The sprinkler head that cost a window

The call

A Brunswick Forest client called about three ground-floor windows on the same elevation that had 'gone cloudy' while the rest of the house stayed fine. That pattern is diagnostic on its own. Salt and pollen do not pick three windows in a row and leave the fourth alone. Irrigation does.

A rotor head about eleven feet from the wall was throwing the tail of its arc onto the lower third of those three panes, four mornings a week, for three years.

Why irrigation water is worse than rain

Well water and municipal water in this part of Brunswick County carry dissolved calcium and magnesium. When a droplet lands on hot glass and evaporates, the water leaves and the minerals stay. Repeat that a few thousand times and you have a dense deposit bonded to the surface.

Rain does not do this because rain is close to distilled. It is precisely why our exterior work uses deionised water: water with nothing in it cannot leave anything behind.

What the test patch showed

We ran a free stage test on the worst pane. The dissolver and white pad took the upper band back to clear, which put that section at stage 1. The lower band, where the spray landed most directly, did not respond. Under a low-angle light you could see pitting, and you could feel it with a fingernail.

That lower band was stage 3. Polishing it enough to clear the pits would have removed enough glass to distort the view through the pane. We recommended replacing one unit and polishing the other two, which came to roughly half of what a full restoration quote would have been.

• Stage 1, surface deposit: dissolver and pad, no glass removed
• Stage 2, early etch: cerium oxide machine polish, microscopic glass removal
• Stage 3, deep pitting: replace the unit, do not polish

The fix that mattered most

Adjusting the rotor arc took about twenty minutes and cost nothing. Without that, the replaced unit would have been back at stage 1 within a summer and stage 2 within three.

If you have irrigation, walk the property during a cycle and watch where the water actually lands, not where it is supposed to land. Wind drift on a coastal lot moves a spray pattern further than most people expect.