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Exterior prehung wood door too long. Possible to cut?

Exterior prehung wood door too long. Possible to cut?


Old 10-01-13, 06:50 PM
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Exterior prehung wood door too long. Possible to cut?

Hi guys,

I need to replace an old exterior door (which goes from a bedroom into the yard). The problem is, the opening is a bit too short: it's 81". I'm interested in a wooden prehung door, and the manufacturer says that the assembled height is 83".

This is the door I'm considering:
JELD-WEN 1-Lite Unfinished AuraLast Pine Solid Wood Entry Door with Primed White Jamb and Brickmold-THDJW185600001 at The Home Depot

The installation instructions seem to suggest that the threshold is installed separately (before) the door is installed, so I'm thinking that perhaps I can cut the door and the jambs by ~2".

I'm reasonably handy, but I wanted to get your opinion on whether you think this is doable, or a stupid idea. Do you see any issues with this?

Thanks a bunch!
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Old 10-01-13, 06:57 PM
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That door is assembled as a one piece unit, the threshold is screwed or staple in from the bottom.
Anyway to frame the opening so it will fit without having to change the door?
Old 10-01-13, 07:22 PM
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The assembled height would include the brickmold which extends the height and width of the jams.

You might take a trip to the store and measure the door frame and get the dimension.
Old 10-01-13, 08:34 PM
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Canuk is correct. Sill to top of brickmould usually measures 83" on most prehungs. You will want to find out what size rough opening is required for this new door, compared to the size of your existing rough opening, which is the height from the bottom of the header to the rough sill the door will sit on.

Some doors vary in height though, so its always wise to physically measure, as he mentioned. I am guessing it measures 82", since the RO is 82 1/2" according to the website.

Also keep in mind that sometimes your door may actually be sitting 1/2" (+ or -) below the finished floor. So if you are measuring from the finished floor, that can throw you off. Measure on the inside, then measure on the outside. Take the casing off if needed to see where the header is. You can usually make most doors fit without too much work.

I also notice this door is not "energy star" qualified. Probably because it comes with a clear glass IGU.
Old 10-01-13, 11:10 PM
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Thanks, guys! I re-measured the rough opening, taking off the outside trims, and it really is about 81". The old door is very simple, and there was no old brickmold or old threshold. (The door used to open into an unfinished garage, which I've since converted into a finished bedroom.)

Unfortunately, this particular door is not sold in-stores. I can only order it online and have it delivered to the store.

Also, the width of the exterior wall is 8" (really!). That's *not* including drywall. It's so thick partly because I had the contractor add plywood to strengthen the wall (for seismic retrofitting). Because there are so many layers of wall, I think it's going to be really tough to enlarge the opening. The base of the opening is actually the concrete foundation, so altering that is also a no-go. =(

And just for fun, I visited the store and asked if they can make a custom door that's 78" tall. Some manufacturers don't even do it, and those that do want $3000+. (Granted, the $3000 uses nicer wood, etc.) But, that's more than 10x the price of the door I'm considering.

So, if I am off by say 1-1/2", is it possible to cut the brickmold and the door, without running into any unpleasant surprises?
Old 10-02-13, 04:05 AM
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Is the current jamb ok? You might be better off just buying a slab and replacing the door only.
Whenever a wood door is used on the exterior it is important to seal all 6 sides of the door with paint or poly. That prevents the wood from sucking up any moisture that will shorten it's life.
Old 10-02-13, 04:41 AM
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You will just need to enlarge the rough opening, and make it 82 1/2". It may involve taking off the drywall inside, and adding a new header and new trimmers. Ocassionally you get lucky and a 2x4 will be laid flat underneath the header, so that 2x4 could be removed, and the trimmers replaced.

As far as the wall thickness, you might want to attach some pictures for us to look at. The door almost always should be mounted with the hinge side flush with the drywall inside. If your door is a standard thickness (4 9/16") that would mean it would be inset 3 1/2" to one side. The aluminum threshold will only be about 5 3/4" wide, so that may not be as wide as your existing door threshold.

You would NOT want to cut the brickmould or the door, IMO. The right way to do this is to enlarge the RO.

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