For the same reason insulation shouldn t touch the roof s underside.
Roof atic insulation.
However most older attics are under insulated so it s a good idea to raise the r value where possible.
Insulation roofing there are various factors that affect how often a home s attic insulation should be replaced.
A finished attic should be insulated much like the rest of the house with insulation in the walls and ceiling.
Blanket insulation is available as batts or rolls and is the easiest diy insulation material.
It s available in fiberglass mineral wool plastic fibers and natural fibers.
Technically known as spray polyurethane foam or spf spray foam is most commonly applied in the space between attic rafters.
A good rule of thumb is that standard insulation should be inspected to see if it needs to be replaced at least every fifteen years.
Additionally insulation serves as a way to enhance sound proofing on the uppermost envelop of your house.
It can act as an air and moisture barrier in addition to providing very high r value.
The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow.
Insulation goes between roof and interior space if your attic is already finished it probably is at least partially insulated.
Better materials for attic roof insulation are rigid foam boards and spray foam insulation.
Staple plastic or foam baffles to the roof sheathing near the eaves to keep the material away.