DIY Shake Roof Inspection: How Much Life Is Left?

In this article we teach you how to inspect your shake roof to determine its remaining life. You will come away with the understanding and confidence to decide whether your roof is in a failing state or has years of life remaining. We begin with a ground inspection.

Ground inspection

From the ground we can often determine the condition of a roof. It is very typical that by the time a customer decides the roof is in bad enough shape to call us for an estimate, the roof has been failing for years without their knowing. They haven't experienced any leaks that they know of, but the roof substrate has been suffering delamination for years. Once the roof is removed, the rotting substrate must also be replaced in the areas that leaked, adding cost that could have been avoided.

We recommend walking around the whole building and visually inspecting each roof deck, noting the condition of the shakes or wood shingles. South facing decks face the sun the longest each day and will typically be in worse shape than the other decks.

Cupping and curling

From the ground, determine whether a good number of shakes or wood shingles are cupping or curling.

• Cupping is when the two long edges of the shake begin to lift off the roof deck and form a U shape when you look at the shake head on.
• Curling is when the thicker bottom edge of the shake begins to curl up.

If your shingles are starting to cup or curl, the roof may be in the beginning stages of failure.

Hip and ridge

If the hip and ridge pieces are separating or missing, or the staples that hold them down are working themselves up and out of the wood, the roof is in a failing state and should be replaced. A new hip or ridge shows how the two pieces that make up the cap lap tightly at the edges to keep out moisture. When that lap opens up, moisture gets in.

On the roof

In some situations the shakes or wood shingles look fine from the ground but the hip and ridge pieces are failing. It is time to go up and assess the roof more thoroughly.

A note of caution: walking on your shake roof can damage it with your body weight. If the shakes or wood shingles are cupping or curling, you will most likely crack them if you step on them. In that case, stand at the top of a ladder and do a visual inspection of the south facing deck first. Look for the following.

• Split shakes: the shake or wood shingle breaks lengthwise and creates a new seam. Often the new seam sits very close to the seam it is supposed to cover. Some shakes are starting to crack but haven't split through, but in many cases the new seam is right over the seam below, and moisture can pass through the crack and get into the system.
• Fungal damage: fungus can eat away at the cellulose fibers. This is a common reason shakes break off in heavy wind. Heavy snow can exert great force on these weakened shakes and pull them loose.
• Shake liner condition: the asphalt shake liner between courses is still dark black when it is new, which may mean it has only been through one summer season. As the liner weathers and is damaged by UV rays, it cracks and flakes away, exposing the wood substrate below.

Substrate and the cost of surprises

Substrate can be expensive to replace and places an extra cost burden on homeowners. Roofing contractors cannot estimate the cost of damage under the old roof until the shake roof is torn off and the substrate is bare for inspection. Most roofing contractors estimate a per square foot price for substrate repairs and make the repairs on a discovery basis.

Even roofs with very little cupping or curling can be deceiving. If the roof is gray in color, it may be very brittle and shouldn't be walked on. If you know someone who can fly a drone, have them record a slow fly-over of the surface. It may help you do an inspection without causing damage.