How to Replace an Exterior French Door Astragal

By |Last updated on |Doors|27 Comments

This project shows how to replace the exterior french door t-astragal (or simply astragal). An astragal is the moulding attached to the inactive door that contains the slide bolts, strike plate and weatherstrip to seal.

The new french door t-astragal is highlighted in this photo:

Exterior French Doors: New Aluminum Astragal

Exterior French Doors: New Aluminum Astragal

This is the interior view of the French doors and the new t-astragal:

Interior View of the New French Door Astragal

Interior View of the New French Door Astragal

This set of French Doors were in need of several repairs. So far I’ve replaced the door hinges and weatherstrip. Replacing the split and bent astragal will complete the overhaul.

Broken French Door Astragal

The bottom end of the exterior door astragal is bowed outward causing a gap in the weather stripping. The white section of stick-on weatherstripping (red arrow) was added by the prior homeowner in an attempt to seal the gap.

Exterior French Doors: Bent Astragal in Need of Repair

Exterior French Doors: Bent Astragal in Need of Repair

The problem with the original wood astragal has split around the bottom slide bolt (also called a ‘flush bolt’). The t-astragal slide bolt design is poor (as you will see in the following photos) because it was only a matter of time before the wood split due when active door closes and bumps against the astragal:

Exterior French Door Repair: Split Wood Astragal and Slide Bolt

Exterior French Door Repair: Split Wood Astragal and Slide Bolt

How to Replace an Exterior French Door Astragal

The following steps show to remove the wood astragal and install a new aluminum astragal.

The inactive French door to which the astragal is attached is removed by tapping out the hinge pins and the door is taken to the workshop. See this article for details on how to remove a door.

Astragal Repair: Remove the Inactive French Door

Astragal Repair: Remove the Inactive French Door

The exterior French door is in a pair of jigs made from scrap 2×4 blocks with the astragal side up. This is a view of the door bottom:

French Door Set in Jig for Repairs

French Door Set in Jig for Repairs

The wood astragal around the slide bolt is clearly visible in the next photo. The slide bolt fits in a U shaped mortise. Each time the door closes, the slide bolt levers sideways in the mortise as the bolt hits the threshold, causing the astragal to split. The slide bolt is made of two metal halves that are held together by the mortise, so it separates as the wood splits. A very poor design that was destined to fail in my opinion.

Exterior French Door Repair: Broken Astragal at the Bottom Slide Bolt

Exterior French Door Repair: Broken Astragal at the Bottom Slide Bolt

Here’s the bottom view of the split t-astragal. The red lines highlight how the wood astragal split and bent outward in the direction of the arrow.

Exterior French Doors: Wood Astragal and Weatherstrip

Exterior French Doors: Wood Astragal and Weatherstrip

The top of the astragal and door is shown below. The fine red line (click on the image for a full size view) delineates the astragal from the door body. This door has a metal skin whose edges are folded over a wood door frame.

Exterior French Door Repair: Top of Door and T-Astragal

Exterior French Door Repair: Top of Door and T-Astragal

This project is continued in How to Replace an Exterior French Door Astragal – Part 2.

Take care,

Bob Jackson

Copyright © 2019   Reproduction strictly prohibited.


  1. Leonard Coggins April 23, 2015 at 10:03 am - Reply

    I am interested in purchasing an exterior door T-Astragal for a Stanley french door. What do I need to do and how much does it cost including shipping?.

    Also I live near Tallahassee, Fl. and was wondering if there is any place near here that I might be able to go and buy it here.

    Leonard Coggins

    • Bob Jackson April 23, 2015 at 2:48 pm - Reply

      Measure the height and thickness of your door, note if you have a deadbolt then check with local building supply stores. If you want the Endura’s Ultimate Astragal the local distributor in Tallahassee is:

      1369 Blountstown Highway
      Tallahassee, FL
      P: 850-576-5177

  2. Marty June 21, 2015 at 4:28 pm - Reply

    My French door opens from the side, not the center of the door; so my astragal does NOT contain anything other than the door hinges. The movable door has the lock on the wall to the right. My question is can I find an astragal that is just a “post” for the opening door hinges and is attached to the stationary door?

    • Bob Jackson June 21, 2015 at 10:56 pm - Reply

      Sounds like you have a folding outswing door which looks similar to but is different than a French door. Is that correct? What problem or issue are you trying to solve with the doors? An exterior astragal is a door edge moulding and weatherstrip. It’s not designed to attach and support a door hinge.

  3. Frank July 26, 2015 at 6:20 pm - Reply

    Please tell me where to purchase astragal for metal doors. Would like the Aztec or aluminum.
    Frank Baughman

  4. dave cairel September 14, 2015 at 12:54 pm - Reply

    i live in Lombard, Il do u know of any place here i can order astragal from Endura Dist. I have a Peachtree 3 panel French door both active and passive swing into house. thanks

  5. Joe Consolini October 1, 2015 at 10:52 pm - Reply

    I have a set of aluminum French doors with the astragal seal that is falling apart after 15+ years in the sun.
    I just need to replace the rubber/vinyl seal not the whole astragal & seal.
    Where can I buy a roll of the angled “T” shaped seal which is at least 1/2″ and the “T” section that fits in the slot/channel in the astragal on the door edge?
    I’ve looked everywhere, even China! but found nothing…

    • Bob Jackson October 2, 2015 at 9:33 am - Reply

      Look along the door edges – especially the top and jamb/hinge side – for a manufacturer’s label. Call the manufacturer or local lumber / millwork supply yards to see if they can identify the astragal and order a replacement seal.

  6. LeighAnn November 30, 2015 at 1:50 pm - Reply

    On your 4th picture down from the top, named: Exterior French Door Repair: Split Wood Astragal and Slide Bolt…. you show a red arrow pointing to “extra weather stripping”.
    How do we replace that weather stripping? Or can we? It looks to me like it slides into a slot. But how in the heck can I get it out of there? Pliers? It just is really wedged in there! Any tips on how to remove and replace it? By the way, super site!!!

  7. LeighAnn November 30, 2015 at 1:55 pm - Reply

    Oops…. I may have messed up in my last question. The picture say’s “Added weatherstrip”. Ok, I assume that is a piece of weatherstripping that someone added next to the original stripping? Looks to me the original is the brown colored stripping. Same question applies though. Can that original brown stripping be replaced, and how? Sorry for the mix up!

  8. gene January 6, 2016 at 3:01 pm - Reply

    i removed the weather strippping in thr middle of the exterior french door i purchased the peace to replace it but the hard dge witch goesinthe grove wont stay with glue what do i need to get to fix it

    • Bob Jackson January 6, 2016 at 6:17 pm - Reply

      Try tapping the door jamb weatherstrip in the groove with a rubber mallet. Let me know if that works.

  9. Jonathan P. Oyen February 1, 2016 at 2:56 pm - Reply

    Using Therma-Tru’s online function for determining what specifications one needs, regarding the measurements, 5/8 and 7/8 inch, is that speaking to the gap between the doors?

    • Bob Jackson February 1, 2016 at 3:42 pm - Reply

      Not sure which “online function” you’re using. Is it the DoorWays™ App? Or point me to the design web page in question.

      You can also call Therma-Tru Customer Service at 1-800-843-7628 (1-800-THERMATRU).

      • Jonathan P. Oyen February 8, 2016 at 5:05 am - Reply

        Thank you for the reply. I just happened to see it, today.

        The area of the Therma-Tru website can be reached by using the following URL:

        It walks you through various selection options, one being where you select either 5/8 or 7/8, which can be found under the category: “What type of astragal?, Click hereto identify if you need (Left) or (Right) handed products.”

        Thus far, I have chosen the one depicted in the upper, left hand corner, being a 5/8 one, since my current, wood astragal measures 5/8 across, the piece visible in the gap between doors.

        I am especially interested in buying one from Therma-Tru because, since researching by way of Internet and, more so, by actually visiting a local door shop, I have discovered the standard width to be 1/4 inch.

        My challenge, now, is in finding a dealer who either carries it or can assist by ordering it for me. I punched in my zip code and it lists Lowe’s among local dealers. I plan on printing out the page from the Therma-Tru website and bringing it to a local Lowe’s.

        Hopefully, they can order it for me, as I don’t believe they stock them. If not, I will be relegated to get one made by MD from Amazon and, if need be, use an 1/8 inch shimmy placed behind the length of the astragal to get that additional width.

        I never realized that finding this device would be so difficult.

        Again, thank you for your reply.

  10. Jonathan P. Oyen February 9, 2016 at 3:09 am - Reply

    At the office, I called my local Lowe’s and gave them all the info on the Therma Tru astragal and was told they’d (the gentleman I spoke with) call back. Meanwhile, I called a local lumber yard and got a reply back in less than 15 minutes and had my part ordered in no time flat. Never got a call back from Lowe’s.

    After work, I stopped by Lowe’s to pick up a couple of door bottom snap on weather stripping and some shims to use in yet to be made door jigs (patterned after the ones you show on this site) to be used to place the door when taking off the existing wood astragal and replacing it with the new Therma Tru one ($65.00 plus tax) that is suppose to be arriving as early as tomorrow. Much to my pleasure, it is less expensive than the others that I had found during my research, including the MD one that can be acquired by way of I’ll also use the jigs to work the bottoms of the doors.

    I thought about asking the guy at Lowe’s door section, who was helping out a couple for what seemed to be an hour, but, since I already coordinated for an astragal elsewhere, I concluded that he wasn’t worth my time, as he didn’t think I was worth his.

    Anyway, I am happy I was able to find what I was looking for and now have procured the items I need to fix the doors. Much better than the $375.00 base estimate a local contractor gave me to do the work.

  11. Jonathan P. Oyen February 16, 2016 at 7:42 pm - Reply

    Well, I am finished. The door store ended up receiving an Endura Ultimate Astragal Lite. I was surprised, but glad to accept, nevertheless, after my saga of trying to chase one down.

    This was a good, learning project, with icing on the cake being a cost savings of about $300.00. Another way of looking at it is, by doing it, myself, I got paid $125.00 an hour (contract wages – what I was quoted by a local business) and saved $50.00 on the astragal by going through the local door store, having them order it for me.

    I also have door jigs, that I built, should I need to do some more door work in the future.

    Thanks for your advice.

  12. T. Autrey March 13, 2016 at 5:48 pm - Reply

    My French Doors are both “Active” doors. We’ve spent more money than I care to admit, trying to stop the rain/water leak which occurs where the doors meet in the middle – at the bottom. Can the metal astragal be used when neither door is inactive?

    • Bob Jackson March 14, 2016 at 7:38 pm - Reply

      > Can the metal astragal be used when neither door is inactive?
      No because an astragal for an active/passive French door has top & bottom hinge pins to lock the passive door in place.

      Do you have outswing French doors? i.e. They swing to the outdoors when opened? Do your doors have an astragal? If the doors are leaking in the middle it’s probably caused by a worn out or poor fitting weatherstrip which is simple to replace. See pages 4 (outswing door) and 6 (astragal weatherstrip) in the Anderson Wood Outswing Entry Door parts catalog for details. I’m guessing this is similar to your doors.

      You can send pictures to bob[at] – replace the [at] with the @ symbol for more specific advice.


  13. Leo Gordon June 2, 2016 at 6:47 am - Reply

    I have a center hinged inswing wooden exterior patio door with a center post that is rotten at the bottom where it attaches to the threshold. Can this post be repaired/replaced and how?

    • Bob Jackson June 2, 2016 at 8:51 am - Reply

      Look along the edge and top of the door for a manufacturer’s label. Contact the manufacturer to inquire about replacement parts. If you’re unable to identify the manufacturer take pictures and measurements then visit a door & window millwork for their advice. They may be able to identify the door and advise if the astragal or door needs to be replaced.

      If you’ve no luck with the above talk to a cabinet maker. They may be able to fabricate and splice in a new post bottom.

  14. Jon August 13, 2017 at 2:37 pm - Reply

    Do know the mfg of the astragal that was on the doors before you took it off ? That is exactly what I’m needing .

    • Bob Jackson August 13, 2017 at 5:35 pm - Reply

      The label says “PREMDOR” however exterior doors and t-astragals are standard sizes so it any compatible astragal should fit your door.

  15. Karen January 6, 2018 at 5:02 pm - Reply

    My weather stripping to my french doors needs to be replaced, both at the bottom and in-between the doors. Lowe’s does not have anything to do this. How can I find the replacement stripping and a video on how to replace it?

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