How do I prevent my gable vents from clogging with ice?
I have to wonder if the bathroom vent is really "fine" or if it's failed in some manner so that it vents out of the bathroom, into the attic (rather than out of the bathroom, through the attic and out of the wall) - that would certainly add a lot of water vapor to the attic...which would be one way to clog up the vents.