Lead Flashing: Is It Dangerous?

 The Pros And Cons Of Lead Flashing

Lead Flashing: The Green Approach To Flashing Your Chimney

We often get a quizzical look when we discuss the use of lead flashing in our chimney repairs, and we'd love to answer your questions about the safety and efficacy of using lead flashing in chimney repairs.

The following are quotes from the ELSIA, the European Lead Sheet Industry Association's brochure on lead sheets primarily used in capping or flashing for rooftops:

1. "There are many historic monuments throughout Europe, some of them more than 500 years old, which are still protected from the ravages of nature by original lead sheets." 
2.  "Lead can be endlessly recycled, leading to a metal recovery rate in excess of 95% with no loss of properties or potential end uses." 
3.  "The European Lead Sheet Industry Association (ELSIA) has made considerable investments in independent research. Lead sheet poses no risk to the environment, even when water run-off is taken into account, and does not present any risk to human beings. Furthermore, providing simple hygienic precautions are observed, such as rigorous hand-washing, people who handle significant quantities of lead do not expose themselves to health risks."
4. "Another notion is that lead is damaging to the environment, particularly old lead sheet from which rainwater may carry particles to the ground. TNO in the Netherlands was engaged to investigate atmospheric corrosion of lead sheet and any environmental impact it may have. After a year long study, it was concluded that exposure to the atmosphere causes lead sheet to react rapidly to form a tightly adherent, stable patina of virtually insoluble lead compounds. The concentration of lead in rainwater run-off was found to be less than previously thought and has no public health or environmental impact."

You can read the brochure yourself at:
ELSIA Lead Sheet Brochure

But what does this actually mean for Americans?
We're often skeptical of overseas documentation about carcinogens, and whether it actually stands up to American values.

• What I found out during my exhaustive search for "Lead Flashing Runoff", is that most of the runoff from roofs actually involves very high rates of...Zinc!

The actual villain in most roofs today is Zinc, the stuff that coats nails, low-cost flashing, and gutters. What does this Zinc do? If the levels are high enough, the Zinc will actually kill aquatic life. That means that it will effectively kill good bacteria, small plant life, and the fish that feed off it.
You've heard of toxic algae blooms in the creeks and rivers on Long Island - this is due to storm water runoff that includes septic system runoff, pesticides, and yes, the Zinc that runs off your roof.

So what about Lead? Little bits and pieces involving studies in Paris (where lead is everywhere on roofs, I mean entire roofs made of lead - are out there, but nothing on putting a small sheet of lead around your chimney. I tracked down a couple of articles that repeated what the ELSIA brochure said:

1. Lead, when exposed to the elements, gets a sort of "patina" on it (similar to copper) and this patina effectively holds in lead, keeping any contamination to an absolute minimum. 
2. Lead needs to be looked after occasionally. Simply said, in 20 or so years, you're going to want to have someone take a quick look at it to make sure that it's not cracking or flaking. Guess what? In most environments, lead won't crack for oh, 50-100 years. Okay, 'nuff said on that. 

But! Being a the curious guy that I am, I decided to get in touch with the local Baykeeper, and ask him his experience with the matter: (I'm still waiting for a callback on that, so see a future blog for info).

In absence of his advice, I went to the authority on it: The DEA.
There I found a brochure on the Long Island Sound, and something called "Non-point" pollution. Basically, non-point pollution is the stuff that's harder to track than just your average pipe with sewage coming out of it. It's the stuff that comes from the air, or other untraceable stuff.

1. "The major source of lead found in Long Island Sound is urban runoff. Fortunately, as a result of the switch to unleaded gasoline, this input is decreasing."
2. "Airborne pollutants such as sulfur, lead, and nitrogen - emitted from car exhaust pipes and building smokestacks - attach or adsorb moisture and particles in the atmosphere. When enough moisture is present in the air, it rains or snows, carrying these pollutants back to the land and water."

You can see it here: The DEA's Long Island Sound Study

What can we do about this? 

Well, from what I read, not using lead in areas where the storm water has no where to go except into the sewer  is one way to go about it. Since our company only does residential work, that's not a concern for you. 

Plant a tree. Yes, it's as simple as that. Make sure that the water that comes from your gutters a actually goes somewhere (like into your lawn) instead of into the sewer - plants and trees hold the water in the soil and keep bad stuff out of our bays and waterways. 

What about collecting water for gardens?

See these articles - they're where I found about about the Zinc problem. 

http://www.stormwatercenter.net/Library/Practice/8.pdf
http://tylertork.com/diyrainbarrels/safety.html

To sum up all of my research: I've found out that Lead can be a very friendly metal. It's environmentally correct, in that one repair will last up to 500 years, it can be recycled easily, and it doesn't contribute to a significant amount in storm-water runoff if managed by adding plants and trees to your yard. How cool is that? I'm happy to be a part of the solution - not using Zinc and Zinc-plated aluminum in flashing chimneys should be a #1 priority on every roofer's list.