A doorknob doesn’t have the tendency to break off, and if it’s equipped with a keyed lock, it adds additional safety and convenience. How many times has each of us stood at a locked screened door shouting for all the neighbors to hear, “Open the door; I’m locked out again”? With this type of lock, all you need is the key.
You can find a nice selection of replacement locking doorknobs for aluminum storm doors at your local home center or hardware store. They are inexpensive and typically require less than an hour to install. The mounting screws may be rusted in and stuck, so penetrating oil may help free them.
The first step is to remove the old handle and take it with you when you are ready to shop for the replacement. Compare the replacement with the one you have. Try to purchase a model that has the same mounting hole pattern.
If you can’t find a match, it’s not really a big problem. You can simply drill new mounting holes in the soft aluminum, as it is not difficult. Before you reinstall your new latch, clean the area behind the handle, which is usually one of the dirtiest and most difficult to clean areas on the door.
Use the template included with the replacement doorknob to accurately cut out the mounting holes in the locations specified. Align holes in the template with the existing holes, and then tape it to the door. Drill new mounting holes where needed by drilling through the cardboard or paper template into the door.
Most aluminum screen/storm doors are hollow, so you will have to drill through one side at a time. Make sure to keep your drill level, especially when you start drilling into the other side of the door. This is important so that all the holes will be aligned. Be sure to wear safety glasses to protect your eyes and work gloves to protect your hands from sharp sheet metal edges.
Remove the template and assemble the lock according to the manufacturer’s directions. When both halves of the assembly are in alignment, the handle will turn freely and the lock system will work correctly. Then, tighten the mounting screws. Close the door and check the clearance between the inside-latching handle and the old latch bar.
Most of the time, the old latch bar can be used, but since the new lock comes with a new bar, you might as well use it. Remove the screws and replace the old one with the new one. Before you tighten the screws, open and close the door a couple of times and double-check that the latch and bar operate correctly. The mounting screws are in slots in the latch, so you can move it up and down for the best alignment.
The new doorknob will also allow you to lock the door from the inside, but your children can still open the door with a key from the outside. It’s a good idea to get a set of extra keys for all members of the family. Remember that kids are kids, so you'll need plenty of extra keys!
