Home » House Exterior » Doors » How to Replace an Exterior French Door Astragal – Part 3

How to Replace an Exterior French Door Astragal – Part 3

Bob Jackson
Last Updated on
by Bob Jackson

How to Replace an Exterior French Door Astragal: Mark and drill mounting holes, install the new aluminum astragal (t-astragal) and rehang the door. This project is continued from How to Replace an Exterior French Door Astragal – Part 2.

After removing the old wooden astragal and glue the split door frame, I’m now ready to install the new Triple Seal™ aluminum astragal on the patio French door. The installation instructions are a single page and the job was straightforward. The new t-astragal is 1-3/4 inches wide (to fit a 1-3/4 inch thick door) and 79-1/4 inches tall.

Exterior Door Astragal Installation Instructions
Exterior Door Astragal Installation Instructions

Exterior French Door Repair: Install the T-Astragal

The new aluminum t-astragal has very tight tolerances and fits very snugly over the edge of the 1-3/4″ wide door. Begin by aligning the astragal evenly with the top of door and use a flat hand to press the astragal onto the door edge, working evening from top to bottom along the length of the door. It’s a very tight fit – but take it slow and it’ll go on.

This view from the top of the door clearly shows how the astragal “clamps” itself over the door edge. The red line traces the door profile to more clearly show the fit between the astragal and the door. Click on the image for a full size view.

French Door Repair: Aluminum Astragal set on the Door Edge
French Door Repair: Aluminum Astragal set on the Door Edge

A wide carpenter’s level is used to verify the astragal is even with the top of the door.

Exterior French Door Repair: Check the T-Astragal Alignment
Exterior French Door Repair: Check the T-Astragal Alignment

The t-astragal screw positions are marked on the door to drill pilot holes in the wood door edge:

Mark the Screw Positions to attach the T-Astragal
Mark the Screw Positions to attach the T-Astragal

The instructions say to remove the astragal before drilling pilot holes for the attachment screws. Since the t-astragal has clamped itself tightly to the door, I chose to leave it on and drill the 1/8 inch pilot holes with it in place, being careful not to let the drill chuck make contact with and mar the aluminum astragal.

Exterior French Door Repair: Drill Pilot Holes for the Astragal Mounting Screws
Exterior French Door Repair: Drill Pilot Holes for the Astragal Mounting Screws

The astragal is attaches to the door with the supplied screws. Don’t over torque the screws or you’ll strip the threads out of the wood.

Exterior French Door Repair: Install the new T-Astragal
Exterior French Door Repair: Install the new T-Astragal

Two vinyl snap-in covers are provided with the astragal to cover the channel between the slide bolts and strike plates for the door lock. The dead bolt and strike plates are adjustable to match your door handle. I used the old astragal to align the two plates, then marked and cut the vinyl covers with a hack saw to fit.

Aluminum Astragal and Vinyl Snap-In Covers
Aluminum Astragal and Vinyl Snap-In Covers

Full length view of the patio French door with the aluminum astragal. This really cleaned up the door’s appearance!

Patio French Door Repair: New Aluminum Astragal Installed
Patio French Door Repair: New Aluminum Astragal Installed

Rehang the Exterior French Door

To rehang the door on the hinges, retract the slide bolts on the astragal, align hinge leaves on the door and jamb, then slide in the door hinge pins. This French door weighs 65 lbs and a helper is needed to hold the door.

Exterior French Door: New Aluminum T-Astragal

The new French Door astragal fits perfectly! I really liked the sturdy aluminum construction and the steel rods for the slide bolts. The rods extend up to ~3 inches beyond the door top and bottom edges to securely fasten the door in the sill and top jamb.

Exterior French Door Repair: Bottom View of the New T-Astragal
Exterior French Door Repair: Bottom View of the New T-Astragal

The new French door t-astragal seals evenly between the two doors to keep out drafts, rain, dust, etc:

Exterior French Door Repair: New T-Astragal Weatherseal
Exterior French Door Repair: New T-Astragal Weatherseal

Full view of the doors and new astragal.

Exterior French Door Repair: New Aluminum Astragal
Exterior French Door Repair: New Aluminum Astragal

My next job is to clean and paint the doors.

Hope this helps,

Bob Jackson

aluminum astragalbroken astragaldoor t-astragalexterior door astragalexterior French door t-astragal
Bob Jackson
Bob Jackson
Technology product manager by day and a prolific handyman in the evenings and over the weekends. Bob was the founder of the original Handyman How To website and that tradition continues on this site with excellent new handyman content into the future.
1 Comment
  1. Where can the astragal you used be purchased and what would be a brand name? I am updating an old aluminum clad French door that needs new flush bolts and astragal. The original astragal was replaced with an incorrect product. I am in the Desert SW and do not mind ordering what I need.
    Your three part discussion and photos gave me an understanding of the project.

Leave a Reply

Your email address will not be published. Required fields are marked *