Sliding screen door repair - Shortening your door

There are sliding screen door repair situations such as when you need to shorten a frame. When patio frames sag or get distorted because of settling over time, trimming the screen door a little shorter is sometimes the quickest way to get it sliding again.

Or, you might find a used screen that is taller than what you need and have to cut it down so fits your door.

A sliding screen door repair task like cutting a door to height is not usually a big deal with the majority of screens that have mitered frames that fit together at 45 degrees.

You have to remove the screen cloth, and take the frame apart. Then trim the long bars to the desired length. (Use my tips on the measuring page)

Once the miter cut is done you will probably have to re-drill the roller adjustment hole as well. Because now that the frame is shorter the old hole may be too low or completely cut off.

A sliding screen door repair like cutting a frame to a new width is a bit more difficult because you not only have to miter cut but also make a new rectangular mortise for the roller.

As well, if you shorten the old rails the old mortise may interfere with the new miter cut and make the frame unusable when you try to reassemble the corners back in.

If you are just cutting no more than 1/4” off the width, you can get away with widening out the existing mortise by levering out new material with pliers.

That will insure the roller assembly will fit after. Any more than 1/4” will move the old mortise closer and closer to the end making the frame weaker after reassembly.

The width dimension is less critical anyway. So long as your door is more or less the same width as the glass door that slides in your patio door, your sliding screen door repair will work fine.

Avoid trying to make a 48” wide door into a 36” door wide !

To cut a new mortise properly, you are going to need a router with an aluminum cutting blade, a router table and a jig to hold the rail steady so you get an accurate cut. Once you get those things you might as well make screen doors for a living.

Cutting a screen door frame to length does not require complicated tools. Frames can be cut using just a hacksaw with a metal cutting blade.

What is important is that the frame has be clamped down and you use a miter box so that you get a really nice accurate miter cut.

Most frames are mitered together and held together by a friction fit corner. Any small defect in cutting the miter will stand out like a sore thumb when you put the frame back together.

Clamping the rail down is important because if you dont the saw will move the rail around while cutting. No matter how much you try, you wont be able to hold it steady enough.

Clamp the rail down first so that all you have to concentrate on is the cutting. A cheap wooden or plastic miter box is good enough to guide the hacksaw to cut a nice miter once everything is clamped down.

If you want to use your power miter box you will need a “non ferrous metal” cutting blade. If you try to use your standard cross cut blade on aluminum the material is so soft it will jam the blade and wreck the part you are working on.

Even non ferrous cutting blades need frequent sharpening and the use of hard wax cutting lubricant to produce consistent quality cuts.

Non ferrous cutting blades generally have more teeth than a regular cross cut blade. The teeth are also cut at a “negative rake” angle to clear the chips or aluminum cuttings.

Safety glasses and eye protection are absolutely essential when cutting aluminum with a power miter box. I have had aluminum shards fired into my face more times than I can count.

Dont take any chances. Cutting metal of any kind is much more hazardous using power tools.