Text by Sabrina Kahler

With all the other home improvements you're making this summer, it might be a good idea to add pressure cleaning to your wood shake or shingle roof. The restoration process can improve appearance and durability for years to come.

The warm weather is the right time to do it, too. “Forty-five degrees or above is needed to apply treatment to the roof,” said Tim Cross of Pro WoodCare in Germantown.

Treatment is actually the last of the three steps of wood restoration. After an evaluation of the exterior wood surface is completed, a restorative detergent is applied and the roof is cleaned to remove mildew, moss, debris and dead wood fiber using pressure cleaning equipment.

An inspection and repair follows the cleaning process. “We go through the roof, depending on the age and construction of it,” said Cross. If the roof is fairly new, and is stapled rather than nailed, a problem occurs where the shakes can move, curl, cup, expand or contract. The staples might loosen or pull themselves out. “When that happens, we resecure the shingles, and replace the bad ones and put new ones in,” he said.

The preservative treatment is applied as the final stage. “We use an oil-based preservative. A water-based preservative doesn't protect the roof from the sun and the rain - it only retards the fungus,” Cross explained. “It's the sun and the rain that causes most of the damage.” A variety of colors can be put on the roof, Cross stated, but most people have a clear treatment put on that eventually turns a silver or gray color. “Once treated, it will never go back to the original color,” he said.

A new roof may need treatment in as little as six months from when it is constructed. “If a roof is treated at the time of construction, it can eliminate some of the cleaning process,” Cross said.

Once the three stages of pressure cleaning are completed, a roof may need to be treated every three to five years. “It will take six months to a year to weather,” he said. The whole process doesn't need to be done every three to five years; the roof just needs to be retreated with the preservative.”

How long does this process take? On an average roof, the cleaning could take a three-man crew two full days. The repair and preservative takes one day. “We can clean the roof and it can sit for a month if the weather is inclement, before anything would happen to it. We need it to be 45 degrees to seal,” Cross said.

The benefits of this restoration process is that it can double or triple the life of your roof. “If a roof is untreated, a cedar roof could last 12 to 15 years. With treatment it can go 50 years and beyond,” he said. The average cost to get a whole new roof is $20,000 to $25,000. A telltale sign to see if your roof needs restoration is if the shingles are starting to curl or cup.