Cedar-Shake Roof Maintenance Is Costly, But Worth It

Q: Two years ago I spent a lot of money replacing my cedar shake roof. I want this one to last. What can I do to extend its life?

A: The quality of roofs varies tremendously, even on homes built concurrently, because of the differences among individual trees and the mills that supplied the material. The differences are even more obvious when roofs are not maintained. The ridge caps usually are the first thing to fail. They tend to come apart at their stapled seams after 10-12 years and love to sail off the roof when the wind picks up. They are also most prone to deterioration. Expect to replace many in the life of the roof. Splitting, cupping and twisting claim quite a few individual shakes over the years. Some simply fall out of their original position. Overall deterioration and soft wood sound the death knell for a cedar roof.

Good roof life expectancy starts with a well-ventilated attic or rafter space. Ideally, this consists of eave/soffit vents and continuous ridge vents and/or extensive use of mushroom-style roof ventilators at the roof peak. In reality, most homes do not have this. Ventilation carries away damaging moisture and heat in the summer by allowing it to exit at the top. (Gable end vents allow for cross venting but are not the most efficient way for heat to escape.)

Keeping the roof clean and treated will vastly increase its life. Colored preservative treatment also makes the inevitable patches look original.

There is an industry group that believes that walking on the roof causes more damage than the good done cleaning it. Maybe so in a laboratory, but in this part of the world we have big trees and they dump tremendous amounts of debris.

I saw a shake roof less than 10 years old with ferns growing out of the gutters, and tall weeds, small alder trees and moss covering the surface. There was probably two inches of dirt over the whole roof. Needless to say, that roof was trashed. By not walking on your roof, you can't thoroughly inspect it for the aforementioned defects and are at risk of having it leak eventually. Do not walk on cedar roofs without strap-on spiked shoes called roof corkers. Rental shops have them, or they are fairly inexpensive to purchase.

Many roof cleaners use compressed air or chemicals rather than pressure washers. Pressure washers, if put in inexperienced hands or held in one position too long, can quickly create gouges in shakes. Do not use water pressure if you are not experienced or if the roof is older or softer. Having a professional clean and treat your shake roof every few years may be expensive, but will pay back handsomely in extended life and peace of mind. One undetected, ongoing leak could be more expensive than many years of roof cleaning.

Q: I have some minor cracking in my concrete walkway and want to know what I can do about it.

A: There are epoxies, patching cements and sealers that can be used to patch concrete. Problem is, you are not addressing the reason the failure has begun and chances are it will continue to get worse. Patching will keep water from entering and possibly worsening the cracking, but when movement resumes the patch material will likely fail. The concrete is moving with changes in temperature and humidity.

This discussion assumes the underlying soil beneath your concrete is stable, rebar was placed and a proper concrete mix was used. But you must realize that concrete is inflexible and cracks. Always. The trick is in controlling where the cracks will occur and hiding them from view. This is achieved by using control joints and expansion joints.

Municipal sidewalks are the best example: Control joints are the troweled marks across the sidewalk every four feet. Expansion joints are the physical breaks containing what looks like tar impregnated cardboard every fourth control joint or so. At your home, expansion joints are usually 2x4s. The cracking occurs at expansion and control joints where it is mostly hidden and "controlled."

Today, typically in residential construction there is no area greater than 10 feet in any direction without joints. This is an improvement over 20 years ago, but still not enough to eliminate random cracking. Control joints also need to be put at outside corners and penetrations into slabs as they are very consistently areas where cracking occurs.

Ask The Expert answers readers' questions every Saturday. Send questions to Ask The Expert, Seattle Times, P.O. Box 70, Seattle, WA 98111, or call 206-464-8514 to leave your questions on Ask The Expert's recorded line. E-mail address is dhay@seattletimes.com

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