Insulating Attic Skylights
If you are doing a major home renovation project now may be a great time to tackle this project too.
Insulating attic skylights. If a skylight shaft contains an air permeable insulation such as cellulose or fiberglass the insulation should be enclosed on the attic side to create an air barrier. To enclose and protect any insulation on the exterior of a skylight tube you could build a box out of rigid foam. If a skylight is installed in the roof over an attic a shaft must be built to connect the skylight with the ceiling underneath. The practices used to install insulation on a skylight will depend on the type of insulation that is being used.
Insulation radiant and vapor barriers insulating old skylights i have five skylights that are insulated so poorly that they provide cold downdrafts whenever the outside temperature dips below 45. Skylights are already insulated when manufactured. Seal the corners of the box with housewrap tape or for a slicker and more tubular solution you could buy a large diameter sonotube cut it in half lengthways and assemble the sonotube around the insulated skylight tube. Adding insulation to the attic is generally a moderately difficult do it yourself diy project but the benefits can be substantial.
Of all the various types of insulation used in houses fiberglass batts perform the worst. Skylight insulation in the attic probably wasn t installed correctly the first time duration. No attic it should have been insulated when installed. If you have or plan to install a skylight in your home get the insulation details right to avoid problems with comfort and condensation.
The skylight tunnel can be insulated from the attic. There are many types to choose from including blown in cellulose batt such as fiberglass mineral wool or cotton. Ther really is no way to insulate a skylight unless you cover it up. Install headers across the ceiling opening as you did for the roof opening using a single header at each end if no.
Rigid foam is the optimal choice for an attic side air barrier. House designs that use. Rigid foam is the best choice.