Moss, lichen, and biological growth removed from Palo Alto cedar shake roofs — soft wash only, no pressure washing that splits shake or drives water into the wood grain. Owner-operated. Free estimates.
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Palo Alto's mature tree canopy creates persistent shade on cedar shake roofs, and the peninsula's coastal fog keeps wood surfaces damp well past midmorning — the combination that drives accelerated moss and lichen growth on cedar's naturally porous, textured surface. Properties on the western edge of the city and those with significant bay laurel, oak, or redwood overhang see particularly heavy biological pressure. Moss retains moisture against the wood surface, and prolonged moisture contact is the primary driver of rot and premature shake failure.
Cedar shake is split or sawn wood — porous and fibrous in structure. High-pressure washing forces water deep into the wood grain, saturating the shake and dramatically accelerating moisture-driven rot. Pressure also splits individual shakes, dislodges tabs, and strips the natural oils that provide weathering resistance. The correct method is soft wash: a biodegradable treatment solution applied at low pressure that kills moss, lichen, and biological growth at the root without driving water into the wood or causing mechanical damage.
Lichen is harder to remove than moss — it attaches directly to the wood surface and its acids slowly etch into the cedar grain. Soft wash kills lichen at the attachment point; dead lichen releases from the surface over subsequent rain cycles rather than being forcibly stripped while alive. This is the correct approach — forcing removal of living lichen tears the wood surface.
Ready for a free Palo Alto cedar shake roof wash estimate? Call or text — same-day response.
Cedar shake condition assessed before any treatment — individual cracked, split, or missing shakes noted. Moss density mapped by roof section. Lichen locations identified. Any flashing gaps or visible water entry points reported to homeowner before work begins.
All plants, shrubs, and lawn areas below the roofline pre-wetted before any treatment solution is applied. Pre-wetting dilutes incidental overspray and protects Palo Alto landscaping, which can be extensive on shaded properties.
Leaf debris, organic matter, and accumulated growth cleared from cedar valleys and gutters before treatment. Clearing debris first allows the treatment solution to reach the shake surface directly rather than being absorbed by leaf litter.
Biodegradable treatment solution applied at low pressure across the full cedar shake surface. Solution penetrates and kills moss, lichen, algae, and other biological growth at the root and attachment point. Dwell time held until penetration is complete.
Roof rinsed at low pressure — no concentrated high-pressure work that could split shake or force water into wood grain. Rinse removes loosened surface material and confirms treatment coverage across the full roof.
Cedar condition verified post-rinse. Any shake damage, open valleys, or concerning areas noted and communicated. Landscaping below rinsed to clear residue. Any previously flagged issues documented for homeowner reference.
Palo Alto cedar shake roof wash — soft wash, no splitting, moss and lichen killed at the root. Free estimates.
Same result on your Palo Alto cedar shake roof. Call or text for a free estimate.
Straight answers for Palo Alto homeowners. Don't see yours? Call or text (408) 598-1857.
No. High-pressure washing forces water into the wood grain, splits shake, and accelerates rot. Soft wash — biodegradable solution at low pressure — kills biological growth without mechanical damage to the cedar surface.
Palo Alto's mature tree canopy creates persistent shade and the coastal fog keeps wood damp through midmorning. Cedar's porous surface retains moisture, making it ideal for moss, lichen, and algae to establish and grow rapidly.
Moss retains moisture against the wood surface, keeping shake wet far longer than it would otherwise stay. Prolonged moisture contact drives rot — the primary cause of premature shake failure. Regular cleaning extends cedar shake roof lifespan significantly.
Every 3 to 5 years depending on shade. Properties with heavy tree canopy will be closer to 3 years.
No. Biodegradable solution is formulated for wood surfaces. Landscaping is pre-wetted before treatment and rinsed after — standard practice on every job.
Yes. Bull Run Exterior Wash LLC is fully licensed and carries general liability insurance on every job.
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