Wrong Attic Insulation

You've heard the old saying,"
Sometimes, something is better than nothing." Well, I would imagine this
saying applies in a situation like this. It would always be better to
have some attic insulation instead of no attic insulation.
You can clearly see the number three on the attic insulation. This
represents the thickness of this particular type of insulation. Usually 3 inch insulation would be used for 3 1/2 inch
wide walls and not in an attic, were you have plenty of room to install
thicker insulation.
Using the wrong type of attic insulation isn't going to create a big
problem for your home. However, the thicker the attic insulation
actually is, the more effective that it will be in controlling the heat
and cooling loss from the home.
Home Repair Tip: You can leave the existing three-inch attic insulation
in a case like this and add additional insulation to it. Just make sure that you use an un faced insulation
otherwise you could have a moisture problem between the two moisture
barriers.
In other words only purchased insulation that doesn't have any paper or
other type of barrier attached to the insulation itself. The insulation
that you're going to be installing in a situation like this won't have
anything attached to it.
I would recommend installing the sickest attic insulation that you can
possibly afford. Eventually you will get a return on your investment as
your heating and cooling costs start to minimize.