Hi, I'm new here. I would be grateful if anyone with more carpentry experience than I have could share any trade secrets about how to get a custom door the size you need it. Nine weeks ago, I went to Lowe's and ordered a custom-sized prehung closet door for an irregular rough opening in an old house. I ordered a "net unit width" of 21 3/4". The corresponding RO size for this unit size would be 22 1/2", but that's really irrelevant since the RO is irregular--I want a unit size of 21 3/4", no more and no less. So the door came in and I measured it before taking it out of the store, and it was too small at 20 3/4". After a few weeks they never reordered it, so I got my money back and went over to Home Depot and ordered the exact same size door with a unit width of 21 3/4". Two weeks later the door came in and it was 21" exactly. So I got my money back and reordered it again, and today it came in and it was still too small at 21 1/16". This time I got my money back, and I really don't know what to do next. I'm thinking about just drywalling over the closet and forgetting the whole thing, but I thought I'd check on here first... just kidding.

My question is, how can I get someone to make me a prehung door so that when I pull out a tape measure and measure between the outside frame edges it will be 21 3/4", no more and no less? I know I could use one of the smaller doors they sent me and shim it, but it would be a difficult job with an ugly result, as I would be shimming a space over 2" and would have to use a larger molding than all the others in the house, or do a half-baked plaster patch to fill the space. I really want the right size door. Since all three doors I ordered before came in at slightly different sizes, it doesn't seem like its the same mistake each time. If anyone has any ideas, thank you very much in advance.

 

Welcome to the forums!

What type/style of door are you wanting?

 

Unless I'm seeing something incorrectly, I think any of the doors you ordered could have been made to work. Here is why:

You said: The corresponding RO size for this unit size would be 22 1/2"

You also said the doors (I'm guessing you were measuring the slab of the door) you have gotten have measured: 20 3/4", 21", 21 1/16".

The slab is usually roughly 1/4" smaller than the opening. So if you have a 3-0 door, the slab will actually be roughly 35 3/4". The jambs add about 1 1/2" to these measurements to get the overall width of the door. Therefore, a 3-0 door is usually 37 1/2" wide, and requires a rough opening that is around 38".

Usually the rule of thumb is to subtract 2" from the rough opening width to get the measurement of the distance between the jambs when the door is open.

Using that formula, you would want to order a slab door for an opening that is 20 1/2" wide. (it would probably arrive measuring 20 1/4" and turn out to be 22" wide if taking outside measurements of the jamb.) When ordering a custom sized door, that is the measurment I would give them (20 1/2 x 80) However if it was me, I would have used any one of the doors that you had ordered.

 

Thanks for your responses, XSleeper and marksr. This is a plain, solid interior door--as plain as you can get. Unfortunately, I wasn't giving measurements for the slab. The measurements I gave were the distance between the outside edges of the door jambs, so the slab is actually even smaller than that. My RO is plumb and square on one side, but out-of-plumb, warped and crooked on the other, so the RO varies from 21 3/4" at the very bottom R corner to 23". I would have to do A LOT of shimming to make one of those doors fit--not that I couldn't do it, but it would look very ugly from inside the closet, and would require using large moldings to cover up the 2" gap (the rest of the house has 1 1/4" moldings). There has to be some way to get the door to be the right size--any ideas? Thanks.

 

If these are hollow core luan or birch doors, you can take 2' slab and cut it to fit. You have to reinsert the stile or what I usually do is to rip down a 2x to fit.

 

Since you mentioned that your rough opening is plumb and square on one side only, the biggest jamb that would fit would be your SMALLEST measurement. (21 3/4). And you would still want a little rough opening around that so as to shim and plumb the jamb up in the event an adjustment is needed.

Companies don't usually go by rough opening sizes or jamb sizes when you order doors. They want the size of the finished opening that the door will hang in. If you use 21 1/2" as a jamb measurement, you would subtract 1 1/2" to get the size of the opening the slab of the door would hang in. So you would order a door that is 20x80, or 1-8 x 6-8.

However I would highly recommend that you do WHATEVER it takes to plumb the other side of your rough opening so that it is closer to 23", and order your door accordingly. If 23" turns out to be the consistant rough opening width, subtract 2" and order a door that is 21x80 or 1-9 x 6-8.

I'm sure you may be confusing the person at the box store who is ordering the door (who may or may not know anything about doors) with too many numbers, then giving him measurements that are not standard methods for ordering doors.

 

Build your own jambs and door and make them any size you want.

 

End yours and everyone else's suffering with a machine sheet, and omit the use of net width in verbal or written communications. (Net width has a different meaning to both the slab maker and pre-hanger other than the way you're using it). By now, it should be clear that communication is the issue. Xsleepers post was uncharacteristically off target, and I reread your post due ambitious and confusing statements.

A machine sheet is a very simple drawing with text notes that depicts materials, swing, sizes, clearances, and hardware locations. A machine sheet, combine with hardware templates, are the industry standard means for ordering doors and jambs worldwide.

http://i269.photobucket.com/albums/j...boy/mockup.jpg

 

Not sure which part you considered to be "off target", but I also had to read his reply several times. At any rate, the machine sheet makes things crystal clear as far as ordering is concerned.

I think the rough opening ought to be straightened out first, though. Why lose 1 1/2" of door space due to a crooked rough opening?