Question re "Rock Wool" Insulation

[legaleagle1971]

I am building a 4700 sq. ft. home in Dallas, Texas and the builder has an upgrade option of "rock wool" insulation. I'm wondering if the return on investment is worth upgrading -- especially in such a warm climate as Dallas. The builder is charging a pretty penny for the upgrade (over $8000). Any help is appreciated!

[cem-bsee]

what is the R value?
applied where?

ask for a load calculation to show the reduction in losses, both winter & summer, per Manual J method.

else, be sure YOU are understanding what the salesman is saying, then ask for facts -- not hype

[eastcreek]

I know of another general contractor that advises using a thermal barrier for hot climate conditions. My guess is that it can be installed cheaper than the above quote....especially if you do it yourself afterwards! :D

[mchild]

I don't know anything about rock wool. But, if it wee me I'd spend extra on spray foam and get a much tighter home overall. Do a seach of this site for spray foam as there was a recent discussion with lots of detail as to the cost savings in going that route.

Here are a couple to get started with:

http://hvac-talk.com/vbb/showthread.php?t=140404

http://hvac-talk.com/vbb/showthread.php?t=141066

[stvc]

What are you upgrading from? I didn't even know you could still get rockwool installed, see it on occasion in very old homes though. I'm in the northeast, pehaps it's more common elsewhere. For horizontal open blow Rock wool has a R-value 2.6 - 3.6, cellulose 3.2 - 3.6, fiberglass 2.6 - 3.0 per inch. I like cellulose, you get free airsealing with it and is very economical. I have no idea what rockwool is worth or why anyone would consider it better.

[CottyGee]

I don't know anything about rock wool. But, if it wee me I'd spend extra on spray foam and get a much tighter home overall.
Ditto. I think a cathedralized attic with a radiant barrier would be the way to go! At least it would for hot and arid climates like mine. I *THINK* the same applies to hot and humid like your climate... :confused:

[Shophound]

Rock wool...twice as itchy as fiberglass!

My last house had that crap up in the attic...it compacted over time so we threw fiberglass batts over it to upgrade our insulation level.

For Dallas (I am to your west in Cowtown), I think a radiant barrier beneath the roof decking (one product name is called "Techshield") is a better payoff than the rock wool. If you have 6 inches of fiberglass, and 6 inches of rock wool, and they both yield similar R values, how can the extra cost be justified?

For your builder, make him build you a tight house. You could fork out eight grand extra for rock wool and still be running your a/c system to death with a leaky house and leaky ductwork. And being how I'm pretty familiar with how most new homes are built in Dallas, you stand a good chance of getting the typical spaghetti mess flex ductopus install, which will sit up there and laugh at your rock wool insulation.

If it were me I'd nix the rock wool, go with fiberglass and radiant barrier, and carefully monitor the HVAC install. If it's done poorly, it's gonna eat your lunch no matter what. It makes little difference that your house is 4700 sq. ft. and no doubt has a healthy price tag on it...many builders ignore that aspect and hire the cheapest HVAC sub they can get...it's all about the margin, IMO. And yes, the builder is in business to make money, nothing wrong with that...how he makes his money will hinge on his ethics.

[legaleagle1971]

I unfortunately lost the brochure that the salesman gave me, so I do not know the R-values that they are claiming for the rockwool.

Here is what is standard if we don't pay for an upgrade:

Exterior walls of improved living areas--fiberglass batt R-13
Garage ceilings with living areas above--fiberglass batt R-19
Vaulted ceilings and attic walls of improved living areas--fiberglass batt R-19
Non-blowable ceilings of improved living areas--fiberglass batt R-19
Blowable ceiling of improved living areas--fiberglass blown R-30

We are installing the foil radiant barrier, so I'm thinking the rockwool may be overkill. From what I can gather, this rockwool stuff helps more with sound insulation and retarding fire than it does with cooling costs anyway.

[Vivid]

that was my understanding of Rockwool, its great for sound insulation...

Just and FYI I am building a 4000sq/ft home in ATL and it is costing me $5K to upgrade to spray foam (icynene) which after the HVAC calcs came back it wound up a near no cost option because I now need 2.5 tons less HVAC and I should hit my ROI point within a year.

[hvacbear]

Spray foam is the way to go.

[roymcoy]

My understanding is that rock wool would be denser & more resistant to air currents flowing thru it than blown-in fiberglass. Fiberglass batts are probably better than blown-in in that respect also. Stated r-values most likely don't take air currents into account. Can't imagine why there would be such a huge cost difference for the rock wool, however.
None of these are as efficient as spray foam. But with foam you'll need to make certain you get an HVAC system with enough fresh air ventilation & humidity control to avoid air quality & mold problems which can result from the house being too "tight".

[CottyGee]

Can't imagine why there would be such a huge cost difference for the rock wool, however.
LOL - you obviously haven't bought a tract builder home then! That's the way they do EVERYTHING.

Figure it like this - whatever it would cost you as a homeowner to hire the most expensive company around to come out and install "X" (just about any upgrade most tract home builders offer). That's the "extra" charge to have it done. They rape you.

On our house, they wanted $4,000 extra to install ceramic tile instead of vinyl - laundry, kitchen/dining, 1 bathroom, and one "water closet" room. A few years after we moved in, we ripped up the vinyl, bought tile that was probably nicer, and had it all installed, for a total cost of $1,200. :mad: http://hvac-talk.com/vbb/images/icons/icon13.gif :mad:

[roymcoy]

LOL - you obviously haven't bought a tract builder home then! That's the way they do EVERYTHING.

On our house, they wanted $4,000 extra to install ceramic tile instead of vinyl - laundry, kitchen/dining, 1 bathroom, and one "water closet" room. A few years after we moved in, we ripped up the vinyl, bought tile that was probably nicer, and had it all installed, for a total cost of $1,200. :mad: http://hvac-talk.com/vbb/images/icons/icon13.gif :mad:

Personally, I'd never hire anyone to do anything to my house if I was confident I could do the job well myself.

[skippedover]

Insulation is all absolutely useless if the wind is blowing through it. Well, not quite useless. It makes a good air filter so when the wind comes out the other side is cleaner! Too much emphasis on insulation and none on decreasing airflow. The most important feature for any home is to seal the air leaks. Not just to the outdoors but up through the wall spaces, electrical wire penetrations, recessed light fixtures, virtually anything that penetrates the indoor room envelope. If you get all that under control, then insulations make a big difference. Everyone who is recommending spray foam has the total nut cracked! It seals the envelope AND insulates, all for one cost. The only thing you have to watch out for is that after the foam is installed, some yahoo doesn't come in and start cutting it all around to install his new ceiling vent fan or something. Seal the envelope, then insulate. Do the isonene and you've got the best there is, unless you're going to use straw. Don't laugh guys, straw is even better than isonene for insulation. More on that another time.

[CottyGee]

Don't laugh guys, straw is even better than isonene for insulation.
Guy I bought my dog from was a Veternarian who lived in a rural community several hours from the city. He had built his house himself - out of straw bales! Stucco'd over the outside and plastered over the inside. Those were some REALLY thick walls! http://www.herfersparadise.net/portal/modules/Forums/images/smiles/icon_lol.gif

[Shophound]

Guy I bought my dog from was a Veternarian who lived in a rural community several hours from the city. He had built his house himself - out of straw bales! Stucco'd over the outside and plastered over the inside. Those were some REALLY thick walls! http://www.herfersparadise.net/portal/modules/Forums/images/smiles/icon_lol.gif

Straw bale construction is not an uncommon "alternative" building method. My brother considered it for the house he is about to build but is probably going to go with the "Rastra" method instead, which is basically insulated concrete forms. High R value, low sound transmission, tight envelope, not ridiculously hard to erect...not a bad package.

[fire]

Rock wool mineral wool Same thing. It has slightly higher r value than fiberglass. Comes in batts. better sound absorbtion and will not burn.

[pstu]

I grew up in Dallas and get the idea that sloppy construction is your clear and present danger, even with a luxurious house. I'm a homeowner in S.Texas and sympathise. My parents had a custom house built in Dallas by a family member who was a perfectionist, it has extraordinarily low energy bills. For that I credit mainly good design and craftsmanship, it does *not* have tons of insulation.

I would challenge your builder with a series of 3rd party expert inspections to critique the important things while there is still time to fix them in the initial construction phase. That would include guaranteeing air tightness with a blower door test, try to make a contract which is win-win if he does it well. Is it possible to have ductwork inside conditioned space instead of sitting in the hot attic? That is another thing that would be better than paying 8 thou for insulation. People never suspect just how important ductwork is -- it is essentially a custom engineering job done by people who seldom are good designers. You could try to guarantee the equipment selection is done by ACCA Manual S, then Manual D to guarantee the required airflow to each room without excessive back pressure. I would try to write into the contract the equipment would operate with a TESP (total external static pressure, essentially like back pressure) less than 2/3 the limit of the equipment. You could require performance guarantees such as the AC being able to maintain humidity less than 55% RH at 75F inside.

I imagine the builder would have to be brought kicking and screaming to the table for most of these contractual suggestions. Actually guaranteeing good craftsmanship and design is not the normal business practice. Who wouldn't prefer to just sell a bunch of window dressing for far more than it's worth? I'm neither a pro AC guy nor a pro builder, so these are just some ideas.

Best of luck -- Pstu

[mark beiser]

As someone who has to work in attics frequently, I HATE ROCK WOOL!
As insulation, it is superior to fiberglass though...

[cem-bsee]

the RockWool of the 1940s was asbestos!
has the tradename been sold to someone else who is using a different material?

[CottyGee]

the RockWool of the 1940s was asbestos!
has the tradename been sold to someone else who is using a different material?
Found this...



rock wool (http://iaspub.epa.gov/trs/trs_proc_qry.navigate_term?p_term_id=4307&p_term_cd=TERM)

* A generic term for felted or matted fibers manufactured by blowing or spinning threads of molten rock, slag, or glass. The material is used for thermal insulation.(Source: BJGEO) (Source: European Environment Agency (EEA), European Topic Centre on Catalogue of Data Sources (ETC/CDS): General Multilingual Environmental Thesaurus Term Detail)

[RoBoTeq]

Rockwool, whether the old asbestos or whatever they are now using in place of asbestos, has got to be some of the nastiest stuff to work around.

That stated; rockwool is a great insulator, good sound attinuator and is fire retardent. These are three great reasons to have rockwool blown in to any home. You will reduce your cooling and heating usage with a product that not only does a good job at insulating, but also prevents drafts due to its' density.

Rockwool is one of the determining factors that got me to make the decision to go from contractor to manufacture rep.

[RoBoTeq]

Found this...

Wow GollyGee, you're a regular HVAC Wikapedia.

[CottyGee]

Wow GollyGee, you're a regular HVAC Wikapedia.
I'm just tryin' to figger out just what exactly rock wool is! I've heard of it before, but I don't think I've ever seen it.

Found sumptin better than the EPA definition...



Rock and slag wool (http://www.naima.org/pages/resources/safety/rock1.html) fall within a group of materials historically referred to as man-made vitreous fibers, now known as synthetic vitreous fibers (SVFs) - reflecting the glassy, non-crystalline nature of these materials. The mineral wool form of SVF was developed in the mid-1800s by melting slag and spinning it into insulation. Rock wool is made from natural minerals like basalt or diabase. Slag wool is made primarily from iron ore blast furnace slag.

Rock and slag wool insulation products play a significant energy-savings role by reducing energy use in homes, office buildings, businesses and manufacturing plants. In addition to providing thermal insulation, rock and slag wools absorb sound and, with a vapor retarder, help control condensation. Because they are non-combustible and have melting temperatures in excess of 2,000 degrees Fahrenheit, they are also used to prevent the spread of fire. Rock and slag wools will not support the growth of mildew, mold or bacteria, when tested in accordance with the specifications of the American Society for Testing and Materials (ASTM C 665).

The primary uses of rock and slag wool are for acoustical ceiling tile; residential, commercial and industrial insulation; and spray-on fireproofing. The excellent thermal resistance of these materials is a major factor in their use as residential and commercial insulation, pipe and process insulation, insulation for ships, mobile homes, and domestic cooking appliances, and a wide variety of other applications.

[RoBoTeq]

I'm just tryin' to figger out just what exactly rock wool is! I've heard of it before, but I don't think I've ever seen it.

Found sumptin better than the EPA definition...

Another cut and paste definition. This one void of any accuracy pertaining to the previous use of asbestos, which we HVAC professionals know is a fact. What else is this source not disclosing?

Not that you are not trying to help a fellow HO, but I believe that other HOs come here for the opinions of the professionals on this forum. Many of us in the profession "have" seen and worked with rockwool and can give experience related opinions on the subject. Any HO can look up definitions of materials.

Lets stick to the subject at hand that HOs post for the pros on this forum, eh?

[mark beiser]

Another cut and paste definition. This one void of any accuracy pertaining to the previous use of asbestos, which we HVAC professionals know is a fact. What else is this source not disclosing?

Not that you are not trying to help a fellow HO, but I believe that other HOs come here for the opinions of the professionals on this forum. Many of us in the profession "have" seen and worked with rockwool and can give experience related opinions on the subject. Any HO can look up definitions of materials.

Lets stick to the subject at hand that HOs post for the pros on this forum, eh?

I haven't ever seen any information indicating that rock wool has ever been manufactured with asbestos in it, or that any has been found that was manufactured with asbestos contamination. I'm not saying that it hasn't happened, just that you are the very first person I have seen say so.

Nasty horrible stuff to work around though, lol.

Now Vermiculite, an entirely different product, has had a history of asbestos contamination, depending on what mine the raw materials used to make it came from.

[RoBoTeq]

I haven't ever seen any information indicating that rock wool has ever been manufactured with asbestos in it, or that any has been found that was manufactured with asbestos contamination. I'm not saying that it hasn't happened, just that you are the very first person I have seen say so.

Nasty horrible stuff to work around though, lol.

Now Vermiculite, an entirely different product, has had a history of asbestos contamination, depending on what mine the raw materials used to make it came from.

Just a few posts up Mark;

Today, 11:43 AM
cem-bsee

Location: Huntsville,AL
Posts: 3,484

the RockWool of the 1940s was asbestos!
has the tradename been sold to someone else who is using a different material?
__________________
harvest rainwater [drywells, ponds],make SHADE, use HVAC mastic,caulk all wall seams,insulate!


Check out this partial list of asbestos bearing materials. Not that I think asbestos is the demon it has been made out to be, quite the contrary. I believe that asbestos is a wonderful insulator that is also fire retardant and properly handled is as safe if not safer then some of the current alternatives. Note that Mineral wool is listed as well as Rockwool. They are the same product.

AsbestosAsbestos Industry
ProductsL through Z
You may not realize all of the types and forms of materials that contained asbestos. Our research has disclosed that asbestos was used in the following products. People who worked with or came into contact with these products are at risk to develop asbestos diseases including malignant mesothelioma and asbestos related lung cancer.

Products: A-C, D-K, L-Z

lagging adhesive
lagging cloth
lagging tape
lagtone
lap seal
leggings
limpet spray
limpet spray asbestos
Litecase 30 S
LK block
LK pipecovering
LK12 calcium silicate
LK-12 calciom silicate
LT block
LT pipecovering
LT sealer
Magnesia block
Magnesia cement
Magnesia covering
Magnesia insulating cement
Marinite insulating panel
Magnesia pipecovering
masonry fill
mastic
mastic adhesives
metal mesh blanket
Micabestos
Micarda plate and tube
millboard
Mills boiler
mineral wool insulating cement
mineral wool
mineral wool blankets
mineral wool blocks
mittens
mitts
molded cork pipecovering
Monoblock
Monofoam
Monokote
Monoplast
Mono-ply insulating cement
Monospray
mortat mix
Multiply block
Multiply pipecovering
Mundet asbestos cement
Mundet pipecovering
Mundet products
Mundetblock
Mundetcork
N-1200 block
National gypsum sheetrock
National gypsum board
Navy sealer
Navy standard hairfelt
Newtherm pipecovering
NG Asbestos millboard
Nicolet pipecovering
Nicolet/Keasby products
non-sweat pipe insulation
non-sweat pipe covering
Novabestos
Novatex
Nsulkote
nuclear reactor w/comp
OCF asbestos cloth
OCF products
one coat cement
one coat insulating cement
one coat cement
one coat finishing cement
Osnaburg
Owens-Corning 660 cement
Owens-Corning asbestos cement
Pabco
Pabco block
Pabco caltemp pipecover
Pabco F-1 hydraulic cement
Pabco pipecovering
Pabco super caltemp block
packing
packing material
paint
paper
paper tape
patching plaster
Perf-a-tape
Perlite
Perltex spray surface
Perltex super 40
Permaboard
Permiseal
Philip Carey products
pipe insulation
pipecovering
Pitcote
Pittsburgh Corning products
Pittwrat
plaster
plasticork
Plibrico cement
Plicaste cement
Plisulate cement
Polybestos cloth
Pork chop boiler
Porterlag
Portersite
Powerhouse cement
Prasco pipecovering
preformed pipe wrap
pumps
pumps and packing
pumps with packing
putty
Pyrobar blocks
Pyrokure
Pyrokure paper
Pyrokure tape
Pyroscat fireproofing
Pyrospray
Pyrotex
quick-setting joint compound
quick treat compound
quickset cement
R & I block
R & I unsulating cement
Racko asbestos cement
railroad asbestos
railroad electrical arc chutes
range boiler jacket
raw asbestos
raw asbestos fiber
Raybestos amosite blanket
Raymark brake linings
Raymark products
ready mix joint compound
Red Top plaster
Red Top products
refractory cements
regular pipecovering
Rexalt
Rhinoestos cloth
Riley Stoker asbestos products
Rockwool insulation cement
Rockwool asbestos blanket
Rockwool asbestos blanket
Rockwool blanket
Rockwool block
roofing felt
roofing paper
roofing product
rollboard
rope
rope packing
roughing cement
Ruberoid block
Ruberoid calsilite
Ruberoid cement
Ruberoid hi-temp cement
Ruberoid pipecovering
S&K ranger boiler jacket
Safekote cement
Salmo glazed aircell
Seal fast adhesive
sealer
sheet packing
sheet rope
sheetrock
sheets
shingles
silicate calsilite
Silvabestos cloth
sleeves
Smith & Kanzler products
Sniper 3000 cement
spackle
Sparkfast adhesive
Speedlag
Splicegard
sponge felt
spray fireproofing
spun felt
Stalastic
steam generator
Stic-Tite cement
Stic-Tite finishing cement
Stik-Tab cement
stone corrugated sheets
Super "66" insulating cement
Super 48 cement
Super 711
Super D blockinsulate
Super finish stic-tite cement
Super finish cement
Super high temp cement
Super insulation tape
Super light block
Super powerhouse cement
Super stic-tite cement
Super48 insulating cement
Superex block insulation
Superex pipe covering
Super-light cement
Superseal packing
Supertemp blocking
supplied/distributed ASBE
supplied/distributed PRO
supplier
T/NA insulation jacket
tape
tar paper
temp check block
temp check pipecovering
terra lite
Terrybestos
Themobestos metalon P/C
Therm Block
Thermabestos block
Thermabestos cement
Thermaguard
Thermaguard asbestos cloth
Therma-K block
Therma-K pipecovering
Thermalcoat
Thermasil
Thermasil block
Thermasil cement
Thermasil pipecovering
Thermasil-general
Thermo 12
Thermo 12 pipecovering
Thermo pipecovering
Thermobestos
Thermobestos pipecover
Thermoblock
Thermokote
Thermolite
Thermon heat cement
Thermotex B
Thermotex B (paper)
Thermotex B weatherpro
thin set materials
Titegrip cement
Transite board
Transite pipe asbestos
Tri-bestos
Tri-calite block insulation
troweled coating
turbines
turbines with ancill insulation
U.S. gypsum spray
Unarco amocel pipecover
Unarco board
Unarco cloth
Unarco insulating cement
Unarco mineral wool
Unarco products
Unibestos
Unibestos block
Unibestos pipecovering
Unibestos products/distribution
USG aircell pipecover
USG hairfelt pipecover
USG woolfelt pipecover
Util thermal finish cement
valve rings
valve stem packing style
valves
valves and packing
various JM products
V-Dent pipe insulation
Vee block mix (relabel)
Vermont asbestos
Versakote
vinyl gypsum adhesive
vinyl wallpaper
Vitricel asbestos sheet
Vitricel cement
wallboard
water tube boiler
waterproofing
Weathercote asphalt CM
Weatherkote
Weatherseal
weld-on cement
welding rods
white loose wool
white surface cement
white-cement
wick
wire mesh blanket
wires
Woolfe LT pipecovering
Woolfelt block
Woolfelt covering
Wovenstone
yarn
yellow insulation
Zono plaster aggregate
Zono-coustic
Zonolite acoustic plaster
Zonolite asbestos
Zonolite cement
Zonolite decorators
Zonolite dry cement
Zonolite high temp
Zonolite mono-cote F.P.
Zonolite plaster
Zonolite spray insulation
Zonolite spra-tex

[mark beiser]

Interesting, they don't have vermiculite on that list....

With any kind of material made from mined minerals, there is the chance for asbestos contamination if asbestos was in the ground in the area it was mined, so it wouldn't surprise me if there was some contaminated rock wool manufactured out there somewhere.

I remember several years back, like 10 or so years ago, there was a little bit of public concern about rock wool insulation in the Fort Worth area, but no asbestos was found in any of the samples in the study that was done, I think it was Texas A&M that did the study, but I'm not sure.

I know I sure have been exposed to a ton of it....

Oh well, everybody dies of something. ;)

[Carnak]

I think the extra for using icynene and sealing up the attic would be less than the extra for the rock wool.

Solves the problem of air from the attic, passsing through any insulation and getting filtered before adding its high heat and humidity to the space below :)

Blow about 5.5" along the under side of the roof sheathing, be about a $1 a square foot more than R19, and more effective than 2 feet of fibre glasss or rock wool blown in at the ceiling plane. If you have gabled end walls in the attic foam them or use batts.

Sloping roof has more square feet than a flat ceiling. Then spend the rest of the money to make sure the attic is properly sealed where the walls meet the roof trusses.

[Carnak]

Interesting, they don't have vermiculite on that list....

With any kind of material made from mined minerals, there is the chance for asbestos contamination if asbestos was in the ground in the area it was mined, so it wouldn't surprise me if there was some contaminated rock wool manufactured out there somewhere.

I remember several years back, like 10 or so years ago, there was a little bit of public concern about rock wool insulation in the Fort Worth area, but no asbestos was found in any of the samples in the study that was done, I think it was Texas A&M that did the study, but I'm not sure.

I know I sure have been exposed to a ton of it....

Oh well, everybody dies of something. ;)
vermiculite must be what I called zonolite. Stuff that was like granules you poured into wall cavities

http://www.cbc.ca/national/news/deadly_dust/

[mark beiser]

Yeah, I think zonolite is/was one of the brand or trade names for vermiculite.
I have never actually seen any though.

[wg2012]

the RockWool of the 1940s was asbestos!
has the tradename been sold to someone else who is using a different material?


Another cut and paste definition. This one void of any accuracy pertaining to the previous use of asbestos, which we HVAC professionals know is a fact. What else is this source not disclosing?

Not that you are not trying to help a fellow HO, but I believe that other HOs come here for the opinions of the professionals on this forum. Many of us in the profession "have" seen and worked with rockwool and can give experience related opinions on the subject. Any HO can look up definitions of materials.

Lets stick to the subject at hand that HOs post for the pros on this forum, eh?

Where are you getting this information? I haven’t been able to find anyone who can back up the idea that asbestos was used in RockWool (or any other loose fill home mineral wool insulation).

Does anyone have a single report or study that confirms this?

[HSI]

Go tech shield (foil on the underside of plywood) upgrade on the plywood for the roof it keeps the attic cooler.