[Joe]

My outside walls felt cold this past winter and I wanted to check if
they were insulated. Outside of knocking a hole in the wall is there
any better way of managing the destruction to see inside the walls? If
I put the hole low to the floor will I be able to see insulation or
does it generally start further up and how big of a how is necessary?

[Pete C.]

Joe wrote:

My outside walls felt cold this past winter and I wanted to check if
they were insulated. Outside of knocking a hole in the wall is there
any better way of managing the destruction to see inside the walls? If
I put the hole low to the floor will I be able to see insulation or
does it generally start further up and how big of a how is necessary?

I don't know of any magic solution, and what you observe in one wall
cavity may not be representative of any other wall cavity. That said, I
think the least intrusive method is to remove the cover plate from an
outlet or switch box and try to peer past the edge of the box. You can
carefully widen the gap with a utility knife to get a better view if you
want and can always get an oversized cover plate to cover the widened
opening if necessary.

[Tony Sivori]

Joe wrote:

My outside walls felt cold this past winter and I wanted to check if they
were insulated. Outside of knocking a hole in the wall is there any better
way of managing the destruction to see inside the walls? If I put the hole
low to the floor will I be able to see insulation or does it generally
start further up and how big of a how is necessary?

If the homes nearby are of similar construction, ask your neighbors.

--
Tony Sivori

[jmagerl]

In my totally uninsulated house, the wall temp ran about 20 degree cooler
than the air temp during the winter.



"Pete C." wrote in message
...
Joe wrote:

My outside walls felt cold this past winter and I wanted to check if
they were insulated. Outside of knocking a hole in the wall is there
any better way of managing the destruction to see inside the walls? If
I put the hole low to the floor will I be able to see insulation or
does it generally start further up and how big of a how is necessary?

I don't know of any magic solution, and what you observe in one wall
cavity may not be representative of any other wall cavity. That said, I
think the least intrusive method is to remove the cover plate from an
outlet or switch box and try to peer past the edge of the box. You can
carefully widen the gap with a utility knife to get a better view if you
want and can always get an oversized cover plate to cover the widened
opening if necessary.

[Bob F]

"Joe" wrote in message
oups.com...
My outside walls felt cold this past winter and I wanted to check if
they were insulated. Outside of knocking a hole in the wall is there
any better way of managing the destruction to see inside the walls? If
I put the hole low to the floor will I be able to see insulation or
does it generally start further up and how big of a how is necessary?


How hot are the inside walls when the sun is on the outside of the same area?

How old is the house?

Remove outlet plates on outside walls, and look for insulation outside the box.

Bob

[Banty]

In article .com, Joe says...

My outside walls felt cold this past winter and I wanted to check if
they were insulated. Outside of knocking a hole in the wall is there
any better way of managing the destruction to see inside the walls? If
I put the hole low to the floor will I be able to see insulation or
does it generally start further up and how big of a how is necessary?


Call your local electric company and ask for an energy audit. One step of that
is that they'll use an infraread camera, and if the walls are uninsulated, the
studs will stand right out as very dark against a bright background. The tech
will have the experience to know if the walls are uninsulated or not.

It's a good idea for many other reasons, if your house is older construction.

Banty

[Joe]

On Jul 27, 12:45 pm, "Bob F" wrote:

How hot are the inside walls when the sun is on the outside of the same area?


relatively cool, but I checked the walls on the inside of the
uninsulated garage and the inside wall was barely warm. so maybe the
heat wouldn't transfer all the way to the inside wall.

How old is the house?

54 years old


Remove outlet plates on outside walls, and look for insulation outside the box.

only one oulet gives me enough room to see outside the box. I see an
empty area but I also saw something shiny like tin foil.

[Colbyt]

"Joe" wrote in message
oups.com...
My outside walls felt cold this past winter and I wanted to check if
they were insulated. Outside of knocking a hole in the wall is there
any better way of managing the destruction to see inside the walls? If
I put the hole low to the floor will I be able to see insulation or
does it generally start further up and how big of a how is necessary?


Turn off the electric to the cover plate you are about to remove.
Bend a straight piece of wire to form a small hook on the end.
Insert the wire beside the electric box and angle to the side.
Twist and pull. Insulation will be caught in the hook if you have any.
Repeat as many times as desired.

Note: that in most cases there is a stud on one side of the box and not the
other.

Colbyt

[Bob F]

"Joe" wrote in message
oups.com...
On Jul 27, 12:45 pm, "Bob F" wrote:

How hot are the inside walls when the sun is on the outside of the same area?


relatively cool, but I checked the walls on the inside of the
uninsulated garage and the inside wall was barely warm. so maybe the
heat wouldn't transfer all the way to the inside wall.

How old is the house?

54 years old


Remove outlet plates on outside walls, and look for insulation outside the
box.

only one oulet gives me enough room to see outside the box. I see an
empty area but I also saw something shiny like tin foil.


The foil suggests the possibility of insulation. The age suggests no insulation

The wire probe and the energy audit suggested by others would both be good
ideas.

Bob

[aemeijers]

"Bob F" wrote in message
. ..

"Joe" wrote in message
oups.com...
On Jul 27, 12:45 pm, "Bob F" wrote:

How hot are the inside walls when the sun is on the outside of the same
area?


relatively cool, but I checked the walls on the inside of the
uninsulated garage and the inside wall was barely warm. so maybe the
heat wouldn't transfer all the way to the inside wall.

How old is the house?

54 years old


Remove outlet plates on outside walls, and look for insulation outside
the box.

only one oulet gives me enough room to see outside the box. I see an
empty area but I also saw something shiny like tin foil.


The foil suggests the possibility of insulation. The age suggests no
insulation

The wire probe and the energy audit suggested by others would both be good
ideas.

You can buy oversize outlet covers, and enlarge the crack around the outlet
box. Seeing foil is actually a bad sign, since the only shiny insulation in
that era would be Z-fold foil. Kinda sorta a combination vapor barrier and
IR reflective layer. It helped a little, but not much. I'd budget to have
the walls blown. If outside is sided, they can pull 2 strips of siding, one
high and one low, and do it that way. (Don't let them do it through the
siding and use those damn snap-caps- even if the paint holds, they stick out
like sore thumbs.) If house needs resided anyway, they can blow, plus add a
layer of foam under the siding. If outside is brick, you are looking at
doing it from interior, and doing a lot of drywall patching, unless you like
the crown mold and tall baseboard look.

If there is a company with a thermal camera in your town, have them come out
first cool day, and they can tell you in five minutes what walls and roof
areas are insualated enough to notice. I wanted it done here, but no local
company offers it.

aem sends...

[Bob M.]

"Banty" wrote in message
...
In article .com, Joe
says...

My outside walls felt cold this past winter and I wanted to check if
they were insulated. Outside of knocking a hole in the wall is there
any better way of managing the destruction to see inside the walls? If
I put the hole low to the floor will I be able to see insulation or
does it generally start further up and how big of a how is necessary?


Call your local electric company and ask for an energy audit. One step of
that
is that they'll use an infraread camera, and if the walls are uninsulated,
the
studs will stand right out as very dark against a bright background. The
tech
will have the experience to know if the walls are uninsulated or not.

It's a good idea for many other reasons, if your house is older
construction.

Banty


Our local co. will only do an energy audit on a house once per lifetime of
the house!

[Kitep]

"Joe" wrote in message
oups.com...
My outside walls felt cold this past winter and I wanted to check if
they were insulated.

If there's adequate insulation, an exterior wall shouldn't feel much colder
than an interior wall. So unless your house was also cold, I'm guessing you
don't have much insulation. But as someone else suggested, get somebody
with an infrared camera and you'll know better.

Also, in some houses the wall cavities extend into the basement and aren't
covered. A look down there may tell you what you want to know.

[Joe]

who do I call to get the house blown? Do you mean the guys who blow
wet newspaper into the walls? Do all insulation experts do this or is
there a separate name for this procedure? Is this process better than
fiberglass?

[mm]

On Fri, 27 Jul 2007 22:22:20 GMT, "aemeijers"
wrote:



If there is a company with a thermal camera in your town, have them come out

Would it work to just buy infrared film for a standard 35 mm camera?
A good camera has a separate red dot on the lens to show where to set
the focus for infrared.

Would a non-contact thermometer be of any value?

first cool day, and they can tell you in five minutes what walls and roof
areas are insualated enough to notice. I wanted it done here, but no local
company offers it.

aem sends...

[[email protected]]

mm wrote:

Would a non-contact thermometer be of any value?

Sure. With 70 F house air and Tw and Ta wall and outdoor temps and
a slow-moving R0.67 indoor wall airfilm resistance and an Rv wall
R-value, we have this, viewed in a fixed font:

Tw
R0.67 | Rv
70 F ---www-------www--- Ta
------------
I = (70-Ta)/(Rv+0.67)

Tw = Ta+IRv, makes Rv = 0.67(Tw-Ta)/(70-Tw).

For instance, if you measure a Tw = 67.5 F wall temp with your $50 Raytek
MiniTemp when it's Ta = 30 F outdoors, Rv = 0.67(67.5-30)/(70-67.5) = R10.
This works for windows too. It's best done before dawn, when the outdoor
temp is changing slowly.

Nick

[Larry Weil]

In article ,
mm wrote:


Would it work to just buy infrared film for a standard 35 mm camera?
A good camera has a separate red dot on the lens to show where to set
the focus for infrared.

You would also have to buy a filter for the camera so only infrared gets
in. Infrared film also responds to visible light, so the filter is
necessary.

The other problem may be finding someplace that can properly process
infrared film, my guess is that Walmart and the local drug store would
have no idea what to do with the stuff.

--
Larry Weil
Lake Wobegone, NH

[[email protected]]

mm wrote:

Would it work to just buy infrared film for a standard 35 mm camera?

That kind of film won't show warm vs hot spots, and if it did, the heat
in the camera would expose it, unless the camera were cooled.

With 70 F house air and Tw and Ta wall and outdoor temps and a slow-moving
R0.67 indoor wall airfilm resistance and an Rv wall R-value, we have this,
viewed in a fixed font:

Tw
R0.67 | Rv
70 F ---www-------www--- Ta
------------
I = (70-Ta)/(Rv+0.67)

Tw = Ta+IRv, makes Rv = 0.67(Tw-Ta)/(70-Tw).

For instance, if you measure a Tw = 67.5 F wall temp with your $50 Raytek
MiniTemp when it's Ta = 30 F outdoors, Rv = 0.67(67.5-30)/(70-67.5) = R10.

It's hard to measure an R30 wall this way, because the indoor wall temp
is very close to the indoor air temp (69.1 F). Aiming the IR thermometer
into a 1" hole in 1 ft^2 of 2" R10 Styrofoam pressed against the wall for
a few minutes could increase accuracy, making something like this:

Tw
R10.67 | Rv
70 F ---www-------www--- Ta
------------
I = (70-Ta)/(Rv+10.67)

with Rv = 10.67(Tw-Ta)/(70-Tw).

Rv = R30 and Ta = 30 makes Tw = 59.5.

Nick

[mm]

On Sat, 28 Jul 2007 13:59:08 -0400, Larry Weil wrote:

In article ,
mm wrote:


Would it work to just buy infrared film for a standard 35 mm camera?
A good camera has a separate red dot on the lens to show where to set
the focus for infrared.

You would also have to buy a filter for the camera so only infrared gets
in. Infrared film also responds to visible light, so the filter is
necessary.

I think I bought that, but I can't remember.

The other problem may be finding someplace that can properly process
infrared film, my guess is that Walmart and the local drug store would
have no idea what to do with the stuff.

I'm sure. In NYC, I knew of a real photolab 2 blocks from City Hall.
You could drop film off at 2AM and pick it up at 4AM. Probably
quicker if you paid extra.

Baltimore sort of goes to sleep at night, but I'm sure in the phone
book or by asking at a camera store, I can find a real lab.

[Vic Dura]

On 28 Jul 2007 14:18:17 -0400, wrote Re
how to find out if walls of house are insulated?:

Rv = 0.67(Tw-Ta)/(70-Tw).

For instance, if you measure a Tw = 67.5 F wall temp with your $50 Raytek
MiniTemp when it's Ta = 30 F outdoors, Rv = 0.67(67.5-30)/(70-67.5) = R10.

Would this be valid for cooling? For example Ta=90F, Inside temp =
70F, Tw=72.5F
--
To email me directly, remove CLUTTER.

[[email protected]]

Vic Dura wrote:

Rv = 0.67(Tw-Ta)/(70-Tw).

For instance, if you measure a Tw = 67.5 F wall temp with your $50 Raytek
MiniTemp when it's Ta = 30 F outdoors, Rv = 0.67(67.5-30)/(70-67.5) = R10.

Would this be valid for cooling?

Sure, with no sun shining on the wall, eg at night.

Ta=90F, Inside temp = 70F, Tw=72.5F

That makes Rv = 4.7 (not much.)

Nick

[mm]

On 28 Jul 2007 14:18:17 -0400, wrote:

mm wrote:

Would it work to just buy infrared film for a standard 35 mm camera?

That kind of film won't show warm vs hot spots, and if it did, the heat
in the camera would expose it, unless the camera were cooled.

Darn. Oh, well. (Reply postponed because I was hoping to write a
more elegant reply.)