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 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.

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

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

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.

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.

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.

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

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.

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

Full view of the doors and new astragal.

My next job is to clean and paint the doors.
Hope this helps,
Bob Jackson