Uploaded June 2018 | Updated September 2026, 1 hour ago

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Building an addition using double wall construction creates super thick walls. In order to contain the dense pack cellulose insulation inside the wall cavity a buck is made in the window and door opening. I made mine out of 1/2 and 7/16" osb sheathing. Some people even go up to 3/4" and plywood as well.