Over Rafter Roof Insulation

Insulating the roof above the rafters is known as warm roof insulation as the rafters are brought into the insulated envelope of the building.

Over rafter roof insulation.

Superfoil makes pitched roof insulation a breeze with its easy and quick installation methods with no excessive measuring or cutting required. One of the keys to over roofing is to tie the air control layer of the roof assembly to the air control layer of the wall assembly. Arguably the most popular pitched roof solution installing insulation between and under the rafters uses the depth of the structural timbers to best effect. Its versatility is the key to its popularity whether being used to achieve.

By using the continuous layer installation method it also avoids thermal bridging issues. The table below shows what levels of insulation are cost effective for different climates and locations in the home. Superfoil manufacture a wide range of products suitable for both under rafter and over rafter installation. Insulation level are specified by r value.

An efficient room in a roof in a new build property where over rafter insulation is not desirable. On the gable ends this was pretty easy. Here s how you fix it together. Insulated roof assemblies can be vented or unvented.

When it comes to pitched roofs however adding a thick layer of insulation to the rafters can result in a depth of roof construction that may not suit every site meaning over rafter insulation sarking only is not a viable option. To protect the roof from the potential of condensation occurring unseen within the construction it s important to remember that the layer of insulation installed over the rafters should as general rule be double the thickness of the insulation layer between the rafters. Staple plastic or foam baffles to the roof sheathing near the eaves to keep the material away. However most cathedral ceilings and low slope flat roofs are insulated roof assemblies.

Insulation positioned over rafters in a pitched roof is called a warm pitched roof. With this kind of roof the insulation follows the slope of the roof. For the same reason insulation shouldn t touch the roof s underside. A roof over a vented unconditioned attic does not need to include any insulation.

The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow. The weight of the tiles or slates is taken by the counter battens which are laid on top of the insulation a non structural element. This over rafter insulation method also reduces thermal bridging giving an airtight continuous layer of high performance insulation and results in a well insulated attic space.