If exterior door rough opening is not disclosed, standard practice is to frame the door width oversize by how many inches?

If exterior door rough opening is not disclosed, standard practice is to frame the door width oversize by how many inches?

• A. 1 inch
• B. 1.5 inches
• C. 2 inches
• D. 2.5 inches

Answer: (C)

When the exterior door rough opening size isn’t disclosed, you frame the opening wider than the door by about two inches. That extra width gives you room to shim and plumb the jambs on both sides, adjust for square fit, and still accommodate weatherstripping, threshold, and minor variations in the door, frame, or flooring underneath. If you only left about one inch or so, there isn’t enough allowance to properly align the door or to install the jambs true and even; going to two and a half inches would create an unnecessarily large gap that would require extra trim or compromise insulation. So, two inches is the standard practice.

When the exterior door rough opening size isn’t disclosed, you frame the opening wider than the door by about two inches. That extra width gives you room to shim and plumb the jambs on both sides, adjust for square fit, and still accommodate weatherstripping, threshold, and minor variations in the door, frame, or flooring underneath. If you only left about one inch or so, there isn’t enough allowance to properly align the door or to install the jambs true and even; going to two and a half inches would create an unnecessarily large gap that would require extra trim or compromise insulation. So, two inches is the standard practice.