Feedback on Double Stud Walls
I’m considering using a double stud wall for a new home. in all the literature both the inside and outside stud spacing’s are insulated and often the walls are connected at each floor with the outside wall being the load bearing wall.
I’m considering designing the building such that the inside 2X4 wall is load bearing and un-insulated. The vapour barrier would be installed on the exterior of this wall and a second wall would be built hanging from the rafters so to speak with no connection to the interior wall except at window and door openings. The space can be filled with blown in Cellulose insulation and because the vapour barrier is on the exterior it of the inside wall it should be relatively continuous.
I have a number of concerns with this approach and that’s were my questions start. First if the relative cost of moving the second wall out 4″ is minimal (space is not a factor) what benefit would I gain from insulating the interior wall? (it would entail a second round of insulating and be relativity labour intensive). Second, what are the consequences for the shear capacities of both the interior and exterior walls as only the exterior wall is covered in plywood sheathing? Third, how high can I build a curtain wall without running into problems with buckling (assuming 2X4 lumber). Finally, Fourth, will I incur problems at the openings (Window and Doors) from the walls moving independently.
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