Inspect the existing skylight for signs of water leakage such as water stains and rot.
Skylight insulation attic.
Learn how to insulate a skylight shaft here.
Because the shaft walls separate the interior of the house from an unconditioned attic it s essential that they be well insulated.
Unsealed attics are often insulated along the attic floor with blown fiberglass or cellulose insulation.
How to insulate a finished attic.
How to insulate and air seal skylight shaft walls.
Skylight shaft walls are sometimes vertical but more typically they are sloped to create a splayed opening.
With a finished attic insulation must help keep the attic areas comfortable.
However these kits are for use with asphalt shingles.
Set aside existing attic floor insulation to expose the framing at the base of the skylight shaft to be air sealed.
Repair skylight flashing from the roof exterior and replace any damaged framing as necessary.
Skylights are now sold as kits that usually include the necessary flashing materials as well.
Materials for a skylight are fairly basic especially in the attic.
If a skylight is installed in the roof over an attic a shaft must be built to connect the skylight with the ceiling underneath.
Rigid foam is the optimal choice for an attic.
These range in price from 150 500 for a 2 x 4 ft sized skylight.
That means insulating the attic floor only not the walls and having vents in the roof.