rough opening for non-pre-hung door

I have a 30-inch door slab for which I will build a frame. What size should the rough opening be? I suppose the opening is not supposed to be 82.5 x 32.25 as in the case of a pre-hung door that would be shimmed into place.
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B wrote:

(Door width) + (2x frame thickness) + (1") should do it nicely. IOW, width = 32.5". ________________________

Why not? You'll need to shim the frame you make, no?
-- dadiOH _____________________________
dadiOH's dandies v3.0... ...a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at http://mysite.verizon.net/xico ____________________________
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I guessed that my home-made frame will go into the opening one piece at a time, and would start with one side piece flat against the rough opening, and therefore will not get shimmed into place. Is that not the right way to do a non-pre-hung door? -B

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I would shim it......
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B wrote:

The purpose of shimming is to make the two vertical pieces equidistant and parallel to each other, perpendicular to the wall and plumb. In the case of the top piece, it needs to be at right angles to the verticals and perpendicular to the wall.
You go nailing directly to a stud, you have a snowball's chance in hell of getting the above. YMMV.
-- dadiOH _____________________________
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It is highly unlikely that the RO framing is (will be) square and plumb enough to allow that. I have done it but only in sheds where I didn't really care.
Harry K
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