How Much Insulation Do I Need In My Roof

Use our free insulation calculators to find out how much insulation material you need.

How much insulation do i need in my roof.

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. The hot roof design allows more insulation to be installed in the roof cavity as the need for a vent space is eliminated. Floors don t need as much insulation as attics. All you need to do is input the size of your loft or roof space.

Also your building codes may dictate how many and which kind of vents you need to use. They can explain local codes and how many vents they intend to install on your roof. 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. These minimum insulation levels are higher if your roof has an upper surface absorbance value of more than 0 4.

A total value of r 13 is recommended in southern climates and r 30 is recommended in northern ones. So fitting insulation in your loft attic or roof space is a great way to improve your home s cosiness factor. For example cathedral ceilings built with 2x12 rafters have space for standard 10 inch batts r 30 and ventilation. 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.

If you want to use your loft as a heated room then you need to take a slightly different approach and create a proper room in the roof. Inspecting your attic insulation. Where to install insulation. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.

And there s even more good news. Install insulation under the roofing material to reduce radiant heat gain. 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. For a warm loft you install insulation directly under the roof in the plane of the roof s pitch slope.

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. We do not recommend that you do this.