Aluminum/Concrete Footing Chemical Reaction 2

[bgpaddock]

I'm installing an aluminum fence in concrete postholes. The aluminum posts will be in direct contact with the concrete. My sixth sense tells me there may be an adverse reaction between the concrete and aluminum. Do I have valid reason for concern.

 

[SlideRuleEra]

You do, under certain conditions. See the the out-of-print "Nonferrous Metals in Contact With Concrete" on this page of my website

http://www.slideruleera.net/PCA-Page.html

http://www.SlideRuleEra.net

 

[boffintech]

Are you sure that this fence is aluminum? The reason I ask is that aluminum fencing is wildly expensive and mostly only used by the DOT (in our area at any rate).

 

[Ron]

bgpaddock....this is a common occurrence and yes, a reaction will occur if you do nothing to protect the aluminum.

One successful method to isolate the aluminum is to dip the posts in clear urethane coating. Allow it to dry, then embed the post in concrete. This will last for many years without problems.

You may also dip or coat the post with asphaltic material; however, the heavy bodied asphalt coating actually creates a space between the aluminum and concrete that can cause the post to loosen with time.