A wood roof is made up of several thousand pieces of wood called shakes. Shakes come in a number of different sizes and grades, but the most common for residential single family homes is #1 grade medium sized. Medium sized shakes are usually twenty four inches long, and they are cut tapered, meaning that the bottom or “butt end” is thick and as you move up the length of the shake it gets thinner and thinner, all the way to the top. Now the shakes are laid in rows, starting at the bottom of the roof (right above the gutter), then progressive rows are laid overlapping the first row. The desired distance between rows is commonly ten inches. As the rows move up the coarse of the roof, they are staggered, so that the water will not be able to go under the rows below. At the top of the roof is the ridge cap, this is the weakest part of the roof, and usually wears out first.
Now that you know the layout of the roof, its time to learn what to look for. Since the ridge cap usually wears out first, it’s a good idea to plan on replacing it. To do so, first it must be removed. The easiest way to do that is to start at the last piece that was installed, and remove from that end working your way to the first piece that was installed. Once removed, all old nails or staples need to be hammered back down. Then start laying the ridge caps at one end, nail each side twice. Be sure to nail far enough back, so that the next ridge piece covers the nails. The desired overlap is ten inches.
Once the ridge is installed, you will need to inspect the field of the roof for any signs of damage (such as missing shakes, broken shakes or split shakes). One of the most important things to look for is exposed felt paper. The underlayment is not made to be exposed to the elements, so where ever that you can see it is normally bad. The top reasons for exposed underlayment are, Missing shake, broken shakes, split shakes and something know as burn through. Burn through happens when the water that is shed from rows above, drip on to the thin part of the shake, in between the two shakes above. Over time the flow of water can wear away that thin area of wood, exposing the felt underlayment. When this happens, there are two different ways to go about repairing it. Both are acceptable, the first way is to replace the entire shake. The second way is to insert a piece of sheet metal, under the shakes above, but over the top of the shake with the burn through.
Once all the ridges are installed, and the necessary repairs are made in the field of the roof, it’s a good idea to check out the flashings. You will want to check the sealant around all vent pipes and chimney counter flashings. If they are cracked, a good silicone caulking is what is called for. After the pipes and flashings are sealed, paint the flashings and particularly the valley metal with quality rust inhibitor paint such as rustoleum. After you have completed all that, your cedar shake roof should be in good shape for another three to five years. If you run in to any difficulty, one of our representatives would be happy to assist you.