WALL FRAMING

GOAL:: To become aware of energy conscious design and construction that will save energy, cost less to operate, and have less of a negative impact on the natural environment.

OBJECTIVES:: The student will have a better understanding of exterior wall construction and will be able to suggest different types of construction with higher insulation values.

LESSON/INFORMATION:: The exterior wall constitutes a large part of the total insulated package. A 2 x 4 stud wall offers 3.5" of insulation space, and a 2 x 6 stud wall offers 5.5" of space to insulate. Not only is the depth of the wall cavity increased but the width of the cavity can increase also. The larger 2 x 6 studs can be placed two feet on center rather than the standard 16" on center. You also gain another insulation factor with a 2 x 6 stud wall. Since the studs are placed farther apart, there are fewer studs in the wall. Studs conduct more heat than the insulation since it extends through the wall cavity and has a smaller R-value. Therefore, the fewer studs in the exterior wall, the less heat is conducted through the wall.; A 2 x 6 stud wall increases the cost of construction slightly because wall finishes might have to be thicker when spacing studs at 2 feet on center or at windows and doors where extra casing is required. There is not much extra cost in studs because fewer studs are used with 2 x 6's at 2 feet on center. However, the overall savings on utility bills can pay for these extra costs.

ACTIVITY:: 1. Figure the added cost of a 2 x 6 stud wall at 24" on center over a 2 x 4 stud wall at 16" on center. Use a house with 200 feet of exterior walls with two 3' doors and twelve windows 3'x 4'. Get material cost from a local lumber yard.; 2. Figure the cost of insulation differences between the two. Get material cost from a local lumber yard.

TEACHER'S NOTES:: To see the cost differences in walls with 2 x 4 studs at 16" on center versus 2 x 6 studs at 24" on center, have students break it down into:; Cost of stud and plate material (price at local lumber yard).; Cost of labor (give students a local average wage/hr.).; Cost of insulation (price at local lumber yard).

RECOMMENDED READING:: Natural Louisiana Architecture. Cazayoux, Hebert and Winn. Baton Rouge, LA: Louisiana Department of Natural Resources, 1991.; Energy Efficient Florida Home Building. Vieira and Sheinkopf. Cape Canaveral, FL: Florida Solar Energy Center, 1988.; Low-Cost, Energy Efficient Shelter. E. Eccli. Emmaus, PA: Rodale Press, Inc., 1977.

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