# Exterior door install in concrete foundation



## Bcoleman6 (Jan 17, 2008)

I am finishing the basement and one of the last things I have to do before drywall is replacing the exterior door in the walkout basement. The foundation is 8” thick concrete once the interior wall framing is added it will be 12” thick. The hole in the foundation is also 2” off of the basement floor. Once I frame the hole the rough opening will be 78” X 34”, so I know I will need to order a custom door.
A couple of people have recommend installing the door on the outside side of the house and have it open outside, because I would have an issue finding exterior jam/threshold extensions that would fit if I installed it normally. This doesn’t seem correct to me. My thought is use a 2X12 pressure treated to make the frame, that way it will join to the wall frame and then install a prehung door opening into the house. I would then either buy extorior jam extensions, if they make them that big, or build my own. I would also have to build up some wood under the thershold to make the door level with the hole in the foundation. Am I missing something?


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## joecaption (Nov 30, 2011)

Got a picture?


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## Bcoleman6 (Jan 17, 2008)

Sure. You can see the old door is still there and I haven't framed the wall around the door yet because I not sure about install method yet.


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## ktkelly (Apr 7, 2007)

My beach house has 2x6 framing, so the "normal" pre-hung doors don't really fill the bill.

I made my own jamb extensions using some 1x stock cut to fit. Simple enough...


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## joecaption (Nov 30, 2011)

If your going to special order a door then also order it with the jamb size you need.


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## funfool (Oct 5, 2012)

You will build your own jamb extensions, it is common practice, but nobody sells them because each is made individually to fit each application.
A jamb extension is not bought, it is made.

About the threshold. I strongly recommend using a concrete product instead of any wood.
Looks like you have possibility for standing water at the threshold on exterior.
I would actually make some forms at desired hight and width, they sell high strength fast setting concrete at the big box stores, comes in a small 3# bucket and just add water and mix ... pour it in and let it dry, install your threshold on that instead of wood.


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## Gary in WA (Mar 11, 2009)

Use waterproof membrane flashing at p.t./concrete joint, not to rot the door jambs; http://www.greenbuildingadvisor.com...ressure-treated-sill-plates-and-building-code

Gary


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## cleveman (Dec 17, 2011)

I don't think you need any jamb extensions. Just install a pressure treated "door jack" to mount your door to. This can be built from 2x6's ripped down to 2x4 (same as a 3 1/2 with 1/2 sheathing on the outside. After 1/2 wall finish on the inside, this will be the proper thickness for your standard door jamb.

Ensure that your brick moulding will fit in the opening. You can rip some off the sides of it if necessary, but not much.

The remainder of the ext. wall will simply be concrete. You don't need to extend the jamb out all the way to the ext. edge of the wall in this application anymore than you would have to were the wall 3' thick.

If you could somehow get some additional height by going up or down, that would get you to a standard sized door.


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## rebelranger (Aug 1, 2012)

I would consider moving the top 2x4 to get an 80" door. Or cut an 80" door down before going custom.


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