to a depth of 300mm or for at least the full depth of the vertical edge of the concrete slab on ground.
When determining how much insulation you need don t guesstimate calculate.
Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value.
R value of various materials.
Insulation in zones 1 and 2 typically require an r value of 3 or 4 while properties in zones 3 to 7 will require an r value of at least 5.
By looking at insulation as a long term investment spending a couple of extra hundred dollars on the right insulation now can save you thousands over the life of your home.
Those in the freezing alpine areas of australia require insulation with at least an r value of 6.
Insulation r value chart australia.
