"There's got to be a better way."In one respect, post Katrina construction failed before it even got started. In the rebuilding effort, all of the galvanized steel construction components such as joist hangers, hurricane straps and ties, reinforcing straps, and hanger rods used for suspending the plumbing between floors and beneath slabs are no better than they were before the hurricane struck.
How can we say this with such certainty? We can say this because within a few weeks after reconstruction began, brand new, galvanized construction components were observed to be rusting. Some were already pitted.
We can say this because, wherever there is oxygen and moisture, corrosion and rust will exist and thrive. When those two factors are combined with salt and corrosive elements in the air, sand and soil, the rate of corrosion increases. Throw in humidity - especially in regions where 50% humidity or higher increases the rate of corrosion exponentially - and it's safe to say that construction everywhere is failing.
Galvanizing and Stainless SteelA layer of zinc galvanizing is applied to much of the steel that will be exposed to the elements. Utility and traffic structures, and construction components and fasteners are usually galvanized. That layer of galvanizing is called a "sacrificial" coating. It takes upon itself the damage that is caused by corrosive elements in the air, water, and soil, thereby protecting the steel underneath. The photos on this page show what happens once the galvanizing has reached its sacrificial capacity
When two dissimilar metals are in close proximity to one another, galvanic corrosion occurs. This can even happen with stainless steel. The band clamp pictured here is composed of two different grades of stainless steel. One corroded the other and eventually destroyed the clamp.