Measure the opening
Height and width of the clear area you see through, in millimetres. Take each in three places and keep the smallest.
MagicSeal · Measure and fit guide
Standard DIYWork in millimetresRead before ordering
Measure it right. Fit it once.
Most windows take three steps: measure the opening, check the frame around it, add 26 mm. The rest of this guide covers the windows that need more, including a window behind a ranch slider.
The short version
Most windows: three steps
Check the frame
Each side needs 14 mm or more of flat frame for the magnetic tape to stick to.
Add 26 mm
Add 26 mm to the height and 26 mm to the width. That is the size you order.
Step 01
Measure the opening
A magnetic screen is a little bigger than the window opening. It overlaps the flat frame around the opening and holds there on magnetic tape. So you measure the opening, then add the overlap.
- AOpening width. The clear area you see through, from the inside edge of the frame to the inside edge.
- BOpening height. Measured the same way.
- CFlat face. The flat strip of frame around the opening. The magnetic tape sticks here. You need 14 mm or more.
- DThe screen. It is 13 mm bigger than the opening on every side. This is the size you order.
- Measure the height of the opening at the left, the middle and the right. Write down the smallest.
- Measure the width at the top, the middle and the bottom. Write down the smallest.
- Check the flat face on all four sides. Each needs 14 mm or more. Do not assume they match.
- Look for anything in the way: latches, handles, window stays, or a sliding door that passes in front.
All four sides have 14 mm or more of flat face
Size to order = opening + 26 mm each way
That is 13 mm of overlap on each side. An opening 1,200 mm high and 900 mm wide needs a screen 1,226 × 926 mm.
Size helper
Work out the size to order
Enter your smallest height and width. If every side has 14 mm or more of flat face, that is all you need. Change a side only if it is narrow or has no flat face.
If your three readings differ by more than a few millimetres, the opening is out of square. Send us the readings and a straight-on photo before you order.
You will see the opening called the daylight opening on some of our pages. It is the same thing.
Step 02
If a side is narrow or has no flat face
Work out each side on its own. A side that is fine still gets its 13 mm.
A narrow face, under 14 mm
Narrow face - less than 14 mm on that side
Add the face width, less 1 mm
An opening 500 mm wide with 12 mm of flat face on both sides gets 11 mm a side: 522 mm wide. If only one side were narrow, the other would still get 13 mm: 524 mm.
Under 10 mm of face? Ask first
The tape needs at least 9 mm stuck to the frame to hold. If a side has less than 10 mm of flat face, send us a photo before ordering. A little tape overlapping the glass can be fine; too little on the frame is not.
No flat face at all: use a plastic angle
Some windows have a side with nothing flat to stick the tape to. It is usually where the window runs straight into a wall or into the frame of a sliding door. A 15 mm plastic angle goes on that side first, and gives the tape a face.
- AThe width to measure. From the surface the angle sticks to, across to the inside edge of the flat face on the other side.
- BPlastic angle. Goes on first and gives the tape a flat face.
- CThe wall or door frame the window runs into. No flat face on this side.
- DA normal flat face.
For this window the width to order is A, take off 2 mm for the angle side, add 13 mm for the flat-face side.
A side with a plastic angle
Measure to the surface the angle sticks to, then take off 2 mm
Do not add 13 mm on an angle side. The angle sits about 2 mm into the opening, so the screen is 2 mm smaller on that side.
One angle side: from the wall on the left to the inside edge of the flat face on the right is 900 mm. Take off 2 mm for the angle side and add 13 mm for the flat-face side. Order 911 mm wide.
An angle on both sides: wall to wall is 900 mm. Take off 2 mm twice. Order 896 mm wide.
You do not need the angle in your hand to measure. Measure to the wall or frame it will stick to and the sum above does the rest.
Add the angle when you order. There is a tick box for it when you configure your screen. A length is 2.4 m of angle with tape already on it, supplied as four 600 mm pieces so it travels with the screen. One length does one side of any screen, or two sides that add up to 2.4 m or less.
Step 03
A window behind a ranch slider
A magnetic screen usually fits on the window a ranch slider slides across. There are two things to check.
1. The gap behind the door
Slide the door across in front of the window. Measure from the face the screen will sit on to the back of the door.
- AThe gap to measure. From the face the screen sits on to the back of the sliding door.
- BThe sliding door, slid across in front of the window.
- CThe window frame, seen from the side.
- DThe screen. About 8 mm deep, and about 22 mm deep at the two bottom corners.
The screen needs about 8 mm at the top and about 22 mm at the two bottom corners, where the corner pieces are deeper.
Close to 22 mm, or a little under?
Do not rule it out. Send us the gap and some photos and we will tell you whether it will work before you order.
2. The sides with no flat face
A window behind a ranch slider nearly always has at least one side with no flat face, where it meets the wall or the door frame. That side needs a plastic angle, and the angle changes the size you order.
Photos get you a sure answer
Send one photo of the whole window from straight on, a close-up of each side, and one with the door slid across. Add your measurements and we will confirm the sizes with you.
Latches, clips and drip trays
The top edge may tuck into a drip tray if the screen can still be lifted out. Avoid trapping the sides and bottom. Small sections of frame tape can be cut out where a latch closes and where the supplied top clips sit.
Step 04
Order the screen
- Enter the finished heightThe size you worked out, not the opening. Recheck the top and bottom.
- Enter the finished widthThe size you worked out, not the opening. Recheck the left and right.
- Choose from the current frame optionsIf a colour is not displayed by the configurator, it is not available in the self-serve range.
- Choose the meshStandard charcoal insect mesh (18/14) balances everyday fly and mosquito protection with airflow and view. Fine SOL1818 mesh has a tighter 18 × 18 weave for midges and sandflies, with some reduction in airflow.
- Review the cart lineName the opening clearly and confirm the millimetres before placing the order.
Step 05
Fit the screen
Isopropyl alcohol
With a clean lint-free cloth, for the final wipe of every face.
Sharp cutter
For neat tape gaps around latches and the supplied top clips.
Keep every magnetic strip in the supplied order and orientation
The tape arrives aligned to the screen. Flipping or reversing a strip changes the polarity and can make the screen sit skewed or hold poorly.
- Fit any plastic angle first. Clean the surface it sticks to, then peel the tape and press the pieces on one after another, butted end to end, with the face lined up with the flat faces on the other sides. Trim the last piece to length.
- Dry-fit. Hold the screen at the opening. Confirm size, placement, latch clearance and the supplied tape orientation before exposing adhesive.
- Clean and dry. Wipe each mounting face thoroughly with isopropyl alcohol and a lint-free cloth. Let it dry completely. Avoid a very cold morning.
- Fit the top strip. Remove it from the screen without flipping it. Peel back a short section of liner, align the edge, then peel and press progressively.
- Fit the tightest side. Install the side with the least usable face next, square to the top and parallel with the opening.
- Use the screen as the alignment guide. Snap it onto the first two strips and position the remaining side and bottom tape against the matching edges.
- Tension gently. On the opposite side, pull the coil edge just enough to make the mesh taut while peeling the liner and pressing the tape. Repeat at the bottom.
- Create required gaps. Mark and neatly remove tape where window latches close. Fit the two supplied top clips around one-third of the way in from each side, cutting matching gaps in the magnetic tape.
- Press the full perimeter. Remove the screen and press firmly along every part of the bonded frame tape with a clean cloth.
- Refit and test. Push the top into the clips, let the magnets snap home, and confirm the screen sits square and the window operates cleanly.
Step 06
Care and troubleshooting
Routine clean
Lift the screen away using the pull point. Use a soft cloth or soft brush on the frame and mesh.
Deeper clean
Hose the screen outside if needed, then let it dry completely before refitting.
Screen sits skewed
Check that no magnetic strip was flipped, reversed or moved out of its supplied order.
Tape lifts
Remove contamination, let the surface dry, and press firmly. Use the enquiry form if the substrate or adhesive has failed.