Magnetic screen door won't close

If your magnetic screen door won't close, the magnets are almost always missing each other, not dying. The two halves have to overlap in a straight line. When the top is crooked, one side is stretched, or one half is flipped, they push apart or sit with a gap you can see through.

Start with the hang you already have. A new screen will do the same thing if it goes up the same crooked way. The usual causes, in the order we would check them:

• The center seam starts off to one side instead of in the middle of the opening.
• The top strip is higher on one end, so the magnets walk away from each other as they go down.
• The side strips are pulled so tight that the halves cannot reach.
• One half is twisted, and the magnets are facing the wrong way for part of the seam.
• Lint, pet hair, or a folded hem is sitting between the two edges.
• The screen is the wrong width, so the middle is either floppy or stretched flat.

Watch one walk-through before you peel anything. If the seam opens around you and then stops an inch short, the sides are tight or the top is crooked. If it springs open like the magnets are arguing, one half is flipped. If it closes at the header and gaps lower down, the strip is not level.

Find which miss you actually have

Stand on the outside and look at the center from top to bottom. The two edges should overlap a little, like a curtain, not meet edge to edge and not leave a dark slot. A slot means they are not touching. A hard ridge means they are overlapping too much and buckling.

Run a hand down the seam. You want a soft zip, the sound of magnets finding partners. A silent gap is a miss. A spot that clicks and then pops open is a twist: part of that edge is turned so the magnets repel.

• Gap only at the bottom: the hem is piled on the threshold, or the top is mounted too low, and the extra mesh is shoving the seam apart.
• Gap only on one side of the middle: that side's tape is too far toward the stop, and it is pulling its half away.
• Gap that changes when you touch the header: the top strip is loose or not level.
• Closes until someone walks through, then stays open: the sides are tight, and there is not enough slack for the halves to fall back together.
• Opens by itself with nobody nearby: wind under the hem, or magnets that are spaced with empty mesh between them.

Also look at the width you bought. A screen that is much wider than the opening has to be tucked, and the tuck twists the seam. A screen that is narrower gets stretched until the magnets cannot travel the last inch. Measure the clear opening, smallest width and shortest height, before you decide the screen is faulty. The worksheet is in the measuring guide.

Reset the hang so the magnets can meet

Pick a calm hour. Adhesive that you press in a breeze grabs the wrong place. You do not need a screwdriver. You need the hook-and-loop that came with the screen, clean trim, and a few minutes of pressure.

1. Peel the side strips only. Leave the top up if it is level and stuck. If the top is crooked, take that down too.
2. Wipe the center edges with a dry hand. Hair and lint are enough to hold a gap.
3. Hold the two halves together at the header and see whether they attract. If they push apart, flip one half so the faces that want each other are the faces that touch.
4. Center the seam in the doorway. The middle of the screen belongs in the middle of the opening, not over one stop.
5. Press the top strip level. Use the header as a ruler. If one corner sits lower, every magnet under it misses.
6. Attach one side with a little slack, then the other. The mesh should be smooth, not guitar-string tight.
7. Walk through once. The halves should fall together without a hand. If they stop short, loosen the tighter side and press it on again a finger's width closer to the center.
8. On wood trim, add the push pins that came in the kit at the top corners and down the sides. Pins keep a good hang from peeling. They do not fix a twisted seam.

Press the tape with your palm, or with the side of a wooden spoon. A quick pat leaves the adhesive proud of the trim, and the strip creeps the first warm afternoon. Leave the screen alone for an hour before the dog auditions.

If the hem pools on the floor, the magnets at the bottom are standing on a wrinkle. Raise the conversation to height: a 36 by 82 inch door and a 36 by 80 inch door are not the same screen. Bunching is a size problem. Stretching a too-short screen until it closes will peel the tape instead.

When a reset will not close it

Replace the screen when the seam is torn, magnets are missing along a stretch you can see, or the mesh is the wrong size for the opening you measured. A full-length magnetic seam is the layout we trust for closing, because short strips leave empty mesh where nothing pulls. AUGO fiberglass screen (Amazon, opens in a new tab) is the editor's pick for a normal 36 by 82 inch door: the listing we opened describes fiberglass mesh, magnets that run the length of the center, a full-frame hook-and-loop mount, push pins, and keep-open snaps.

If your tape says 36 by 80, do not hang the taller fiberglass screen and hope the extra hem disappears. AUGO polyester 38 × 81 screen (Amazon, opens in a new tab) is the AUGO polyester listing written for that shorter door, with the same full-length magnet story. The fiber is different. The close is the point on this page.

Hang the replacement the same way: top first, seam in the center, sides with slack. Walk through ten times on the first evening. Look at night with a lamp behind you. Pinholes of light down the middle mean the magnets are still missing, and the fix is the hang, not another order.

• Keep the threshold clear. A mat that the hem lands on will hold the bottom open.
• Tie the halves back with the snaps when you are carrying groceries. A knot in the mesh bends the seam.
• Wash dust off the trim before a re-hang. Tape stuck to dust lets the top creep, and a creeping top opens the seam again.
• If wind is the thing that opens it after a good close, tie it open on purpose during the gust and shut it after. A light curtain is a sail.