As with any type of insulation you need to make sure that the roof is dry and in good condition before any insulation is added.
How much insulation do i need in my roof.
First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.
These minimum insulation levels are higher if your roof has an upper surface absorbance value of more than 0 4.
Roofs and ceilings work in conjunction when it comes to insulation.
They can explain local codes and how many vents they intend to install on your roof.
The hot roof design allows more insulation to be installed in the roof cavity as the need for a vent space is eliminated.
So fitting insulation in your loft attic or roof space is a great way to improve your home s cosiness factor.
Also your building codes may dictate how many and which kind of vents you need to use.
If you do have existing roof insulation the first thing to do is to check the depth if there is only 25mm of insulating material then this is likely to date back to the 1970s as this type of.
If you can t install cold loft insulation because for example you re using your loft as a living space you will need to consider warm loft insulation.
A total value of r 13 is recommended in southern climates and r 30 is recommended in northern ones.
And there s even more good news.
It lasts for more than 40 years and should pay for itself many times over in energy bill savings as the cost of loft insulation is comparatively low.
All you need to do is input the size of your loft or roof space.
Use our free insulation calculators to find out how much insulation material you need.
Install insulation under the roofing material to reduce radiant heat gain.
We do not recommend that you do this.
If you re concerned about your building s insulation the best thing to do is talk to your roofer.
Unvented hot roof design cathedral ceilings are also an option.
You can usually get this by gluing or fastening rigid foam sheets to the joists underneath the floor and filling gaps with spray foam from a can.
For example cathedral ceilings built with 2x12 rafters have space for standard 10 inch batts r 30 and ventilation.
Floors don t need as much insulation as attics.
Inspecting your attic insulation.
For a warm loft you install insulation directly under the roof in the plane of the roof s pitch slope.