Replies

1. 
   hammer1 | Jul 26, 2009 03:49pm | #1

   Standard interior doors start at 12" and go up every 2" to 36". You frame the rough openings 2 1/2" - 2 1/4" larger than the actual door size. This allows enough space for the jambs and some shimming room. 2 1/4" is enough for modern door jambs which only add about 3/4" to each side. Old style solid jambs can be 1". You also frame the height 2 1/4" taller than actual door size which is normally 6'8" or 6'6". If you are close to a corner, make sure there will be enough room for the casing.

   Beat it to fit / Paint it to match

2. 
   GregoryPaolini | Jul 27, 2009 02:05pm | #2

   My interior doors typically end up being a 1/4" less in width than the opening. So a 30" door, ends up being 29 3/4".  That should give you a good fit and clearence for the hinges.

    If you're building the jambs and everything, then you can build it what ever size you want, taking into account the rough framing specs that were already mentioned.

   Gregory Paolini

   http://www.GregoryPaolini.com

   Custom Furniture, Cabinetry, and Woodworking Instruction

3. 
   Spalted | Jul 28, 2009 04:03am | #3

   My rule of thumb starts in my pocket. A nickel gap (about 5/64ths) seems to work for most hinges but some of the cheaper ones are really fussy- That is if you mortise the full thickness of the leaf into the jamb and the door, it may not close correctly. Same with the latch hardware. I personally make my interior doors about 3/16ths smaller than the jamb opening in each direction. It's enough to allow most hinges and hardware to function and still keep a neat reveal. It IS really tight in most instances, however, and I usually have to trim at least the top and bottom of a door anyway for old construction.

4. 
   gb93433 | Jul 28, 2009 05:35pm | #4

   The standard gap is to allow 1/16" clearance on the top and bottom and hinge side, and 1/8" on the latch side. If you bevel the hinge and latch sides 3 degrees, you can easily allow 1/16" clearance on all sides.

   When I make doors I make them at the nominal door size leaving the styles long to be cut off later. A 2'6" x 6'8" door would be made at 30" x 80" x 1-3/4" and the jamb opening would be 30-1/8" wide.

   When I make interior doors I make them at 1-3/4 think rather than planing down material to get to 1'3/8". It is easier to make them 1-3/4" than 1-3/8" and makes a better door.