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Slab Doors

user-2024378's picture

I'm curious if anybody can tell me why replacement slab doors are sized the way they are. Recently I decided to replace our older hollow core interior doors with solid core doors. Measured the doors, looked at the options and I figured 23 3/4 x 79 3/4 was the 24x80 that was available. When the doors came in, I found that in certain cases, I needed that quarter inch especially in the width, although in one case, I needed to trim both width and height to make the door fit. 

My goal was not to replace the entire door frame, but just the slab doors. Fortunately I was able to run the doors through my cabinet saw and trim the width, and then in a few cases, I used my router to trim the top and bottom equal amounts. 

But I still can't figure out why replacement doors are sized differently than what you get when you buy a prehung door. Anybody know? 

Box store v. custom door$ (post #215819, reply #1 of 5)

I think I know :)  When you want true dimensions you don't order from a box store. Here I go to my local lumber yard, folks who understand custom work, and they order from a company that specializes in producing authentic, "Olde Tyme" doors...and you pay accordingly. I've ordered many such doors...and now I make them myself!  It is not hard....if you have the right tools.  Come to think of it, I did once order through Menards (box store) and the door widths were only 1/8" less than the true size. What's more, they did not come with a bevel edge on the lock side...great!

Where the door appears a tad small, consider installing a thicker door stop.

Mel Fros

Thank you (post #215819, reply #2 of 5)

Thank you for sharing... I was thinking of mine too... This one helped me... Thanks...

Tools for Slab Doors (post #215819, reply #3 of 5)

Thanks for the information you gave about slab doors.  I think the doors which we get customized comes more expensive. You told us that you are making them by yourself, so can I ask a favor from you? Please tell me list of tools that are most necessary for this purpose. 

Most everything I write is SPAM

They come that way so they (post #215819, reply #4 of 5)

They come that way so they can be trimmed to size. Pre-hung doors are a fairly new technology. Older homes built in the 50's and 60's will have doors that were hung by the carpenters who built the house and will be all different sizes. Having a true dimension door makes it fit any any of those old frames. 

One of the largest part of our business is replacing old doors. I measure the height and width, measure down from the top of the door to the top of each hinge, measure to the center of the lockset, note the swing and pick them up, ready to hang ina couple of days. 

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

True to size (post #215819, reply #5 of 5)

Where I am, any single doors I buy (not prehung), are sized as described.... a 24 x 80 door is 24 x 80. Within a 1/16 or so. Slab, six panel, all the same. The only thing that varies is whether they are squar edged or beveled. Everything stocked in the yards here is square edged, but I recently had to order a couple of mahongany 30" slabs. They came in beveled on both edges; . The guy at the contractors desk never asked what I wanted, and I assumed they would be square edged. My doors were tacked on to an order for another company, and when i went to collect them the yard had to dig mine out of a pile of theirs, so it's possible they ordered a pair the same size with beveled edges and I got theirs instead of mine. I'll never know. These two were for bypass doors, so square edged would have been fine. These were the first factory bevelled doors I've seen.