A Magnetic Screen for Arched and Round Top Windows

An arched opening is the one shape no stock screen covers. Screen frames are cut square, spline channels do not follow a curve, and the half screen that fits the window below the arch was never made for the arch itself. That is why a round top window is so often the only unscreened opening left in a house where everything else is covered.

How a Made to Measure Arched Screen Works

The panel is cut to the curve you measured rather than to a size off a list. Magnetic strips run around the whole perimeter and follow the arch, and the matching adhesive strip goes on the frame or the jamb, so the screen sits against the actual shape of the opening instead of boxing it into a rectangle. Nothing is drilled, no tools are needed, and it comes away at the end of the season without marking the trim.

Full mesh or central splits

This is the option people ask about most. A full mesh panel is one continuous piece with no opening in it, which is the right choice for a window you look through rather than walk through: it is the tidiest and there is no seam across the glass.

A central split adds a magnetic closure down the middle, so the panel becomes two halves that part when you walk through and pull themselves shut behind you. Choose one split for an arched door or a round top patio door you use daily. Choose two or more on a wide arched opening, where splits also break a very large panel into sections one person can handle, fit and take down alone.

Measuring an Arched Opening

This is what decides whether the screen fits, and an arch needs one more measurement than a rectangle. Spend your time here rather than on the color.

The three measurements

First the overall width at the widest point. Second the total height, from the sill to the highest point of the curve. Third, and this is the one people forget, the height to the spring line, meaning the point up each side where the straight part ends and the curve begins. Without that third number, two openings with identical width and height can be completely different curves.

Half round, segmental and elliptical

A half round has a rise of exactly half the width and no straight section above the spring line. A segmental arch is a shallower curve where the rise is much less than half the width. An elliptical or gothic head is a different curve again. The three measurements above describe all of them, which is why we ask for numbers rather than for the name of the arch.

When the arch is not regular

Older and site built arches frequently are not. If the two sides do not match, or the curve is visibly flatter on one side, make a template: tape kraft paper or thin cardboard across the opening, run a pencil around the inside of the frame, and measure from that. It takes fifteen minutes and it is far more reliable than trying to describe an irregular curve in numbers.

Fitting Without Drilling

The adhesive follows the curve, so what it needs is a continuous, flat, clean surface all the way around the opening including through the arch. Check that before ordering: a deep jamb, a heavy molding profile or a drywall return through the head are all worth knowing about in advance. Clean the surface with rubbing alcohol rather than a household spray that leaves a residue, and avoid fitting in direct sun on a hot afternoon, because adhesive likes warm and does not like hot.

Made to Measure Cannot Be Returned

A panel cut to your curve fits nobody else's opening, so unlike a stock size it cannot come back. That is not a policy quirk, it is what made to measure means, and it is the reason to measure twice and write the numbers down rather than trusting memory between the ladder and the keyboard. If your opening is irregular, set into a deep jamb, or has hardware in the way, tell us with the order instead of rounding the numbers and hoping.

Arched Windows in Canadian Homes

The round top window here usually sits high in a gable wall, above the main glazing of a great room or over an entry. In a chalet or an A-frame it is often part of the lakeside or slopeside wall, set well out of reach. Wherever it is, it is high, which means it is doing most of the venting on a warm evening and it is the hardest one to service.

The screens come down every fall

Canadian households already take their screens off before winter, and for good reasons: an interior screen traps moisture against cold glass and encourages mildew, it holds snow against the window, and a winter of wind and ice will bow or tear it. On a high arched window that chore is genuinely awkward with a rigid frame. A magnetic panel comes away by hand, lies flat in a closet, and goes back up in the spring without tools or hardware.

Black flies, then mosquitoes

Black flies emerge around mid May and peak from late May through late June across southern Ontario, a week or two later in cottage country, and they cluster near clean moving water. Mosquitoes take over through July and August. That makes April and early May the sensible window to order, because a made to measure panel is produced after the order rather than pulled off a shelf.

One honest caveat: standard 18x16 mesh, which is what we use, is not fine enough for black flies. Stopping those takes 20x20 screening we do not make. Against mosquitoes, houseflies and wasps it is exactly the right tool.