Insulating a loft roof will decrease draftiness and increase energy efficiency. With a few basic tools, nearly anyone can insulate a loft’s roof in a few hours. Several options in insulation exist, from the traditional fiberglass batt to solid foam. The kind of insulation you choose may depend on whether you plan to leave the insulation exposed, or cover it with drywall or other wall material. The familiar pink fiberglass can be used to insulate a space. Always follow your local building codes and safety practices.
Use caution when using the utility knife, because deep cuts can happen quickly.Fiberglass insulation irritates the skin and respiratory tract. Wear long clothing and gloves to cover as much of your body as possible.
Don protective eyewear and a filter mask. Open and unroll just one package of insulation at a time. Allow it to rest and expand for a few minutes while you lay out the tools you'll need. Allow the other rolls to rest and expand while you are working with the previous roll. Spread the drop cloth in the area where you'll begin, and set up the ladder or scaffolding on top of it, so that you can reach the highest point of the ceiling. Most people find it best to begin in a corner and proceed around the room to the right.
Install drywall sheeting, paneling or other material over the insulation. This will keep the insulation from being exposed and make for a more finished look. Some loft dwellers may prefer to staple fabric to the joists to cover the insulation, instead of installing a ceiling material such as drywall. Applying a tightly woven and opaque fabric certainly can be quicker and less costly than having drywall installed, but local building codes and what you want the finished loft to look like will determine which choice you make.