A.There is almost no difference in the bearing capacity — the wall’s ability to support a compressive load, which is how most walls are loaded. Bearing capacity is a function of the footprint area of all the studs in a wall. For example, a 4-foot section of wall would have three 2x4s, but only two 2x6s. The total bearing area of three 2x4s is 15 3/4 square inches; two 2x6s have a bearing area of 16 square inches.
In bending, however, such as from a wind load, a 2x6 wall is considerably stronger.
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