Attic insulation gurus needed

[CorCentral]

My in laws just bought a house (2400 sq ft) and they say that the previous owners had mthly electric bills ranging from $60.00-- $80.00 I actually saw the old bills and could'nt believe it. I own a 2000 sq ft house and my bills range from $110.-- $130.

I climbed up in their attic and saw a foil type material covering the original (1972) blown insulation. I cut a piece off for reference. PIC Sorry for the blurriness.

Anyone know what this stuff is called? Brand? (it's like a real thick aluminum material that has tiny holes in it to allow it to breath)

I was going to ask if this stuff would make that much of a difference but it's the only component our house does'nt have. Our house is 3 houses down from the in laws and both houses were built in '72 by the same builder.

One more note......... The day I checked their attic, the digital thermostat read 68f! (this was what the thermostat read, not what it was set at)
That was on a day when it was 86f outside (at 3pm) and the electric was not turned on yet. My house can barely hold 75f on a day like that.


I'll ask anyway....... Is it this material in the attic that's making this house so efficient?

 

[imported_Baloo]

The foil, on the shiny side, would reflect radiant heat. It can make a notable difference. Shiny side up helps keep it cool in the summer, shiny side down helps keep it warm in the winter. Shiny side both sides helps all year round.

 

[jersiq]

Looks like it may be Radiant Barrier.
I installed some in my attic when I owned my home in Houston, and I did notice a difference of ~10-15 degrees in the attic space.
However I had installed mine on the rafters. There are multiple different ways to install it, and in fact you can have shingles with a radiant barrier "built in"

I took temperature readings between two summers, using a regular digital thermometer.

However, the barrier I installed was a thin material, but that may just be a sign of the times.

 

[coldmeat]

i just insulate my house with money

 

[Sphexi]

Just looks like a thermal blanket of some sort. As already pointed out, the foil side reflects a certain amount of heat, so if your attic has plenty of ventilation in the summer, it could definitely keep the rest of your house cooler by reflecting the heat upward. Should be able to find it at Lowes or Home Depot or something like that.

Edit:

Here it is

$21 for 2'x25', so probably $200-$300 for the amount you'd need, but will probably save you that much in two or three years at the most.

 

[CorCentral]

Thanks for the info....... Hell, if it's going to be that cheap and it saves me $20.00--$30.00/mth on the electric bill, I'll have it paid for in about a year.

I will get back to this thread in a year and let you know the difference in my monthly electric bills.

 

[flamingelephant]

not a big fan of those reflective aluminzied insulations... overall, money is better spent adding insulation to R50 as opposed to products like that

 

[NoShangriLa]

Originally posted by: Sphexi
Just looks like a thermal blanket of some sort. As already pointed out, the foil side reflects a certain amount of heat, so if your attic has plenty of ventilation in the summer, it could definitely keep the rest of your house cooler by reflecting the heat upward. Should be able to find it at Lowes or Home Depot or something like that.

Edit:

Here it is

$21 for 2'x25', so probably $200-$300 for the amount you'd need, but will probably save you that much in two or three years at the most.

It look like duct wrap (flexfoil/reflectix bubble wrap with 1 or 2 aluminum foil layers) that can be use on ducting, water heater tank, and attic. That can also be had in size of 4'x 100' or 4'x125', their R rating is some where between R6 - R8.

The aluminium foil that the OP have is the fancy radiant barrier that use mainly to reflect solar radiation off you attic space. They tend to be install underneath the roof deck, below the rafters or in between the rafters.

Radiant barrier also come in pre made cardboard lenght & width of 48"x16".

Personally I have seen people use just pure house hold aluminum wrapper (wide width 1000' food packaging foil) and staple them to their roof rafters or craw space joists.

Increase the R value with traditional materials may work as well, but up to a point the relative return is low therefore it become more affective using a reflective surface to cut down radiant heat.

<-- mom cabin had food grade aluminum foil applied to the craw space joists.

 

[DrPizza]

Do you really think, though, that the only difference possible in the electric bill would be from that layer of aluminum? You seem to imply so, since you're calculating that you'd save the difference in electric each month. More energy efficient appliances, turning the computer on only when it's being used, etc., can make a HUGE difference in the monthly electric bill. For example, the difference between 2 refrigerators can be $5 (or more) a month in electricity.

edit:

I'll ask anyway....... Is it this material in the attic that's making this house so efficient?

It's not the only thing that's making the house efficient.

 

[arcas]

I'd consider removing the foil barrier and adding an additional 12-18" (R-24 - R-36) of blown cellulose insulation on top of the stuff that's up there originally. It's cheap and you can do it yourself in an afternoon.

Now's a good time to go through your house and identify any air leaks, too. Check around your exterior window frames for gaps. Also consider mounting a plexiglass plate in front of any fireplaces unless they're used frequently. You'd be surprised how much air leaks through a fireplace even with the damper closed.

 

[Fritzo]

I have 3' of blown fiber insulation in my attic...don't think this would help anymore Walking up there is like navigating through a pink snow drift.

 

[drnickriviera]

Originally posted by: Fritzo
I have 3' of blown fiber insulation in my attic...don't think this would help anymore Walking up there is like navigating through a pink snow drift.

Only problem is blown fiberglass sucks. It's the worst insulation you can put in, but I guess 3' makes up for it

 

[0roo0roo]

you have double paned windows?

 

[compuwiz1]

Originally posted by: arcas
I'd consider removing the foil barrier and adding an additional 12-18" (R-24 - R-36) of blown cellulose insulation on top of the stuff that's up there originally. It's cheap and you can do it yourself in an afternoon.

Now's a good time to go through your house and identify any air leaks, too. Check around your exterior window frames for gaps. Also consider mounting a plexiglass plate in front of any fireplaces unless they're used frequently. You'd be surprised how much air leaks through a fireplace even with the damper closed.

This might be a case of "if it's not broken, don't fix it."

 

[Fritzo]

Originally posted by: drnickriviera

Originally posted by: Fritzo
I have 3' of blown fiber insulation in my attic...don't think this would help anymore Walking up there is like navigating through a pink snow drift.

Only problem is blown fiberglass sucks. It's the worst insulation you can put in, but I guess 3' makes up for it

The builder made all their houses like that. It's supposed to be pretty standard now. I know it gets hotter than *&@#^$*@# upstairs in the winter, so it must work.