Cedar Shingles, Cedar Shakes
The vast majority of wood roofing shingles, as shown in Figure 1, are manufactured from western red cedar (cedar shakes) because of its insect resistance and overall durability. Because the cost of western red cedar has increased dramatically over the last 10 years some of the wood shingles that are being marketed are made from other fir species, such as pine, and then treated with a preservative.
Figure 1 - Cedar shake shingle roof
To clarify the terminology, wood shingles have a smooth finish, whereas cedar shakes are rough-hewn and provide a more rustic appearance. Wood shingles and cedar shakes are sold in lengths of 16, 18 and 24 inches, in random widths.
Installing A Cedar Shake Or Shingle Roof:
Most finished roofing materials can be installed on any style of roof decking.
However, in order to avoid having the cedar shingles become soggy, wood shingles are best installed on 1" x 6" boards, spaced an inch or so apart to allow for sufficient air circulation and drying, as shown in Figure 2 and 3.
Figure 2 - Installation of cedar shingles on boards
Figure 3 - 1" X 6" boards installed on roof for cedar shingles
Cedar shakes on the other hand, are usually installed with alternating layers of tarpaper or roofing felt to ensure a true weather-tight installation as shown in Figure 4.
Figure 4 - Installation of cedar shakes on layers of tarpaper
If this is a remodel project rather than new construction, you can install shingles or shakes directly over asphalt shingles or previously installed wood shingles or shakes.
Wood Shingle / Cedar Shake Problems:
As with most roofing material the longevity of the roof is based on numerous factors, including the climate, weather and the pitch of the roof and because of those variables wood shingles and cedar shakes can have a life as short as 15 years or as long as 40.
With a low pitch roof water, snow and ice can accumulate and cause the wood shingles or cedar shakes to deteriorate.
If you have cracked, curled, broken, split or damaged wood shingles or cedar shakes, you will most likely have water ingression. Always inspect your roof after any major storm or hurricane for shingles that may have lifted as a result of the wind and rain.
In many cases, it is hard to see broken shingles or shakes. In conjunction with the roof inspection you should check the attic for signs of moisture. With wood shingles and shakes it is relatively easy to replace a few damaged units.
Wood Shingle / Cedar Shake Repair and Replacement:
If you identify split shingles or shakes they can be repaired by pushing the piece that is split back together and nailing them to the roof deck.
Seal the crack and cover the nail heads with a roofing cement to create a weather tight seal.
If you have shingles that have lifted from the roof deck, reseat the old nails and add additional nails. Then seal all the nail heads with roofing cement.
Figure 5 - Removing wood shingle or cedar shake nail using a shingle ripper tool.
Figure 6 - Replacing wood shingle or cedar shake.
If the wood shingle or cedar shake is damaged beyond repair and it must be replaced you must first remove as much of the old wood shingle or cedar shake as possible. If necessary use a chisel to split the wood shingle along the grain to create smaller pieces which will be easier to remove. Next, raise the wood shingle or cedar shake that is above the damaged wood shingle or cedar shake to gain access to the nails that held the old wood shingle or cedar shake to the roof deck. These nails must be removed, using a shingle ripper tool or hacksaw blade or, cutoff flush with the roof decking. Care must be taken to avoid damaging any roofing material under the shingles or shakes.
Place a new shingle or shake, with the width about 1/2 inch less (1/4 inch either side) than the shingle or shake that was removed (this allows the shake or shingle to expand with changes in humidity) into position and using a wood block and hammer push the shingle or shake into the vacant space until the end rests about 1/4 inch below the other shingles or shakes, as shown in Figure 6.