DIYbanter - door opening

On Dec 4, 2:32 pm, car crash wrote:
I'm framing for an interior door in my basement. I was told that if
the door is 36 inches wide to frame 2 inches bigger. That is frame
38 inches which leaves 1 inch on either side. Is that correct ? I
guess there needs to be room for the shimming and the door jamb
right ?
Thanks.

Let's make sure we are talking about the same measurements here - you
can never tell for sure in one of these posts.

Assuming a 36" pre-hung door where the door is 36" and the jamb is
~3/4" on both sides - total ~37.5" - then 38" is correct, giving you
about 1/2" for squaring and shims. Try and place the shims behind the
hinges for support and remove at least one short screw from each hinge
and replace it with a screw long enough to reach into the 2x framing
of the RO.

Them RO height should typically be 2" taller than the door itself ,
but you should make sure you are aware of any issues with the floor
being uneven (especially in a basement) and, of course, the type of
finish floor you will be using. My basement floor is so uneven that I
have a bottom gap of over 1" when the bathroom door is closed but
barely a whisker of a gap above the rug with the door fully open. You
can plan for this before installation or plane the bottom of the door
later.

One last point - make sure you seal all 6 sides of the door. If there
is any moisture in your basement, the door may warp and be hard to
open and close.