My wife and I moved into our home a couple of months ago. In the process of installing insulation in the attic I discovered that although the previous owners had installed an exhaust fan for the bathroom, they did not vent it outside, so it has just been sucking humid air up into the attic. Fortunately we are in an old DC rowhouse and the bathroom has an awesome sunlight/vent, so we've just stopped using the fan, but I'd like to correct this problem.

I've never done any roofing work before and am nervous because our house has a flat roof. Can anyone suggest the proper type of vent hood to use in this application and help me with some directions for how to avoid a leaky roof?

Thanks!

If at all possible, avoid going through a flat roof. It's to hard to seal and keep sealed. If you have an attic space you should have a wall above the ceiling that you could go through.