Angle Iron Retrofits-Will they work?

Angle Iron Retrofits.

Here you can see an engineering analysis and opinions of the structural engineering community regarding the effectiveness of angle irons.

Angle Iron Braces

This video discusses an untested retrofit method that your contractor or engineer may recommend.  It is a general standard of practice that only tested retrofit hardware and methods should be used.  Otherwise, what will happen is anyone’s guess.

The information in this video was created after consultations with numerous structural engineers, especially Bay Area based Thor Matteson, and Josh Kardon Ph.D.  Both of these structural engineers told me they would be happy to tell people about them if you want to call them.

Kelly Cobeen was kind enough to do actual calculations regarding their effectiveness.  In conclusion she discovered that an Angle Iron Brace has the strength of 1/4 a bolt.  Numerous structural engineers were kind enough to answer questions I had about their efficacy.  In addition, Buddy Showalter with the American Wood Council, the largest wood products research center in the world, was willing to give his expert opinion.  All these engineers are highly distinguished in field of wood-frame seismic retrofitting.

In sprite of their likely ineffectiveness nevertheless very expensive, as shown in this 2017 estimate from a local contractor.

$2,120.00 quote to install angle iron braces

 

Sample Angle Iron Braces used Extensively in San Francisco Bay Area seismic retrofits

 

Image of angle iron braces from contractor website

Photograph of angle iron installed under house

 

 

Angle iron brace on engineer's plansDiagram from engineer's plans showing angle iron braceHere are some angle iron brace construction details drawn by a local retrofit engineer

To the left the red arrows are pointing at locations for the angle braces.  To the right is the construction detail telling the contractor how to install the Angle Iron Brace.

In conclusion: just because you hired an engineer does not mean your retrofit will be done right.

 

 

 

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