Pacific Northwest
Stone care in Seattle
Cool, very wet, low UV, persistent moss and algae pressure.
Constant moisture is the defining challenge — outdoor stone grows moss and algae, and indoor stone in poorly ventilated bathrooms can stay damp for days.
Best stones for Seattle
Recommended
- Slate
- Bluestone
- Granite
- Quartzite
Use with caution
- Sandstone (outdoor)
- Limestone (outdoor)
Common local problems
- Green algae and moss on patios and entryways
- Persistent grout mildew in showers
- Sealer wash-off on north-facing stone
Care tips for Seattle
- Treat algae with diluted hydrogen peroxide; rinse thoroughly
- Run bath ventilation continuously, not just during showers
- Reseal exterior stone yearly — sometimes twice on north faces
Sealing schedule
Recommended cadence
Outdoor: every 9–12 months. Indoor wet: every 9–12 months.
Frequently asked questions
Is bleach safe for moss removal?
Avoid bleach on calcareous stone. Use 3% hydrogen peroxide or an oxygenated stone-safe biocide.
Other cities
General guidance only. Always test a small inconspicuous area first and consult a local stone restoration pro for serious damage.