An Insidious Leak

Some roof leaks are harder to find than others. But leaks in the field of slate, away from flashings, or other obstacles, where there are no visible signs of a broken or missing slate are almost always caused by a failed or rusted bib.

Rusted sheet metal bib with nail head sized hole.

The potential for the bib to fail is one of the two flaws in the "nail and bib" method of slate roof repair. The other significant flaw is that when nailing the slate in place, the two slates where the nail is driven is, are invariably damaged. 

Damaged slates from a nail and bib repair. (not to mention source of leak)

On the other hand, a slate repair using a slate hook will never fail. Of course, one can't use a slate hook in every situation, but where it can be used, it should be used. I once heard of another contractor say he didn't use slate hooks because they "stain" the roof, yet he had no problem install big, galvanized #100 snow guards that certainly left a much greater impact. 

A galvanized slate hook. 

But I still don't buy that theory. Slate hooks leave very little visual impact on the roof, especially galvanized hooks. Some like to use the stainless steel version, but I find them jarring on a sunny day. 

Zoomed in on a slate hook on a sunny day. 

The photo above is a zoomed in picture of a galvanized slate hook. Kind of hard to see, and given the location of a hook - in the keyway, any run off staining is virtually non existent -- unless it is the zinc killing off roof mold, and then only slightly. 

That leak where no slate are visibly broken is likely an old slate repair. If no slate repair can be found, there could be another cause -- read about it here. 

The Exotic Tastes of Squirrels

I've never considered squirrels the smartest of natures creatures. They can never seam to remember where they've left their nuts!  These furry little rodents have something in common with the ancient Romans. Mainly, they enjoy the taste of lead. As the picture below shows, a squirrel has been actively chewing on this lead vent collar, which is not an uncommon problem where one of these rodents has developed a sweet tooth. The ancient Roman sweetener known as sapa was manufactured by boiling un-fermented grape juice in lead vessels. The lead would leach out into the mixture, and ultimately form lead acetate. The volume of reduction determined the sauce, which was used to sweeten meats and vegetables and help preserve food. For a more thorough explanation of the ancient Roman and Greek sauces, click here. 

But back to the present, when this becomes a problem, the collar can be changed to copper, or if possible, the put a new lead sleeve over the top and relocate the squirrel by renting a trap and trapping the squirrel. How can you identify the problem squirrel? He's or she's the one wearing the toga. 

Think of What Will Happen Years After the Roof is on

Aimed at contractors of the early 1910's, these old slate advertisements from couldn't be more telling of things to come. "Think of what will happen years after the roof is on." Could the quarries of Bangor slate have imagined their products of 1916 would still be on roofs in the 21st Century? Believe it or not, there are still a few original Bangor roofs quarried in the teens on roofs today. 

Yet, in an even smaller advertisement promoting the "genuine Peach Bottom roofing slate," we sit in amazement that this product of the earth will survive on roofs far into the 21st Century. Chapman slate roofs continue to prove long lasting on many, many roofs, as well. 

What could be more historical and more eco friendly than a material that far outlasts nearly all other building materials?

Scam Alert

Scenario: A roofing salesman comes out and meets with a homeowner and proceeds to inspect the homeowner's roof. Using a modicum of fear as a selling tactic, the salesman, or if he does not have a sales license, he may refer to himself as "estimator," proceeds to explain that all of the flashings on the home need to be replaced, (whether they need it or not). Or the chimney needs X,Y or Z. While this scenario is a scam within itself, the full scam has yet to play its full self out.

Who is Trip Trapping Across My Roof?!?

Once, there was a slate roofer tapping and a tapping new slate into a roof. "Who is that trip trapping on my roof!" was heard from the ground!

Warning! NSFSR (Not safe for slate roofers)

People are totally unaware of what goes on thirty feet above their heads, yet I'm sure a check was written and cashed for the lousy workmanship shown below. For a very simple primer on how to correctly repair a slate roof, click here. 

Glacial Roof Snow Damages Slate

What we have here is a copper tab held in with a galvanized nail.

Uninspired Methods of Slate Repair

It seems as that if you ask five different slate roofers what is their method of slate repair, you'll get five different answers. Way back when our company started, the slate quarries recommended using hooks for slate repairs. The logic of their suggestion to use something so small, inexpensive and simple to hold a replacement slate onto an existing roof seemed to make sense and nothing I've seen since has surpassed the functionality and simplicity of the slate hook. Roofers have used other methods for replacing slate, but as some of the other methods are illustrated, it becomes clear they are needlessly destructive or complicated.

Surprise

One never knows what one will find living in the roof. I was surprised to see this little winter wren nesting in this Ludowici Imperial tile roof. The sun was in my eyes when I was photographing the roof, and there he was along with the nest after I downloaded the pictures. 

From time to time, I will be posting content about slate roofing best practices. I have inspected thousands of slate roofs over twenty-three years  and worked on slate while in college. Slate roofing is a craft, and I have seen a lot of great work and craftsmanship and met some good people along the way. But I've also encountered a lot of shoddy workmanship and I hope to explore the good and the bad. Information now abounds about slate roofing. There are many books, articles and a journal or two devoted to the craft and maybe we can highlight a few of those, too.