I'm writing regarding the discussion on back-blocking for drywall seams (Letters, 3/08). I've been asked about this code issue many times. I know that there are efforts under way to have some back-blocking products accepted in the code, and that many inspectors will accept the technique.
I recently finished a job where the ceiling of an addition had to blend into the existing ceiling. For backing, the carpenter had attached a 2x4 to the edge of the outer ceiling joist of the existing ceiling. If I had attached the new drywall to the 2x4, it would have created a seam that was difficult to hide — most likely a bump in the ceiling...
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