Insulating your ceilings
Some do-it-yourselfers, even handy types, pale with apprehension when it comes to insulating the house.
Homeowners may picture huge machines running amok, blowing cellulose all over the wrong places, even bulging out walls.
Rest assured, that never happens, or hardly ever. And while house walls may pose a problem for do-it-yourselfers, there are other places they can insulate at a minimum of effort and cost, and a maximum of heating fuel saved: the attic floor and the basement ceiling.
THE ATTIC FLOOR...
1. Measure the distance between joists. If it is 14 1/2 inches, it means the joists are 16 inches on center (16 inches from the center of one joist to the center of its neighbor). If that is the case, buy rolls or batts of 15-inch-wide fiberglass 6 inches thick, with a paper vapor barrier. If the joists are 22 1/2 inches apart, buy the 23-inch-wide fiberglass.
2. Wear protective clothing, including a paper mask, heavy latex or light cotton gloves.
3. Lay the insulation between the joists, with the paper backing down, facing the rooms below. It will be a snug fit, and you can tuck the paper snugly against the sides of the joists and the ceiling below.
4. If there are electrical cables in the floor, they should go on top of the insulation, unless they are stapled to the sides of the joists. The big concern for cables is that, set between insulation and ceiling, heat could build up.
5. When you come to cross-bridging (wood strips connecting each set of joists in the form of an X), cut the insulation and then slit an end, with half going under the cross-bridging, and half going over it.
OK, you're done. Well, yes and no. You have indeed insulated the attic floor, but in this day and age of high-cost heating fuels, 6-inch insulation is not enough. Twelve inches, even more, is recommended.
6. If the insulation you just put in comes near the top of the joists, (give or take an inch), you can put unbacked fiberglass on top of everything, at right angles to the joists.
Better yet, use Polywrap (that is one brand), 8-inch fiberglass that is wrapped in polyethylene, which is not a vapor barrier. The poly is to protect one's hands from the fiberglass and is easier to drag across the insulation.
If there are floorboards in the attic, you can take them up and insulate, and put them back if desired. Or, have cellulose blown in, but make sure no cellulose is blown into the eaves.
7. If you discover recessed can lights in the ceiling, and they are fairly old (30 years or more), they cannot be covered with insulation, and insulation must be kept 2 inches away from them, lest they build up enough heat to cause a fire. If they are labeled "no clearance," they can be covered.
...AND IN THE BASEMENT CEILING
The basement ceiling is another place you can insulate at minimum cost and effort. Why bother insulating a basement ceiling? Doesn't warm air rise, and shouldn't the basement be warm if possible?
Warm air does indeed rise, but heat is lost through an uninsulated barrier in all directions. The heat in a basement is totally wasted.
If the joists are open, determine the space between joists and buy 6-inch fiberglass with paper backing. Use batts instead of rolls; they are easier to handle in the rather awkward job of setting them between the joists.
Just set the batts in place, with the paper backing up, toward the rooms above.
You cannot staple the batts in place, so instead place insulation hangers between joists at 24-inch intervals, under the insulation. The hangers are pointed wires of the proper length that are inserted between each joist, and form a spring that holds the insulation in place.
You can staple Tyvek (not a vapor barrier) to the bottom of the joists to keep fiberglass from wafting down on heads and other parts of the body. Do not use polyethylene plastic; that is a vapor barrier that does not belong in that position. The white Tyvek will also help reflect light in an otherwise dark basement.
