Best way to stop boiler steam from entering attic
My old physics teacher would give you an 'A' for simply creating this question.

It is important to remember that whatever solution you choose must fix the problem, and not just move the problem to a different place - AKA: the Wack-A-Mole paradox.

I think the first step is to get an infrared thermometer,I chose this one,but pick your own vendor and price point

http://www.amazon.com/Etekcity-Lasergrip-Digital-Infrared-Thermometer/dp/B00DMI632G/

This will allow you to identify the source of the heat leaks, and locate the problem areas.

After you know what problem you are trying to fix, we can move forward from there.