Clean Freaks Co. Wool and silk-blend rug care in Los Altos Hills.

Wool is a protein fiber with a scaled cuticle and a natural lanolin sheen, and it behaves nothing like the tufted synthetics a general carpet crew is equipped for. It swells when wet, it is alkaline-sensitive, and its vegetable or older aniline dyes can bleed or brown when the water chemistry, temperature, and dwell time are wrong. A hand-knotted rug also has a cotton or wool foundation and hand-knotted fringe that are structurally part of the piece — not trim — so a rushed surface pass drives soil deeper into a dense pile rather than lifting it out.

Los Altos Hills adds its own load. Homes sit on graded hillside lots ringed by coast live oak, and the fine, mineral-rich soil turned up by cut-and-fill grading and unpaved margins travels indoors as a gritty dust that settles to the base of the pile, where it abrades wool from below. Oak shed compounds it — leaf litter, spring pollen, and aphid honeydew carry tannins and sugars that set into the fiber and feed browning if they are left in place through a damp season.

Then there is the fog. The marine layer and canyon fog keep ambient humidity high through long mornings, so a wool rug that is over-wet or dried flat on a hillside floor stays wet too long — the exact setup for cellulosic browning, dry rot in the cotton foundation, and lingering odor. That is why this is an immersion-and-controlled-dry process, not a same-day steam pass.

1. The rug is dry-dusted before any water touches it — flipped and air-dusted from the back to release the fine hillside grit lodged deep in the knots, since that mineral soil turns to abrasive mud the instant it is wetted.
2. Dyes and fibers are tested for colorfastness and pH tolerance, then the piece is immersion-washed off-site in wool-safe, near-neutral chemistry at a controlled temperature — the only reliable way to flush set oak tannins and honeydew without shocking vegetable or aniline dyes into bleeding.
3. Water is drawn out by wringer or centrifuge and the rug is moved to a heated, air-moving drying room rather than left on a fog-damp hillside floor, so the wool and its cotton foundation dry fast enough to head off browning, dry rot, and odor.
4. Fringe, foundation, and any weak or previously repaired areas are groomed and finished by hand, and the partner flags moth activity or dry-rot vulnerability before the rug is returned and re-laid.

• Late spring, once oak pollen and catkin drop have finished — clearing the season’s tannin-heavy shed before summer keeps it from setting into the pile through the dry months.
• Ahead of the winter wet season — a rug washed and fully dried before the Peninsula’s rainy, low-light months is far less likely to hold tracked-in moisture and mud through the damp stretch.
• After a run of heavy marine fog — if a wool rug begins to feel clammy or smells musty in a fog-prone room, that is trapped humidity, and it should be dried and washed before browning or dry rot begins.
• Following driveway grading, hardscape, or landscape work — hillside construction pushes fine mineral dust indoors, and getting it out of the pile early keeps the grit from cutting the fiber at its base.
• Every few years for a fine hand-knotted piece on principle — deep-set soil stays invisible at the tip of the pile long before it is doing damage down at the knot.