I have been interested in the communications of your correspondent in regard to shingles. I have had over thirty years’ experience in building and repairing roofs. I have taken rifted pine shingles from off several roofs that were worn entirely through, at the line where the water falls from one shingle upon the next one below, while underneath the courses the shingles were as bright as when first laid.
Such is not the fact with sawed and cut shingles, from any kind of timber. The reason is, that sawed and cut shingles are cross-grained, so that water runs through the pores of the wood,—wets the under course, and, in wet seasons, seldom if ever dries.
The agents of decay are, air, water and heat. All are combined on a roof to produce decay, and you have the effect on all roofs made of sawed or cut shingles. I have replaced many roofs of sawed shingles, but they never were half worn; they were rotten and unfit to remain longer.
Let any one examine a sawed shingle, and he will find the grain severed and every pore, through which the sap was pumped up from the roots to the branches, is a water-pipe to conduct water through the shingle, instead of over it, as is done by a rifted shingle.
I advise every man, who has means to procure a rifted and shaved shingle, never to use a sawed or cut one. I think slate is the most economical and durable of all roofs. Tin will do well, and roofs with it will be laid more flat, thereby making less surface to cover. There may be compositions that will make good roofs, but I know of none I would accept as a gift, and I have tried several kinds. In choosing rifted shingles, don’t get those of twisted grain, so that one side will turn up and the other turn down.
Any person who will discover a cheap kind of roofing, that will endure our variable climate, will deserve the everlasting gratitude of his kind. But forever deliver me from sawed, and more especially cut shingles.
Correspondent—Boston Cultivator
The Canada Farmer – June 1, 1864
—Jeff Burks
A Shingle sawing and packing operation at a small mill near Jefferson, Texas 1939.
Interesting comments about shingles. Let’s fine tune the concept of why wood rots…the article says 3 things are needed – air, water and heat. The reality, perhaps self evident, is you also need a food source., i.e. the shingles. We control rot by eliminating one of the four rot requirements; now-a-days we poison the food source with CCA or some other chemical combination often containing copper. It is very difficult to control the other three.
What the 1864 dialog did not understand is that sunlight ‘s UV destroys the lignin that holds the wood’s cell structure together. Once the cell structure breaks down, the cellulose washes away, and over time the butt end of the exposed shingle gets thinner and thinner.
Riven shingles, by definition follow the wood’s grain, however the choice of wood species will play a major roll in the health of a roof. Even Roubo comments on the rot resistance of cedar, and this is why cedar as a “food” source on a roof is so useful,,,it is toxic to fungus.
Copper on a roof, say in a strip up under the ridge cap, with a half inch of copper exposed will allow copper to wash down the roof and poison fungus. Carefully placed copper strips, barely visible from the ground, can ensure rot and other biota are kept at a minimum over the years. Do this along with proper spacing between shingle’s sides so they don’t buckle and you are good to go…and never “staple”wood shingles in place…the staples rust off and the the shingles blow away.
Richard O. Byrne
Staunton, VA
I completely agree with that old time correspondent — I’ve regularly seen the same thing. The rift and shaved shingles are far superior and I’ve seen them last 3-4 times longer than standard asphalt. It’s very labor intensive, historically appropriate, green and a great workout. For preservation work with the school we setup shave horses and had students split and shave down pine shingles for the Brookwood Barn reconstruction. If I recall we made something like 12,000 shingles for that 21’x21′ barn — so it was nice to have a good sized group of folks working together. You can see some of it in the slideshow at the end of this post:
http://rainfordrestorations.wordpress.com/2012/05/21/2-bay-english-style-barn-raising-at-brookwood-farm/
Wow – the photos of the guys working around that saw blade made me cringe. And I thought my table saw was dangerous.
Cedar shake shingles used to be used here in California, and you can still find them here and there. But less so over time, as they are now banned due to the fire potential in our semi-arid desert environment.
Mark Singleton
Santa Maria, Ca
We regularly use cedar and even Cyprus when we can. Hand split shakes are by far the best choice, but are increasingly harder to get. Paired with ss nails and lead or copper flashing, and swept hips and you have one of the most beautiful and durable roofs out there. I have seen the copper strips to try to stop fungus, but seem to just stain everything below them with no real benefit.