How To Replace The Astragal On An External French Door?

This project demonstrates how to replace the exterior French door t-astragal (or simply astragal), which is the moulding attached to the inactive door that contains slide bolts, strike plate, and weatherstrip to seal. The astragal is a vertical component between door panels that allows your French door system to lock out unwanted guests, seal out water and air, and keep insects outside your home.

To install an astragal on your French door, determine which is the active door or the door you usually use when you open or close your French door. The right astragal will properly seal and secure your French doors by closing the clearance gap found between congruent door panels. To do this, locate and remove the astragal snap-in trim cover, loosen slide bolt covers, remove the bolt spring, remove astragal screws and astragal, attach new astragal, fasten strike plates, and cut the trim cover to length.

The astragal should be 79 1/4″ tall and include cut outs for or already installed flush bolts. To correctly install your astragal, measure the height of your door and the space between the doors. Therma-Tru provides an easy, step-by-step tutorial explaining how to replace the astragal boots, bolt springs, and flush bolts. To cut down your astragal, begin by measuring the length of the door panel (X) and the length of the astragal (Y) on the narrow edge.