Firefighters have been hearing the rumblings of the dangers of manufactured I-joists, also called plywood I-beams for some time now. Click here for an EXCELLENT link to a video demonstrating the dangers of this new type of construction and why they're killing firefighters.

Construction companies will tell you a manufactured I-joist is stronger than 2x10 and 2x12 joists, which is initially true, until the plywood web between the manufactured joist starts to weaken under flame and heat impingement.  At that point they are weaker and subject to catastrophic failure. Please take the 5 minutes to watch THIS VIDEO. Think it doesn't affect you? You could be dead wrong. You can click the picture for the video link.