Whatcom County Home Inspector (King of the House) Composition Shingles

Here in Bellingham and Whatcom County, it is common, with composition shingles, to find that some of the self-sealing strips have failed to seal, or melt, properly. When new shingles are put in place, if the weather is warm, the tar strips should seal. That holds the front edges down so they are not so prone to being blown off in the wind. When the inspector finds that most of the shingles easily lift

That usually means that it is an older roof, and the strips have failed, given up the ghost, or less likely, the roof is new and the strips have yet to melt and seal. In my experience, the latter is not the case very often. When the self-sealing strips have failed, a few beads of tar can be put under the edges of the shingles, assuming they are still in decent shape, and that goes a long way as far as making them less likely to blow off in the wind.