How Windows Keep Santa Ana Wind Dust Out of a San Bernardino House

Everyone assumes a closed window is a sealed window. After one night of Santa Ana winds in San Bernardino, the dust line along the sill says otherwise, and san bernardino replacement windows earth liberation front covers the sealing details in order. Most of that dust comes in through a handful of gaps that repair or replacement windows can close.

Where the dust gets in

Wind pushed down through Cajon Pass loads the face of a window with steady pressure and gusts. Air then finds the weakest path: the bottom of a slider track, the gap at the meeting rail of a double hung, the corner where a sash meets the jamb. Fine grit rides in with that air and settles on the sill within hours.

Weatherstripping that holds up

Pile weatherstripping, the brushy strip common on sliders, blocks airflow but lets the finest dust through. A bulb or fin seal that compresses against a flat surface does better. In dry heat, soft foam seals harden and crack in a few seasons, so a seal made of flexible vinyl or thermoplastic holds its shape longer.

Sash fit and lock pull

A good lock does more than keep the window shut. It pulls the sash tight against the seal, closing the gap that wind opens. A worn lock on an old aluminum window leaves the sash a sixteenth of an inch loose, and that is enough to whistle. A casement sash compresses against its seal as the handle turns, so it resists pressure better than a slider.

Sill, jamb and frame joints

Dust also enters around the window, not only through it. Dried caulk at the stucco joint, an open gap between the frame and the rough opening, or a missing sill pan lets air slip behind the trim. A replacement should be shimmed square, foamed with a low expansion product and sealed outside with a flexible sealant.

Cleaning and keeping the seals working

Grit in a track grinds the seal like sandpaper. Vacuum slider tracks and weep holes after every windy stretch, then wipe the seal with a damp cloth. Weep holes clogged with dust trap water, which shows up as stains under the sill and swollen trim over time.

When replacement beats repair

A new seal can fix a loose sash. A frame that has warped, or a track worn through, cannot be fixed with a strip. On homes in Del Rosa and Verdemont with thirty-year-old aluminum frames, a vinyl window with an interlocking meeting rail usually closes the gap that repair never will.