Thermal and Moisture Protection 179Insulation placed between the framing members may
be pumped in or laid in rolls or in sheets, while loose
insulation is sometimes placed in the ceiling. Roll insula-
tion is available in widths of 11, 15, 19, and 23 inches to fit
snugly between the spacing of the framing materials.
Sheets of the same widths and shorter lengths are also
available. Rolls and sheets are available unfaced, faced on
one side, faced on both sides, and foil faced. The insulat-
ing materials may be of glass fiber or mineral fiber. Nail-
ing flanges, which project about 2 inches on each side, lap
over the framing members and allow easy nailing or sta-
pling. To determine the number of linear feet required,
the square footage of the wall area to be insulated is easily
determined by multiplying the distance around the exte-
rior of the building by the height to which the insulation
must be carried (often the gable ends of a building may
not be insulated). Add any insulation required on interior
walls for the gross area. This gross area should be divided
by the factor given in Figure 14.7. If the studs are spaced
16 inches on center, the 15-inch-wide insulation plus the
width of the stud equals 16 inches, so a batt 1 foot long
will cover an area of 1.33 sf.
Ceiling insulation may be placed in the joists or in the
rafters. The area to be covered should be calculated; and if
the insulation is placed in the joists, the length of the
building is multiplied by the width. For rafters (gabled
roofs), the methods shown in Chapter 14 (for pitched
roofs) should be used: the length of the building times the
rafter length from the ridge to plate times two (for both
sides). Divide the area to be covered by the factor given
in Figure 14.7 to calculate the linear footage of a given
width roll.
Ceiling insulation may also be poured between the
joists; a material such as vermiculite is most commonly used.
Such materials are available in bags and may be leveled easily
to any desired thickness. The cubic feet of material required
must be calculated. Loose mineral or fiberglass may also be
“blown in” between the ceiling joists. Because this material
compresses easily, it is typically not done until all construc-
tion foot traffic is completed.
Insulation board that is nailed to the sheathing or fram-
ing is estimated by the square foot. Sheets in various thick-
nesses and sizes are available in wood, mineral, and cane
fibers. The area to be covered must be calculated, and the
number of sheets must be determined.
For all insulation, add 5 percent waste when net areas
are used. Net areas will give the most accurate takeoff.
Check the contract documents to determine the type of
insulation, thickness or R-value required, and any required
methods of fastening. When compiling the quantities, esti-
mators keep each different thickness or type of insulation
separate.FIGURE 14.7.Insulation Requirements.EXAMPLE 14-2 RESIDENTIAL BUILDING INSULATION
Determine the insulation required for the residential building
introduced in Chapter 13 and shown in Figure 14.8.
Floor: 5^1 ⁄ 2 -thick R 19 roll insulationCeiling: 7^1 ⁄ 2 R 22 roll insulationsf of ceiling1,200 sfsf of ceilingsf of floorUse 16 rolls16 rollsRolls of insulation1,200 sf of floor>75 sf of coverage per rollEffective coverage per roll 16 – 56 ¿1.33¿ 56 ¿75 sf1 roll 15 – 56 ¿sf of floor 50 ¿ 24 ¿1,200 sfWalls: 3^1 / 2 R 11 roll insulationUse 16 rolls15.1 rollsRolls of insulation1,135 sf of wall>75 sf of coverage per rollEffective coverage per roll 16 – 56 ¿1.33¿ 56 ¿75 sf1 roll 15 – 56 ¿sf of wall 7 ¿ 8 – high148 lf of exterior walls1,135 sfUse 28 rolls27.9 rollsRolls of insulation1,200 sf of ceiling>43 sf of coverage per rollEffective coverage per roll 16 – 32 ¿1 .33¿ 32 ¿43 sf1 roll 15 – 32 ¿