I’m a new owner of an old house in Berkeley. It was built in 1912 and I have no reason to believe that once-natural-now-painted shingles have ever been replaced. Several shingles near the southern roof line have fallen off the house.
So my question to you is: what’s the lifespan of a shingle? Any tips on what to look for in a shingle-contractor? What’s the biggest mistake/oversight people make about shingled-houses?
Great question. My experience is that the life of shingles varies widely and I’ve seen shingle fail at 20 years and also survive to almost 100 years. Factors include the species and quality of the shingle (A-grade Cedar seems to perform very well), exposure to sun, proximity to trees, moisture in the immediate environs, compass orientation and maintenance. Maintenance can include anything from brushing loose material off, through treatment with preservatives such as Penofin (highly recommended) to painting, which works but may be an aesthetic issue for some.
Painted shingles do seem to perform really well, if you keep them thoroughly painted. I think it’s possible for your painted shingles to last for 100 years if you can paint properly and regularly.
For those who have unpainted shingles, I recommend that they be brushed free of any foreign matter (including lichens, moss, etc.) and saturated with a good quality preservative every few years. This cuts down on cracking and warping, which are, in large part, a function of the shingle drying out.
Preservatives are like moisturizer and keep your shingles looking youthful. Whatever you do, don’t pressure wash wooden shingles. This can severely damage them and also blows water through the complex of shingle and felt and can saturate the interior of the walls. If you feel a great need to clean, use a garden hose at a low force and a fiber broom. There are also medications available for this.
Thank you for loving your shingles. They love you back.
Best of luck,