How to Assemble an Andersen 400 Series Gliding Door

Have the 2-by-4-inch pieces of lumber nearby. The longer piece needs to measure longer than the stationary door panel width. The two shorter pieces are used for bracing the longer piece. Insert the top of the stationary door panel into the frame. It fits into the wider section, known as the parting stop. The narrower section is for the screen.

Fit the bottom of the stationary panel into the sill. Slide the panel over until it seats firmly against the side door jamb. Use the lumber to brace the stationary unit in place. Put one shorter block of wood so it sits parallel to the side jamb on the sill. Place the longer piece at an angle so it pushes against the stationary panel. The other short block is placed to protect the door from the hard edge of the longer piece of wood.

Make sure the stationary panel is aligned with the scribe mark on the sill. Place the sill insert on the bottom edge of the stationary panel. Drill holes 3/8-inch deep with the 1/16-inch drill bit at the marks on the sill insert. Fasten the insert to the panel with the gray screws that came with the door unit.

Attach the head bracket to the pre-drilled holes in the head jamb, next to the stationary panel. Use the painted flat-head screws for the head bracket. Remove the lumber bracing the stationary panel. Depending on the model of door you have, you may have to slightly move the stationary panel to reach the pre-drilled holes.

Use the caulking gun to apply a bead of sealant up the vertical edge of the stationary panel. The sealant goes on the edge that faces the inside of the house. Install the weatherstrip on the sealant using the black foam plugs at the top and bottom of the panel. These foam plugs help block water from leaking inside. Fix the weatherstrip into place with painted flat-head screws.

Lay the moving door panel on a flat work surface with the exterior side of the door facing up. Lay a bead of sealant up the edge opposite the door handle holes. Put the weatherstripping on the sealant and fix the strip into place with the painted pan-head screws.

Remove the inside head stop from the door frame. There are two screws holding the head stop in place. Set them to the side until it is time to reinstall the head stop. Lift the moving door panel and set the bottom edge into place so that the rollers on the panel are on top of the sill rib. Tip the door up until it is upright and reinstall the head stop. Test the door to make sure it slides properly.