Cedar Roof Cleaning Questions we’ve been asked.

Can moss buildup cause my roof to leak?

Heavy moss can cause water to back up the roof enough to run over the top of the shingles. The buildup should be removed. Moss retains soil and moisture that could harm the wood over time.

My cedar shake roof is surrounded by tall fir trees and the needles accumulate in the spaces between the shakes. Should I have these cleaned out periodically?

Yes, it is a good idea to have a professional clean the debris off your roof. Cedar needs to breathe, and therefore any accumulation of needles, branches, leaves and dirt will affect its lifespan.

What can I do to prevent moss buildup on my cedar roof?

Keep all debris and buildup cleaned off. Trim all branches that overhang your roof and make it shaded. Have you roof cleaned every 5-7 years.

What will zinc or copper napthanate do to my roof?

A zinc or copper napthanate are supposed to preserve your cedar roof and to retard future surface growth. We personally have never seen them benefit much and do not recommend them.

Can I power-wash my cedar roof?

Power-washing can seriously damage a cedar roof.  We use low pressure to clean your cedar shake shingles. The same amount of pressure that comes from your garden hoses.

Check the CSSB’s Care & Maintenance Brochure for care and maintenance guidelines.

Should I seal my cedar roof to keep out moisture?

No. Never seal your cedar roof. Sealing the roof will lock in moisture that would otherwise naturally evaporate during normal weather conditions. Cedar needs to breathe and thus a water repellant type product, rather than a water proofer is the best route to follow. See the CSSB’s Care & Maintenance Brochure for complete topical treatment product guidelines available from the CSSB.

Can I use oil on my roof?

Yes, it is a component of a proper cedar roof maintenance product. Cedar Shake Roofs have a natural 3% oil content and need to maintain that. We have oil added into our special solution. Check the CSSB’s Care & Maintenance Brochure for guidelines. Paraffin is sometimes used as a carrier for active ingredients and will usually weather away within six months.