What to Use: Faced or Unfaced Mineral Wool Insulation

chipster_2007October 11, 2012

I have been looking at Roxul unfaced mineral wool insulation but just recently discovered another brand, Thermafiber, that does offer a silver faced product. The R values are the same and I was wondering which is the better type to use. It's going into the attic joist spaces where there is no insulation. Does the reflective facing really offer any more heat retaining/reflecting value? Which is the better choice Thanks

Thank you for reporting this comment. Undo
worthy

The facing serves as a vapour barrier. So, in a heating climate, you install it face down.

However, faced batts may be unnecessary or counterproductive depending on: 1) what vapour control layers are already in place in the ceiling and 2) your climate zone.

You haven't posted your Zone, so open the link below for the recommendatons for your zone.

Here is a link that might be useful: Vapor Control Layer Recommendations

    Bookmark   October 11, 2012 at 9:48AM
Thank you for reporting this comment. Undo
renovator8

Why are you interested in mineral wool for insulation?

    Bookmark   October 16, 2012 at 7:05PM
Thank you for reporting this comment. Undo
snoonyb

Foil faced insulations are a greater benefit in areas where sound reflection is needed.

    Bookmark   October 21, 2012 at 10:35AM
Thank you for reporting this comment. Undo
energy_rater_la

Does the reflective facing really offer any more heat retaining/reflecting value?

no.
for reflective surface to reflect, it needs
a minimum of 3/4" or larger air space to work.
facing the reflective surface down..(as in vapor barrier
to warm side).. puts reflective surface on attic floor.
facing reflective side up..would work in hot climates
as a radiant barrier..but only until dust buildup
reduced reflectivity.

I used fiberglass batts in my attic. all
unfaced. first layer in joist bays, second layer
across joist bays.
just what I did in my own house.

before adding insulation, air sealing attic floor
to living space below is a good investment.
if you minimize air flow through insulation, it
will perform to its rated R-value.
caulking wire penetrations, plumbing penetrations,
sealing around vent fans for baths & stove vent
penetrations all help.

if your ductwork is in
the attic you should seal ductwork prior to any
added insulation.

it is much much easier to work in attic prior to
insulation. it will never be as easy again.

where are you located?
I'm interested in what you chose and why.
if you don't mind sharing.

for further reading on vapor barriers here
is a link to a blog that has some great info.
peruse some of the earlier postings also.

http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/54110/You-Don-t-Need-a-Vapor-Barrier-Probably

best of luck.

    Bookmark   October 21, 2012 at 7:55PM
Thank you for reporting this comment. Undo
renovator8

Sound energy would not be affected by a thin layer of aluminum foil but a sheet of lead is very effective against lower frequencies if it is hung lose in the wall cavity.

    Bookmark   October 22, 2012 at 1:32PM
Thank you for reporting this comment. Undo
chipster_2007

Thanks for all your responses. I think I am going to choose mineral wool for the following reasons:1 there are floor boards that do not fit tightly together, so the thought of blowing in cellulose into these spaces concerns me. It would be very dusty up there and the area is used to store old memories. Second, air sealing is so important, if I have to remove the boards to air seal, I might as well put down a product with the best R value I can find that will not compress over time losing its efficiency. Also I would never consider fiberglass for those reasons as well as the fact that it is soooo itchy to handle!!! The one thing I do not like is the weight of the packaged product. I am trying to think of the easiest way to get it up 3 flights of stairs to the attic. Any good ideas?

    Bookmark   October 23, 2012 at 1:53PM
Thank you for reporting this comment. Undo
columbusguy1

What about a rope and pulley system to hoist it up to the window?

    Bookmark   October 23, 2012 at 5:43PM
Thank you for reporting this comment. Undo
worthy

The one time I personally installed Roxul rock wool I found it much more itchy and irritating than fg. (Not everyone has the same reaction.) The bundles are heavier than fg and don't compress. As well, it's not easy to cut; contractors regularly use table saws or specialized equipment.

I'd strongly suggest you work with a bundle before ordering any more. If you find it's not for you, it's not wasted money. Just put in what you have and finish the rest in another insulation.

    Bookmark   October 23, 2012 at 8:44PM
Thank you for reporting this comment. Undo
energy_rater_la

assembly line.
line all your buds up from truck to
attic and pass bundles (or batts)
along into attic.

I had to haul batts through my
house & into attic via closet & tiny attic
hatch. it was more work than putting insulation
in place.

if you have a window the pulley & rope
isn't a bad idea.

best of luck.

    Bookmark   October 25, 2012 at 7:37PM
Sign Up to comment
More Discussions
Yikes. I just bought an 1898 Victorian house
Hi, I have always loved old homes and had the opportunity...
adamsmile
New windows in kitchen for 1926 house
We are planning a kitchen and bathroom remodel in our...
crl_
Should we try to reuse old windows?
I am not sure how old the windows in our second floor...
prairiemoon2 z6 MA
stone house
Do any of you out there own a real stone house? Not...
seydoux
Interlocking window weatherstrip question
The windows in the house have interlocking metal weatherstripping,...
rjs20
Sponsored Products
Indoor Area Rug: Metro Blue 7' 9" Round
Home Depot
Slamp | Punctum Wall Sconce
$855.00 | YLighting
Chintaly Prospect Adjustable Swivel Bar Stool - 0379-AS-BLK
$143.22 | Hayneedle
Serenade For You Silver Jacobean Cafe Noir Eight-Light Chandelier
Bellacor
Disk 6" Nickel 15 Watt LED Ceiling Light
$64.99 | Lamps Plus
Keep-Kool 16.9-ounce Double-wall Stainless Steel Mugs (Set of 4)
Overstock.com
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™