A few things suggest themselves.
Are the loaves fully risen? An underrisen loaf will tend to be heavy
and soggy.
How long do you steam the loaves? I wouldn't suggest more than 10 to
20 percent of your bake time, and then I'd open the damper (if your
oven has one) to vent the steam.
Are you removing the loaves to a cooling rack? When bread is removed
from the oven it is still venting steam. If you put the loaves on an
impervious surface, some of the steam is trapped and it leads to a
soggy crust and crumb.
Was your oven at the right temperature? Many oven thermostats are
off. Using an oven thermometer to make sure your oven is at the right
temperature is a big help.
Did you bake your loaves all the way? Underbaked loaves will vent
more steam since the loaf is wetter inside than a fully baked loaf
would be. At sea level, I like to bake loaves of French style bread
until they have an interior temperature of around 205F, or 96C. One
advantage of using a thermometer is that it is repeatable. The time
honored "bake it until it sounds hollow when you tap the bottom of
the loaf" doesn't give you much control.
Hope that helps,
Mike
Mike Avery mavery at mail dot otherwhen dot com
part time baker http://www.sourdoughhome.com
wordsmith
A Randomly Selected Thought For The Day:
I haven't lost my mind; it's backed up on tape somewhere!