== I-joists == 

 You uploaded a photo from Flickr of I-joists, but the photo is not of I-joists, and the description is vastly different from the one on Flickr. They are old solid timber joists which have sustained fire damage, not engineered lumber. 

 Any idea where the wires got crossed? Were you expecting the upload to be of a different photo? If so, any chance that you might root it out?