Question on hanging prehung door

[Markk]

Hello, I bought a prehung door and the frame is a half inch shorter than the old door. Can I shim the top of the door or add a half inch thick board and then put the frame in? Thanks

 

[aircommuter]

Yes, the top doesn't really hold much, some people like to shim the top, I like a solid board if the surfaces are paralell. Just don't make it tight. Make sure the bottom of the door clears your flooring material or mats or is adjusted to the threshold if you have any of those items.

 

[Daedalus]

You're supposed to shim. Put the screws right through the shims. Make sure the angles are right and the jambs flat.

 

[Markk]

Thanks, it has a threshold. Just wasn't sure if 1/2 was to much to shim.

 

[CJ7VFR]

Thanks, it has a threshold. Just wasn't sure if 1/2 was to much to shim.

No, a half inch is not too much. The two "people" doors in my garage have about a half inch of space between the door jams and the rough door opening.

I did as others have said and shimmed the doors and then put the screws right thru the shims. I did drill pilot holes thru the door jams and shims first so that the shims would not crack when I put the screws in there.

I also placed the shims where the hinges are on one side, and used 5 sets of shims on each side and several on the top. The bottom was already pretty flat and did not need any shims.

If the gap is bigger than a half inch, then maybe putting in a solid piece of wood to take up the gap would be a good idea like mentioned.

Jim