Slate Roof - History of Roofing

Can a Roof last 100 years?

Slate Roofs are one of the longest-lasting roofs you could have and are found all over the world. It is not uncommon to see these stone-like roofs last 100-200 years. I recently took this photo from Scotland. These beautifully aged roofs can be found on a king's castles or even a simple country cottage. Slate roofs are made from large slabs of rocks called shale. These shale quarries can be found all over the world. The shale was formed from compressed sediment that would, over many years become a mudstone. This compression of the different sediment would create grains, that are called cleavage planes. After the stone has been taken from the quarry it is cut and sized then split by a craftsman to make the slate roofing materials. Every slate is different because it is hand split and because of the different colors of the sediment.

The different types of colors available are amazing and my favorite is many colors of reds and blues blended and I like the roofs installed with slight changes thicknesses and slate exposure. Above is a rarely seen slate roof in Sacramento CA with a canoe valley weaved. The slate is installed by nails. The slater, if not done yet would knock two small holes into the slate where needed and fasten the slate with copper nails to a skip sheathing board. The use of these long-lasting stone shingles normally has copper flashings because of its rust-resistant properties lasting as long as the slate.

Having personally been in the roofing business long enough to enjoy re-roofing some of my own roofs that met their life cycle. I could not imagine slaters having to wait over a hundred years to re-roof one of his slate roofs.

It has been said the slaters would commonly nail a small lead plate to the sheathing and then cover it with roofing. It would have been formed or carved with one’s initials, tools used, a date, or some design they wanted, leaving it as a little time capsule to be discovered years later by the next roofer. These little lead memories are nice to find. I have two of them under glass hanging on my office wall. Slate roofs are not just an average 3 tab roofing system.

They are works of art and crafted by old school methods of roofing known only by a few roofers here in the states, mostly by craftsmen in the northeastern parts of America.

The copper etching says, "In the Netherlands when a Dutchman did a slate roof, he built it to last and he knew it would for over a century or more. These lead plates were found when re-roofing 100-200-year-old roofs. Notice the initials and tool of the trade carved on these two plates."

Have a question? AskARoofer HERE 

Need a contractor?  Check out our list of Roofing Contractors HERE.