Cedar Shake Roof Cleaning: How to Clean and Preserve Wood Shingles
A cedar shake roof is one of the best-looking roofs on a Lower Mainland home and one of the most demanding to look after. Cedar is organic, so moss and algae do not just sit on it, they feed on it and hold moisture against the wood, which is exactly what rots and splits shakes over time.
Here is how cedar roofs are cleaned so the moss comes off and the wood is preserved, not damaged.
Why cedar needs special care
Unlike asphalt or tile, cedar is a living-once material that swells, dries and ages. Moss and algae keep it damp, and constant damp leads to rot, cupping and splitting. At the same time, cedar cannot take aggressive cleaning: high pressure tears the soft grain, blasts out fibres and can split shakes outright.
So cedar sits in a narrow lane. It genuinely needs cleaning to survive our climate, but only by a gentle method that respects the wood.
Gentle removal and treatment
The bulk moss is removed carefully by hand and soft brush, working with the grain and never gouging. Then a treatment appropriate for wood is applied to kill the remaining moss, algae and lichen at the root, so it does not simply grow straight back. High pressure is never used on cedar.
Because the growth is killed rather than blasted off, the roof keeps clearing over the following weeks and stays clean far longer, which means fewer cleaning cycles on a roof that does not enjoy being disturbed.
Preserving the roof afterward
Keeping a cedar roof healthy is mostly about keeping it dry and clear: trim back branches that shade and drip on it, keep the gutters flowing so water is not backing up at the edges, and clear debris out of the valleys where it traps moisture. A maintenance treatment every couple of seasons keeps moss from re-establishing.
Cedar roofs are quoted per property because age, pitch and condition vary so much. If your shakes are already cupping or splitting, an honest look will tell you whether cleaning preserves them or whether the roof is nearing the end of its life regardless.