After installing the insulation between the roof beams, the existing blown insulation on the roof will not help heat resistance. However, it will provide sound control between floors. Despite the common advice to install insulation under the roof, this can do much more harm than good to your home. Any good roofer will advise against roof insulation whenever possible, and will prefer attic floor insulation and attic ventilation.
Although installing roof insulation can be costly at first, it will certainly save you money in the long run. Roof insulation significantly increases the energy efficiency of a house. Not to mention, it protects your roof from damage caused by cold and ice. These damages can be exorbitant to repair, so it is advisable to shell out the initial cost of installing roof insulation.
However, roof insulation is the installation of any type of insulation on the floor closest to the roof structure. Insulating a roof is much easier, and sometimes cheaper, than a roof, so if you have to choose between one or the other, roof insulation may be the best option. Insulating the roof can also do wonders to prevent any long-term damage caused by ice accumulations, condensation, or moisture. In attic rooms finished with or without dormers, insulate (2A) between the uprights of the knee walls, (2B) between the uprights and beams of the outer walls and the ceiling (2C) and the ceilings with spaces not conditioned on the top.
Those who build or renovate their homes often wonder if roof insulation is worth it. Cathedral ceilings should allow space between the roof terrace and the roof of the house for adequate insulation and ventilation. But what options do I have if I keep reading about not putting it against the ceiling? And do I have to leave space for the ceilings if I do this? A ventilation deflector must be installed between the insulation and the roof cover to keep the ventilation channel. This can jeopardize the integrity of the roof, and your roof will no longer be covered by the warranty if the damage is due to insulation in the roof.
It is not always standard to install insulation directly on the roof slope itself, which raises the question of the need for many homeowners. Even in a house with an unconditioned basement, the basement is more connected to other living spaces than to the outside, making basement wall insulation preferable to roof insulation. A properly sealed attic or well-installed insulation on a roof are much more energy efficient. For optimal energy efficiency, your home must be properly insulated from roof to ground.
Roof insulation will also make air conditioning significantly more effective in the hot summer months.
