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Galen Boyer
 
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Default Blow-in Insullation, How?

On Mon, 27 Mar 2006, wrote:
Galen Boyer wrote:


I'm dreading it, but I think I'm laying down fiberglass after
taking up
the first layer. Ughh!!!
Thanks.


Wow. You may need to take up the first layer, but before you do
that think about what you have. You didn't mentioned the age of
the house


It was built in 1860.

or how it is built.


Plaster cieling. Some sections have a layer of dry-wall over them.

Is this an old house? If so, is the ceiling well sealed with oil
paint?


I'm not sure how to tell if oil paint was ever used.

If you answer yes to either of those, the several layers of paint
probably constitute a moisture barrier. If so, you don't need to
remove the first layers.

Even if the ceiling paints are not oil,if you have plenty of
ventilation in the attic you can get by with no moisture barrier.
The whole point of the moisture barrier is to keep the insulation
dry and with adequate ventilation it will stay dry even if
moisture rises through the ceiling materials.


It doesn't look like there has been an issue with moisture before (I'm
looking for mold when I say this), but I don't have a clue as to how old
the current insulation is. If it isn't too old, then signs of moisture
might not show? My guess is that the current insulation is at least a
decade old and probably way more than that.

If you decide you need a moisture barrier consider placing 3 mil
plastic down (over the joists with plenty of slack between
joists, and replace the original first layer materials filling
the cavities to the top of the joists. Consider adding back some
(unburned) boards across the joists to make moving around easier;
I would put a screw in each end and into the joists so the board
doesn't move.


The reason I'm hesitant to put down boards and screw them in is that I'm
then going to lay a second layer. I just have some big boards, about 2
ft by 3 ft and 2 inches thick and I just move those around so I can
maneuver the attic.

The rest is more or less correct, i.e., lay unfaced fiberglass
batts crosswise to the joists. There is no need to throw away any
of your insulation materials.


Hm... Oh well. I just wanted to be able to see what I had in the first
place. The second layer was not laid down with any sense of organization
and boards were surfacing as I removed the second layer, and

Don't forget to provide adequate ventilation in the attic.


Yeppers.

--
Galen Boyer