Hi all:

My house is about 15 years old. The center of the house has a
cathedral ceiling two stories high. On either side of this area, the
ceilings are standard 8'. The vertical wall separating the attic
above these spaces from the room with a cathedral ceiling is insulated
with what appears to be R-19 fiberglass batts. The walls are studded
with 2x4's, which leaves some of the insulation protruding on the
attic side of the walls. The builder used clear polyethylene plastic,
stapled to the studs, to hold the batts in place. After 15 years of
attic heat (I live in South Carolina), the plastic has begun to
literally fall apart. Very little of the insulation has shifted, but
I am concerned that it will. I can see the paper vapor barrier
against the back side of the drywall, as is typical in my climate.
Presumably, the paper is stapled to the studs on the drywall side, but
I can't tell for sure. Even if it is, there are a couple of places
where the insulation is separating from the paper, so I need to find a
way to support the insulation.

I want to replace the plastic, but I am concerned that if I use
plastic sheeting, it will become a second vapor barrier, which I
understand is undesirable. Also, I don't want to be doing this again
in another 15 years. I found some plastic anti-bird netting at a
local home center that is supposed to be UV stable. It's essentially
a 5/8" square mesh made from plastic. I thought about stapling this
over the insulation to hold it in place, but I wonder how long it will
last. I guess I could use metal chicken wire (poultry mesh, if you're
PC), but wouldn't that interfere with radio and cell phone signals?
Do they make a product specifically for this application? If so, what
is it called? Any other ideas?

Thanks in advance,
John.

the_tool_man wrote:
....
a 5/8" square mesh made from plastic. I thought about stapling this
over the insulation to hold it in place, but I wonder how long it will
last. I guess I could use metal chicken wire (poultry mesh, if you're
PC), but wouldn't that interfere with radio and cell phone signals?
....

Either will work fine--I'd expect the plastic mesh, particularly if it
is fiber-reinforced, to last quite a while. The wire would, of course
be permanent.

It won't be significant for RF attenuation owing to the porosity.

I'd think a simpler and probably cheaper solution would be to simply use
some light wire on about 18-24" centers stretched across, however. I
don't think you need anything near a full areal coverage to do the job
adequately although it would, of course be certain.

--

On Nov 13, 10:16*am, dpb wrote:

I'd think a simpler and probably cheaper solution would be to simply use
some light wire on about 18-24" centers stretched across, however. *I
don't think you need anything near a full areal coverage to do the job
adequately although it would, of course be certain.

--

Possibly, but since the insulation protrudes from the studs by about 2
inches, I would think a mesh solution would work better without
compressing it very much. Wire might kink it enough to reduce its
efficiency. I'm headed to the store now to get a look at the anti-
bird mesh. I'll report back with what I find.

Regards,
John.

On Nov 13, 6:55*am, the_tool_man wrote:
Hi all:

My house is about 15 years old. *The center of the house has a
cathedral ceiling two stories high. *On either side of this area, the
ceilings are standard 8'. *The vertical wall separating the attic
above these spaces from the room with a cathedral ceiling is insulated
with what appears to be R-19 fiberglass batts. *The walls are studded
with 2x4's, which leaves some of the insulation protruding on the
attic side of the walls. *The builder used clear polyethylene plastic,
stapled to the studs, to hold the batts in place. *After 15 years of
attic heat (I live in South Carolina), the plastic has begun to
literally fall apart. *Very little of the insulation has shifted, but
I am concerned that it will. *I can see the paper vapor barrier
against the back side of the drywall, as is typical in my climate.
Presumably, the paper is stapled to the studs on the drywall side, but
I can't tell for sure. *Even if it is, there are a couple of places
where the insulation is separating from the paper, so I need to find a
way to support the insulation.

I want to replace the plastic, but I am concerned that if I use
plastic sheeting, it will become a second vapor barrier, which I
understand is undesirable. *Also, I don't want to be doing this again
in another 15 years. *I found some plastic anti-bird netting at a
local home center that is supposed to be UV stable. *It's essentially
a 5/8" square mesh made from plastic. *I thought about stapling this
over the insulation to hold it in place, but I wonder how long it will
last. *I guess I could use metal chicken wire (poultry mesh, if you're
PC), but wouldn't that interfere with radio and cell phone signals?
Do they make a product specifically for this application? *If so, what
is it called? *Any other ideas?

Thanks in advance,
John.

John-

imo the fastest, cheapest, easiest & longest lasting would be "stucco
line wire" (similar to DPB's suggestion)

I'd start a few inches down from the top & nail in a row of dry wall
nails across the wall studs......repeat the process about even foot or
so....ending with row, again, a few inches from the bottom.

After all the nails are in starting from the upper left (if your right
handed) wrap the wire around the first nail. Continue across the
studs, givining the wire a wrap or two at each nail.

At the far end, don't cut the wire, just jump down to the next row of
nails. If you're concerned about wire breakage (in the future or
want the make the wire runs more independent...nail down end of row
nails once the wire is wrapped around them.

This will be super fast, never need to be redone & cheap.

I don't remember the diameter of line wire (like 18 or 20
gage ?) ......something like 1/32"? but anything you can buy cheap
in the .030" to .040".

The stuff is dead soft & easy to work with.

cheers
Bob

the_tool_man wrote:
On Nov 13, 10:16 am, dpb wrote:
I'd think a simpler and probably cheaper solution would be to simply use
some light wire on about 18-24" centers stretched across, however. I
don't think you need anything near a full areal coverage to do the job
adequately although it would, of course be certain.

--

Possibly, but since the insulation protrudes from the studs by about 2
inches, I would think a mesh solution would work better without
compressing it very much. Wire might kink it enough to reduce its
efficiency. I'm headed to the store now to get a look at the anti-
bird mesh. I'll report back with what I find.
....

I don't think it would be a problem--any compression is pretty localized
and wouldn't have to string the wire tightly, anyway (in fact, wouldn't
want to).

But, another thought -- take either the netting or the chicken wire and
cut it into narrower strips -- it'll have sufficient surface area but be
less costly.

--

BobK207 wrote:
....

imo the fastest, cheapest, easiest & longest lasting would be "stucco
line wire" (similar to DPB's suggestion)

I'd start a few inches down from the top & nail in a row of dry wall
nails across the wall studs......repeat the process about even foot or
so....ending with row, again, a few inches from the bottom.

After all the nails are in starting from the upper left (if your right
handed) wrap the wire around the first nail. Continue across the
studs, givining the wire a wrap or two at each nail.

....

That works and similar to my thoughts, certainly. Since it's a vertical
wall (I think?), my thought would be to start at upperleft (say) and go
diagonally across to opposite corner or at 45 or less angle depending on
the wall length -- that gives a longer area across each wall cavity the
wire runs.

I'd also probably use only the two end nails initially (although they
would have to be heavier to hold the load) then stretch it not very
tight (just enough so it doesn't sag much) and then use a stapler w/
decent-sized staple to fasten down the middle. That saves the wrapping
around the nails in the intermediate runs which saves both time and
(some) wire...

--

On Nov 13, 1:22*pm, dpb wrote:

I don't think it would be a problem--any compression is pretty localized
and wouldn't have to string the wire tightly, anyway (in fact, wouldn't
want to).

But, another thought -- take either the netting or the chicken wire and
cut it into narrower strips -- it'll have sufficient surface area but be
less costly.

--

I went ahead and bought a roll of the anti-bird mesh. It appears to
be a grid of plastic fibers that are melted or bonded together where
they intersect. I attempted to rip it apart with my hands, and
couldn't, so it's pretty strong. For about $20, I got a roll that is
14' x 45'. If I cut it into 1' wide strips, and space them apart,
it's more than enough to do the whole house. Thanks for the
suggestions.

Regards,
John.