Rough-in For Exterior Door

Q: I am installing an exterior door in a family room addition. I have ordered the door, and I am preparing to build the framing around the opening. The manufacture of the door has given me the rough-in opening. But I am confused about the height. Is the height of the opening measured from the sub-floor or the floor joists?

A: Measuring the rough-in height of an exterior door is not as simple as many think. In fact one of the most common mistakes made on exterior door installation is the rough-in height.

The rough-in height is relative to the thickness of the flooring you are going to install on the interior side of the door.
My recommendation is that you place a ¾ inch piece of weatherproof plywood on top of the sub-floor and take your height measurement for the rough-in from the top of that board.

Additional information on height rough-in for an exterior door.

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