Glass doors should slide easily in place

Q: I have a 20-year-old house that has sliding glass doors. These doors have been repaired so many times that I’ve lost count. I want to replace them. How difficult is this?

A: After years of bullying a pair of sliding doors, I don’t blame you for replacing them. I’m sure you’ve forgotten how easily they are actually supposed to roll. Since you are replacing existing doors, you won’t have to cut a hole in your wall, which will take most of the fear out of it.

It is crucial to order the right size doors. When you order, give the vendor the rough opening size, which is measured from the wall framing on one side to the other, as well as the height from the header to the floor. For this, you will need to remove the inside trim. Measure in several different places and use the smallest number you find.

Now also is a good time to make the changes you’ve always envisioned. You can order a right-sliding or left-sliding door (as viewed from the outside), or you can add grids to the doors for a French door look. It’s up to you.

Just make sure you get the dimensions right and wait for the arrival. By the way, many doors come in standard sizes, so you may be able to just buy them off the rack at a home center. As a benefit, the new doors should just slide right into the opening.

You will have to put together the frame for the opening, so lay the parts out on the floor and assemble it there. The instructions will be pretty clear, but generally you will screw the corners together and set the frame into the opening. Assemble the frame with the exterior side facing up. Apply silicone to each joint (it’s usually supplied with the kit) and screw each corner together. They will take five screws apiece and you should alternate sides of each corner to lock in the joint.

Once the frame is assembled, you can remove the old doors and frame from the opening.

The sliding door will have adjustment screws near the bottom of the door on either end. Turn the screw counterclockwise to lower the sliding door, then lift it out.

The stationary door will be locked into place with a bracket at the top and bottom. Remove the brackets and then the door.

You will have to remove the molding on the inside and outside of the frame. Cut the caulking with a utility knife and goose out the molding with a screwdriver. The stucco molding on the outside can be a real pain to match so try to be as gentle as possible because you will reuse this if you can. Then remove the screws that hold the frame in the opening.

Now you are ready to install the new frame. If you are installing on a wood subfloor, check the sill to make sure it is level. If not, you can add shims to help even it out.

Apply a continuous thick bead of silicone to the underside of the frame’s sill and set it into place. Place some wood shims on either side of the frame near the bottom to keep the frame from sliding around on the slippery silicone.

Then, line up the edge of the inside frame with the drywall. You can do this by holding a board against the drywall and the frame will stop when it contacts the board. This way, the interior molding will be perfectly flush with the wall and frame.

The frame will have predrilled holes to secure it to the rough opening’s framing. Before you start screwing, make sure the sides are plumb by holding a level against the jambs. Shim wherever is necessary to get the frame plumb and square, and then screw the frame into the rough opening.

You can check for square by measuring the diagonals from corner to corner. If the frame isn’t perfectly square, a few gentle taps at one of the bottom corners will fix it.

Install the weather stripping along the stationary door and move to the exterior. Slide the top of the door into the track and swing the bottom into position. Push the door all the way until it is seated against the side jamb and lock it into place using the top and bottom brackets. The sliding door installs similarly except that it is done from the inside (you first have to screw on the rollers on the bottom of the door and also the handle).

Reinstall the stucco mold and interior molding and then caulk all of the edges. When in doubt, caulk it. You will likely have a little stucco patching to do, but it will be minor. It’s worth it for another 20 years of a smooth-rolling sliding door.

Michael D. Klimek is a licensed contractor and president of Pro Handyman Corp. Questions may be sent by e-mail to: questions@pro-handyman.com. Or, mail to: P.O. Box 96761, Las Vegas, NV 89193. His Web address is: www.pro-handyman.com.