How Deep Should Roof Insulation Be

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.

How deep should roof insulation be. Handy homeowners can install blown in insulation in the attic. What depth of roof insulation should i install. Cellulose blown in ceiling insulation is a good choice for diyers. A layer of rigid insulation board can be added either on top of the roof s weatherproof layer or directly on top of the timber roof surface with a new weatherproof layer on top of the insulation.

How deep to put blown in insulation. If you have a wall ceiling roof construction whereby you need to insulate the ceiling up to the roof membrane then you have to install rafter vents to allow air to continue to flow. Mark the desired level on different roof trusses around the attic before you start photo 4. You should leave the space under the roof tiles free from insulation to give adequate ventilation so that you don t get condensation or water coming through the tiles.

Inspecting your attic insulation. Insulation level are specified by r value. Blowing insulation into walls is best left to the pros because it involves drilling into stud spaces that may contain electrical. The higher the r value the better the thermal performance of the insulation.

The key factor that helps to understand the answer to the how deep should my attic insulation be question is getting your head round the r value of the different types of insulation. A flat roof should preferably be insulated from above. R value is a measure of insulation s ability to resist heat traveling through it. When you re blowing insulation it can get dusty and hard to see whether you ve got it deep enough around the entire attic.

The table below shows what levels of insulation are cost effective for different climates and locations in the home. We have seen this many times as free insulation is being fitted by untrained unskilled fitters. If you re scratching your head r values are the ratings used to quantify the thermal resistance insulating qualities of each material. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.

Warm loft insulation is used on pitched roofs where you are using the loft space as a room or for storage. The insulation is installed under the roof in the slope. A poorly insulated attic lets heat escape through the roof wasting energy used to warm. The recommended depth of blanket style insulation glass or mineral wool for a loft is 250 to 270 mm.