Why Cellulose Insulation is Better than Fiberglass Insulation

[@Jonb01z28]

This shows the exact problem i'm having in my home in FL. 75% of home has blown cellulose which works fairly well but over a faulted living room it has fiberglass. Ceiling dry wall temp in vaulted living room reach anywhere from 78-104 on a 90 degree day, rest of ceiling around house stays pretty constant at 74-75. Looking very soon to had more cellulose around entire attic as well as get rid of fiberglass on vaulted area to help improve comfort in home.

[@butlerfranz]

Thank you for this informative video. I am a general contractor and have more recently needed to understand insulation types. It has been challenging to find unbias information. Fiberglass manufacturers of course claim their product is better, however, their arguments lacked a logical conclusion. Things did add up and I settled on cellulose, but still had concerns about fire and mold. This video has assured me I made the right call.

[@carlosb3169]

thank you! your channel and this video is still helping a ton of people even 10 years later!

[@victorbunch1442]

Very informative video sir. You have singlehandedly changed my direction of thought of how I should insulate my UNinsulated garage walls AND my open walled 24 X 30 ft shop. Thank you very much😁

[@newstart49]

I had cellulose installed in my old 1946 walls. The house is so quiet, it's spooky. Blew it in the attic and went from a 4 ton ac (125k btu heater) to a 2.5 ton ac and I heat the home with only 38k btu's of heat. I also covered the ducting.

[@ColeB-jy3mh]

newstart49 Hey I read somewhere that the chemicals disappear making the insulation burn after 2-3 years...... would you be able to check if that’s actually true for me please??!??!

[@fartman2269]

@@ColeB-jy3mh No, that is incorrect. That is another urban legend started by fiberglass sales people.

[@rezaghahreman86]

I have a old house in Toronto Canada. I am wondering if I can use cellulose for wall insulation. Doesn't make rot issue during time?

[@fartman2269]

@@rezaghahreman86 Cellulose insulated walls perform quite well compared to fiberglass, you shouldn't have any problems with "rot", as cellulose is hygroscopic, meaning it is capable of absorbing moisture, and able to release that moisture as well. As long as you don't have any water intrusion from the exterior, you should have no issues.

[@HsingSun]

​@@fartman2269 In Florida, you bet hurricane and windstorm could cause leak through the roof.

[@marct4900]

There are many reasons why we prefer cellulose over fiberglass insulation. One is resistance to air flow. Take a look at the the material that your furnace or air handlers filters are made of - it may be fiberglass. Filters are designed to all air movement through them. Blown in cellulose insulation is 2-3 times denser than fiberglass insulation. Studies comparing blown in cellulose insulation vs. fiberglass insulation show that cellulose insulation was 38% tighter and required 26% less energy. A Princeton University study shows, a group of homes with blown in cellulose insulation in the walls had an average of 24.5% reduction of air infiltration compared to fiberglass insulation, with only the walls insulated. A similar study, the Leominster MA Housing Project for the Elderly found that, a building with blown in cellulose insulation compared to a building with R-13 fiberglass batt insulation in the walls and R-38 fiberglass batt insulation in the ceiling, had 40% lower leakage.

[@bloodsoakedwhiskers]

When you stick your hand into fiberglass it already feels hot inside. When you stick your hand inside of cellulose it has a slight cold feeling. Even on a very hot day... It's great stuff....

[@MikeJones-rk1un]

No one mentions you shouldn't touch fiberglass insulation or even be near it without a mask and protective suit. Don't put it in your house.

[@Joewalshe38]

It's worth mentioning that fibreglass insulation compacts over time so your 4" ceiling insulation laid 10 years ago might now be 1/2". It sags in stud partitions meaning there is no insulation at the top of walls where most needed.

[@kilx81]

My mom is in the middle of renovating her new home. The brick walls were not insulated. Now there about 80 in the wall. I'm amazed that even though the attic is poorly insulated how much warmer it feels inside. And before we could hear people talking outside. Now I can't.

[@desperado77760]

does any paper need to be put down first? What about dust coming into the house from cellulose as it ages and settles? Is this just blown in or is something done to make dense-pack? What I'm asking I guess is, if put in the attick is it just blown in or does it need to be compressed some way?

[@Veevslav1]

Your comparison was flawed. That particular lamp you used conveys a portion of its heat via light coming in contact with the surface. Light was penetrating to the thermometer. Which makes sense since fiberglass is supposed to use more air to try and stop temperature spread. We could explain more about it, but. Going forward the test should have had a thin piece of something else that completely stops light penetration. AKA black tar paper or for the most accurate, a piece of sheathing material.

[@TheRealBiggerAl]

Veevslav1 and instead of placing the thermometer at the same depth in each box it should be placed at the same “R value” depth.

[@bmo5082]

Ya seeing this test is bogus. Who on earth exposes their insulation to the sun?

[@tlbfarm4473]

At 5:00 when talking about burning insulation materials, you don't mention Roc Wool. Why not? What is Rock Wool's burning characteristic's vs. cellulose, fiberglas etc.?

[@jccbsl1]

Wait a minute. Something doesn't make sense. Both insulation samples are labeled R13 which, as I understand it, means they should have the same resistance to transfer of heat.

[@charlescrockett6208]

BECAUSE R VALUE IS 72 DEG F. FIBERGLASS LOSES R AT LOW TEMPS AND HIGH IN A BELL CURVE. IT LAYS DOWN WHEN YOU NEED IT CELLULOSE IS ALMOST FLAT LINE

[@parkeranderson5074]

Charles Crockett WHAT DID YOU SAY???

[@megw2359]

@@parkeranderson5074 I think what he's saying is that when they test materials for the R values, they do it under very controlled conditions like only at 72 degrees. But if you look at performance at higher and lower temperatures than 72 degrees, the R value of fiberglass is actually much lower than advertised. The graph of R value of fiberglass looks like a bell shape: highest at 72 degree but dropping off dramatically at high and low temperatures. Graph for cellulose is nearly flat, meaning that the R value for cellulose stays at the advertised number regardless of how hot or cold the environment.

[@Soprano0913]

Great video what about comparison of cellulose vs rockwool

[@markchidester6239]

So what you are saying is that the R value is actually higher per inch than fiberglass?

[@gsneff]

Two types of insulation should do as well against fire: aircrete, which you mentioned, and rockwool.

[@WilliamMcCormickJr]

Over time, many years, about 20 to 25 years the cellulose insulation becomes flammable. It may be the dust that accumulates over time that causes it. It actually ignites by just touching a drop light with an incandescent bulb against the material. Many people that have homes that are old and have this material in the ceilings between the ceiling joists, actually build protective, constructions to keep this material away from light fixtures. Because it has started to smolder and ember, just being near the fixtures. Sincerely, William McCormick

[@larrymaloney877]

+William McCormick, thirty year old cellulose has been tested and shows no loss of fire retardant. . During the same thirty years installed fiberglass has remain non-fire retardant and not approved as a fire back or fire wall, Cellulose hos both those certificates. In fact , the paper used to cover fiberglass to protect the public catches fire and contributes to the spread of house fires. Your high pressure lies may trick ignorant folks into buying inferior fiberglass but sooner or later, an intelligent buyer gets that home and immediately has us vacuum out all the nasty fiberglass and install fire-retardant, superior cellulose insulation. They are amazed by the difference.

[@larrymaloney877]

+techtalk, sounds like you are gullible.

[@WilliamMcCormickJr]

I took a sample from a house, that experienced AC installers had started several areas of the insulation smoldering with red embers, by only touching the drop light to the insulation. Even after they started one area smoldering and extinguished it they started others. The house filled with smoke to a point it was suffocating. The guys in the attic got sick but were able to find and extinguish all the different areas that were smoldering. I experimented with it, and it was far too unstable to use as an insulation. I am going to see if I have some left. If I do I will make a movie of it being heated. If I was in the forest and I needed to make a fire without matches, I would want this stuff for kindling. I was told by a person that had spent a good portion of his life as a high ranking fire department representative that the insulation had been banned, for very real, very sound reasons. When I saw it again in Home Depot recently I thought the world had gone quite mad, for sure. Sincerely, William McCormick

[@larrymaloney877]

+techtalk , a chemistry major would not confuse boric acid with "things that have a half life". We are not talking about carbon dating 50 million year old dinosaur bones. The information you seek is available from the manufacturer. Antidotally speaking, I've personally removed cellulose from my parents home  which I personally insulated in 1974 and tested it for fire retarding qualities. It was fine.. Again, pay attention please,  Cellulose, not Fiberglass, is rated as a one-hour and a two hour fire wall. Cellulose is also one of the few means to create a fire stop. Again, those test results and certifications are available from each manufacturer who cares to have their particular product tested. Your opinion is between you and he manufacturers. To challenge their test results I suggest you contact one of them.

[@larrymaloney877]

+William McCormick , please direct me to the newspaper article that followed the alleged incident and which attorney is handling the liability lawsuit. I assume you can add credibility to your tale by documenting these obvious follow up results to your story. Or can you?

[@BrandonTran]

Wow incredible! I had this installed in my first house, walls and ceiling. I'm in my 3rd house now and it has fiberglass. I'm sad about that...

[@1951walton]

Sadness is a very poor inulator!

[@pedrompneves]

Dear Larry Janesky, Thank you for all the information about fiber cellulose. I am from Portugal, and I will apply the cellulose insulation. The company that is going to apply it recommends 15cm (about 6 inches) high in the attick floor (cement attick). Do you think that's enough to do a good performance in Portuguese weather (between 5 and 35 degrees celcius)? Looking foward to your opinion. Thank you.

[@larryjanesky8185]

Hey thanks for the haircut suggestion! I got one! Larry

[@ryan_nicolas]

looking good Larry!

[@CyberChicChick]

+Larry Janesky I wish you HADN'T gotten your hair cut! You looked HOT with the style you had - like Jon Bon Jovi! Just go ahead and grow it on back. RJ, you look like a friggin' dork, NERD!!

[@marctannenbaum672]

Fiberglass batt insulation is tested and rated in laboratory settings. The batts are fully fluffed and in enclosed spaces (all four sides, top and bottom) with little or no air flow. The environment that the batts are tested under does not reflect how they are installed in your home. if on the attic floor, they are not fully enclosed and subject to getting dirty from "wind washing" - air movements through your ventilated attic. This dramatically reduces the effective R value of fiberglass

[@lindaraidl663]

looks like theres just a tad less fibergass from here. That could account for the 1 degree diff and the temp sensors should be at the bottom and not near the top

[@yourlocalscribe948]

5:35 looks like 20 degrees not 1 4

[@starleyshelton2245]

if both have the same r value then both should have the same heat resistance. so... there should be no difference. However it does take more in inches for batt to match blown.

[@rezaghahreman86]

I have a old house in Toronto Canada. I am wondering if I can use cellulose for wall insulation. Doesn't make rot issue during time? Any comment please?

[@mikemiller9891]

What did you come up with? I can't find Rockwool blow in anywhere...

[@Flielow]

Is all cellulose insulation the same or are there lesser quality types? Such as Cellulose insulation with out a fire resistance qualities or with out Boric Acid??

[@functionalvanconversion4284]

Great information. If you search life span cellulose has the shortest lifespan of all insulations. People also describe it become dust overtime. I try to reblow fiberglass rather than throwing it away if it doesn't have rat poo or other contaminants.

[@cameratest]

I don't understand - the R-value is a measure of how well a material insulates. Different materials may require different thicknesses or costs to achieve R13 but as long as both are R13, they should insulate equally well by definition. Isn’t this like saying a ton of bricks is heavier than a ton of feathers?

[@kennethflorek8532]

Materials with high R values get that high R by trapping tiny air spaces, the more there are and the tinier they are, the better. The controlled conditions under which R value is measured use a low difference in temperature of the two sides, keeping air circulation inside the material low. With high temperature differences, air begins to circulate through the glass fibers more and the measured R drops, much less so with packed cellulose fibers.

[@larrymaloney877]

cameratest. your confusion is understandable. R-value does not measure how well the insulation stops air infiltration. An air infiltration test shows that. Cellulose is far superior. Add that to the superior R-value and it's an easy choice.

[@carlsaberhagen628]

You're correct: "R value" is "R value," regardless of the material. However, the the "R Value" isn't the only factor (is the material properly installed, are joists exposed, etc.), unfortunately--it's just the best, shortest way the industry can market their product.

[@jerrysmith7166]

cameratest All of that shit is complete garbage and less you use foam insulation highly recommended

[@MrVocalBaby]

the problem with foam is that it goes out through the plugs

[@scoobydoo7346]

I wonder what cellulose is like for heat retention compared to rock wool.

[@georgeghali304]

I have a questions which one is better blown cellulose or blown fiberglass? There are 2 options at home depot fibergreen cellulose or Owen Corning Attic CAT fiberglass . Which one would be better for Dallas area?

[@scottsmith4145]

Interesting that in your burn test you didn't test mineral wool.... Why?

[@timkr66]

Mineral wool can resister fire better than cellulose from what I've seen.

[@dw6015]

Problem with the model is there isnt that much radiant heat concentrated on insulation in an attic so it's not an accurate representation of the conditions in an attic unless the homeowner installed heat lamps up there.

[@Casmige]

It’s just a simple test ....oh my God these scientists in the comment section just wanna over complicate and find fault with everything.....

[@stevenbourbonnais4030]

Down fall I have it in my attic and it settled under rafters and left a gap 1/4 inch and it's creating condensation and ice then when it gets hot outside it melts and creates wet newspaper

[@arnelarson2849]

In my opinion, you need to reconstruct the heat demonstration to control for the radiant heat from the lamp directly onto the top of the plexiglas. That is transferring some of the heat that the cellulose side is not. 1) Fill the fiberglas side to the top so it is equal to the cellulose side. 2) Place some foil on the top of both sides to reflect the heat from transferring through the plexiglas. 3) Place the thermometers on the bottom of each chamber to directly measure the heat transmitted THROUGH the insulation material and not the sides of the containers. Control for these factors, and your demonstration would be more accurate and more believable.

[@Deploracle]

It makes no sense unless the fiberglass is in it's installed state, not compressed down like the cellulose.

[@charlesgravespaintingcompany]

Also in that diagram, the fiberglass thermometer was much higher up (almost a full centimeter) more than the cellulose thermometer… so DUH it’ll get hotter!

[@jonathanbailey2021]

I have been a building contractor for 40 years. I won't use cellulose because it easily absorbs and holds moisture. There is always some water that can penetrate walls during extreme weather events. The wet cellulose will cause mold and wood decay which can go undetected until there is significant damage. I stay with rock wool and closed cell foam for this reason.

[@Victor-th8tb]

Hello. What's attic insulation do you recommend for Orlando, Florida?

[@zechariahhambone3841]

Rockwool just raised the price of the R15 batts from$58 to $79. And very difficult to find this stuff in the needed quantities.

[@jmar8507]

What happens if it gets wet, like from a roof leak?

[@markpitcher2357]

Is compaction a problem with blown in cellulose or fibre glass, causing lose of performance in R value.

[@creektilghman9187]

You found a very thorough step-by-step instruction and a very thorough project on Avasva.

[@CantankerousOB]

The problem is he doesn't show an R value in those tests contraptions. If you see actual blown insulation it's very light and fluffy whereas his test area it's extremely compacted. The R-value of blown insulation changes dramatically over time as the insulation settles down. The biggest benefit to blown insulation is it will fill every nook and cranny with little or no gaps between. However you'll need a much thicker layer of blown insulation to accomplish what fiberglass will. Both work extremely well, and cellulose is considerably cheaper, but to say one is better than the other is Up For Debate.

[@realtyrocks1969]

Yes he does. It said on the label R13

[@CantankerousOB]

@@realtyrocks1969 no shit it says R13. R13 is 4" thick, does it look like his thermometer is 4" from the surface where the light hits it?

[@23skido]

Do i need a vapor barrier on inside of wall? Would tyvek or typar be a good blanket to cover wall with before filling wall cavity?

[@damyonfinch8521]

Why arent the thermo sensors at the bottom. Not the middle?

[@blackfootchata86]

I wondered the same

[@babybear4524]

I dont understand why so many people choose to put in fiberglass since it heats up so fast. Why is it a big seller at Home Depot and offered by installers? For houses in the southwest would additional insulation be the first line of defense to combat hot summers or/and must you combine that with a whole house fan or attic fans? Thanks. where are you located?

[@bmo5082]

This test is kind of bogus. A black plastic bag would perform better than a triple pane window on his temperature test because he is factoring in radiant heat. When have you ever seen insulation exposed to the sun in its final application? You don’t, it’s always tucked in a wall or ceiling.

[@bobbienovak5573]

should you seal up all the little awning leaks from the inside or outside before re- adding insulation? my house is 64 yrs old & desperate need for new insulation.

[@VishalRaoOnYouTube]

My house was built in 2022 in central Texas and the insulation doesn't look like either you've shown. It looks pure white like cotton and it is very light and fluffy. Any idea what it is?

[@David_krappenshitz]

Maybe blown in fiberglass

[@mattknott4234]

blown in fiberglass just a different manufactorer

[@bluegorillacookies]

Great video....What about rodents nesting? Does the boric acid repel them? Thanks

[@yalezhang8831]

Borax sounds useful for keeping dry wood termites out of the attic, which a previous owner at my condo had. That demo showing cellulose heating up less than fiberglass seems too good to be true because it's denser with higher specific heat, which would be a problem to cool down in the evening. What I want to know is the temperature after a few hours.

[@HsingSun]

Hi, do you still use cellulose in your attic?

[@yalezhang8831]

@@HsingSun No, I never have. I'm in northern California where winters aren't that cold, so the attic has the old fiberglass insulation.

[@bmo5082]

I take some issues with his test. First and foremost, he is using a light for the heat source in the test. The light emits radiant heat, which can penetrate a translucent or transparent material. All insulation in your home is covered and protected and not directly exposed to any light. This would be like comparing the R Value of a double pane window and a half inch sheet of OSB. Obviously the sheet of osb is going to perform better at the onset because it’s going to block all the light, but the window itself has a better performance rating than OSB for obvious reasons. Additionally, fiberglass batts really aren’t used very much anymore in new construction ceilings. The typical insulation is a blow in fiberglass wool With all that said, I’m sure cellulose is a good insulation material, but personally I will stick with fiberglass as they are more common in my area.

[@joeshmoe781]

With a vapor barrier that should stop air flow. Then how does it compare? I have fiber glass in a plastic bag in my attic. What I noticed about cellulose is it compacts. 8 inches is four inches in a few years.

[@ralphinator2]

+Joe Shmoe That's why they spray wall cellulose with high pressure so that it is already compacted and can't settle.

[@joeshmoe781]

+ralphinator2 I said in an attic, not a wall. Can't compact it in an unconfined space. A very good insulation is made from rock. Probably the best. I believe it's called Rocksul.

[@larrymaloney877]

+Joe Shmoe , that's simply not true. Both blown fiberglass and blown cellulose settles. The rate cellulose settles is known and stated on every bag (by law). Contractors install the blown in depth to achieve the settled depth. Fiberglass also has a known settling rate. However it's compounded by unscrupulous installers who use high powered blowers to fluff the fiberglass. For example to get a certain depth and density with fiberglass may require fifty 30 pound bags. The contractor can add more air and fluff the fiberglass so the homeowner measures the contracted depth but didn't get the contracted density. It insulates poorly and settles way below manufacturer's claims. Fiberglass contractors prefer fiberglass because they can get the added coverage and make more money. Cellulose won't fluff like fiberglass.

[@joeshmoe781]

Don't use either. Use Roxsul. Had I known about before, I would have. It's the only stuff I would ever recommend now.

[@pipersson9258]

+Joe Shmoe / it does compact and how. Fibreglass glues and binders stick the fibres together making spaggetti bridges, there are various grades of binder, loft insulation is the cheapest binder used, cavity wall insulation uses a better binder not overly affected by wall damp. When insulation comes out of the furnace its 12 inches thick, they roll it down to various thickness's, the rolling is rather crude and imprecise, so weighing the bags is a better test of what is inside and what you have bought, like Aspirins making insulation is all profit. It used to be the bags cost more, but that may no longer be true. Well made Fibreglass beats Cellulose hands down. If Gyproc was banned for ceilings that would be a giant leap forward for mankind.

[@bigfirepop]

What I don't understand here is that for the same R rating, cellulose requires LESS material. So why are both the same size in height, length, width yet both say R13 .. Note, I am not an expert by any means

[@histubeness]

When you did the attic insulation re-do, why didn't you remove the old, dirty fiberglass batting, and just fill with cellulose? Why leave the higher fire danger batting there, underneath?

[@TrendyStone]

Fiberglass + cellulose is more efficient than JUST cellulose.

[@MikeJones-rk1un]

Handling fiberglass insulation in any way is something to be avoided.

[@africancichlids3011]

is a box spray insulation better than using a r 19 6 inch thickness ,, i need to redo my attic , when u use the spray do u still , need to add a vapour barrier , im assuming the plastic is better than the paper . , can u spray the insulation foam in a box . onto the barrier have like 6 inch thickenss then just add some r 19 insaltion fibre over the top of that or better to add the cellulose on topp of the box foam

[@CaseyBieker]

A problem with Cellulose is the in a normal 8ft wall, it settles a lot over a couple of years and the top foot or two of wall now has no insulation. We can take a thermal camera and see that in nearly all of our exterior walls, the insulation has settled leaving significant cold or hot spots.

[@cademarti1365]

Blow it in before sheet rock and they put a glue additive with it to adhere to the area it goes on. I owned a 20 year old barn that was shot inside completely even under the roof panels and it never fell off

[@CaseyBieker]

@@cademarti1365, obviously whoever built this house didn’t do that. Not sure what was available in 1978 but it’s definitely just loose in there.

[@pipersson9258]

*Fiber glass insulation is a proven performer amongst insulation products*. It provides exceptional thermal performance, moisture and mold resistance and fire protection. The two named builders below noted that fiber glass is their top choice for insulating homes. “As a builder, we are selling an energy system. And fiber glass is the answer for energy efficiency,” said Bill Decker Sr. Wayne Homes is an award-winning regional builder with a presence in Ohio, Pennsylvania, Indiana, Michigan and West Virginia - producing between 500-1200homes per year. Decker Homes builds high-end custom homes across southeast Michigan and northwest Ohio. He says Decker uses fiber glass for all it's homes.

[@jimdavidson5208]

+J.D.Roche Wrong, 1/8" of closed cell foam will outperform 2 feet of fiber glass. Fiber glass is NOT an air barrier OR moisture barrier what so ever. So how can it stop energy transfer? Answer it doesn't. The best type of insulation is closed cell foam with fire retardant.

[@pipersson9258]

+jim davidson FOAM INSULATION IS A CONFIDENCE TRICK. I met a clent who had paid a fortune for it, weeks later he scraped it with his fore-finger nail and it crumbled into little pieces like polystyrene does, naturally he rung to complain and got this message "the number you called is no longer recognised" please check and try again. Water settles into SPRAY foam, so in winter it expands and drops away from the roof, it's made with a water--mix. It get worse they charge $3000 for $300 foam and labour. Google Spray Foam Scams on Google. (And How can a MICRO-THIN 3mm layer of flimsy foam beat 24 inches of Glass Fiberglass-this alone tells me you're a scammer).

[@pipersson9258]

+Alex Blake // When used as rigid board insulation its chemistry and manufacture is similar to foam, to foamed polyurethane. As the board stiffness increases so does it's brittleness increase making handling it unstable on building sites, where rough treatment and handling is the norm. Firms who make and sell it have tons of damaged board seconds for this reason.

[@findingnimo4707]

Super vdo....vry helpful...pls tell me if i cn make cellulose foam at my home?can u tell necessary ingredients n process..plz hlp... Im from india

[@joemonroe9456]

mix detergent with packing peanuts.

[@forzaitaly1]

He liked your DIY recipe so much he mixes it with his salad too!!!

[@2awesome292]

the fiberglass batts in my attic are laid perpendicular to the joists and they are extremely dirty from the air leaks, should i fix the air leaks, remove (or just put em parallel to joists) and blow in cellulose?

[@deanbenton5098]

do both, you will address the conductive AND convective heat transfer occurring in the area

[@Mr502500]

Excellent video Doc Thanks for the information

[@CCCC-tq8yo]

The music in the background soooo annoying... 😂 rock on lol

[@bdodson5]

I agree. I had to stop watching it early just to stop that dopey music.

[@robburkhard9256]

I do fire/water restoration and have found that cellulose always breaks down and turns to half powder where fiberglass is in much better condition and its also much cleaner to pull up. Also, almost every time i go to a house in the winter and the snow is partially melted in the middle, when i eventially go up in the attic i find cellulise not fiberglass.

[@fartman2269]

Old cellulose is more fiberized than the newer cellulose, which is why it seems more dusty, it was made that way, it doesn't just break down over time.... This does not affect the performance, 6" of 40+ year old cellulose will still outperform 11" of blown fiberglass on the coldest day of the winter. If you have noticed snow melted areas on the roofs of these older houses you've mentioned, most older homes are notorious for attic bypass problems. That is when heated air from the basement flows up to the attic through chimney, and plumbing chases, to name a few of many sources.

[@johnscott2330]

I'm wanting to insulate an old schoolhouse building built in 1872. It is located in a remote wooded area. There is also a lot of moisture in the area given the structure is located on a watershed and on the edge of a creek. Does cellulose settle more than fiberglass, therefore, over time, not providing the R-value it did when first installed? Also, I battle mice. I will have to blow it into existing walls through holes. Is one insulation product better than another in being distasteful to mice? Or do mice just love it all? Thx!

[@vegafrenchies6984]

The fiberglass bay should be as full as the cellulose. Seems to be 1/2" to 1" short from the level of cellulose. You can peel some more pink fiberglass and make it balanced.

[@pdknopf]

Larry, any recommendations of installers in southern ca?

[@jacobdominguez5800]

Attic heroes

[@thcint]

You should test Hemp insulation batts and Hempcrete. You will see it outperforms everything you've shown by miles. Fireproof, waterproof, antimicrobial, antibacterial, R values, everything. Put it to the test, you will be blown away!!

[@carrieb417]

where does one buy hemp insulation?

[@thcint]

Currently, France is the best place.

[@thcint]

Here is a great way to learn all about building with Hemp www.thcint.com/thcint-blog/the-evolution-of-hempcrete-and-hemp-construction

[@bmo5082]

Man I’m glad I can get this material from France. Free shipping to USA?

[@linwoodvleegmailcom]

why is no one talking about VACUUM INSULATED PANELS ??

[@takencareofbidness]

Great video, but silly, unnecessary, distracting music in the background. We are adults... we don't need that. It doesn't enhance anything. Just one of those stupid unwritten mandates so many sheeple follow.

[@tlbfarm4473]

Agree. It should complement the narration (if used at all), not attempt to drown it out.

[@charlesgravespaintingcompany]

Why did no one mention that in 1st diagram he showed, the fiberglass thermometer was higher up, which explains why it got hot quicker… (I hate fiberglass tho, for allergy reasons)

[@MrDahkilla]

Do you sell them also as structural insulated panels ???

[@jimwhittaker5028]

I have about a 1 ft. overhang around my home. Vents under the eves are separated by about 8 ft apart. Do i need to fill the over hangs were there is no vent. Also, my roof is very low with only 2 1/2 ft of room down the center. Your thoughts on this?.

[@waynemansur2162]

Jim, my first response to "Your thoughts on this" is to sell the house. OK, my tongue is in my cheek when I say this. If your home has an "open attic" (air from the outside actively moves in and out of the attic) then you do not need to address the over hands. As to the 2.5 foot of room, it will be quite difficult for an employee to crawl around on his back and work. Good luck. Be sure to keep the attic OPEN to allow air circulation.

[@Heathh49008]

You have only shown that the cellulose is opaque. Cellulose is pushed because it's cheap. It has a better mark-up, that's why they push it so hard even though it compresses so badly, is so attractive to vermin, and has so many moisture issues.

[@dabcorn]

Fiberglass is the same crystalline structure as ASBESTOS. I put cellulose in only 150sqft more of my home as the neighbor has in his exact same 1200sqft housing project home built to federal/ state/ building codes, my electric bill is consistently $100 LESS than any of my neighbors that have fiberglass where I have cellulose.

[@Heathh49008]

dabcorn By that logic so is a diamond ring. Or salt. CRYSTALLINE JUST LIKE ASBESTOS!!!! What you have in your home doesn't matter. Do the two homes have identical floorplans/windows/structure/color, sunlight exposure, HVAC systems AND share a common thermostat? If not, then what you pay has nothing to do with your neighbor. Are you a moron? Wait... Rhetorical question.

[@dabcorn]

salt dissolves in the body and is processed by it. BARIUM is a toxic metal that can be absorbed into the body and sits unprocessed and unexpelled UNLESS it is in particular compounds, then it is not absorbed and is stable and safe and can be expelled. I am not aware of any diamond fiber products. Asbestos & similar glass, fibers ARE not dissolved nor processed by the body. The fibers accumulate, and cause abnormal cell growth in damaged areas (cancer). Mesothelioma and other lung diseases are direct results of exposure to crystalline mineral fibers such as asbestos... But any dust/ fiber, etc, even unprocessed plant fiber is not good to inhale over a long period.

[@Heathh49008]

dabcorn Barium also has fuck-all to do with fiberglass, cellulose or this conversation. As for diamond fiber products, graphite, graphene, and carbon nanotubes are all forms of carbon that could be considered fiberous and closely related to diamond. But carbon/diamond dust (abrasive process dust, mining, etc) would be a greater health threat. See also silicosis. You say "processed by the body"... actually they are removed from the lungs slowly by ciliary processes. This is often too slow, or stunted by smoking, leading to dangerous levels and possible issues such as mesothelioma. But again, you have no evidence that fiberglass is any danger in the form of insulation. Not the old stuff, or the newer "Attic cat" type that is so much like cotton candy that it doesn't even itch or produce dust during installation. You are a moron.

[@dabcorn]

Heathh49008 Yes, I may be a moron. I worked in insulation for years. However, cellulose proved to be a fine product for both installers and homeowners. It is magnitudes less energy consuming to produce. I can tell you feel strongly that fiberglass is a worthwhile insulation product. That has just not been my personal experience with it. I have though, used it for aircraft cowling. As a pool filter sand tank it has stood up very well, as have the garage doors. Anyway...we all need to follow the OSHA dust mask regulations.

[@ansis9970]

In your test, isn't light bulb acting as radiant heat source? Hence making your test more accurate representation of summer testing (to keep away Sun's heat from living space) opposed to winter testing (to keep heat trapped inside living spaces)? As an example, I am quite sure that aluminium foil would perform very well in your light bulb test because it would reflect away radiant heat. But yet people rarely (if ever) use aluminum foil alone to insulate houses for winter conditions, because foils are not not that efficient to limit heat loss due to convection. It could be that with convection heat test you will still reach the same conclusion that fiberglass is better than cellulose. However, I think it is not correct to extrapolate your test for winter conditions.

[@johnjacobjinglehimerschmid3555]

So thermal transfer isn't a problem with dense packed cellulose? By thermal transfer I mean the same sense as when thinking of a 2x??? framing how it's R-Value is much lower.

[@chrisdesimone4249]

HI, do you have a location in North New Jersey?

[@DerrickFishes]

How do they have the same r value when cellulose is that much better at insulating?

[@bigears4426]

If you have r4 fibreglass or r4 cellulose its the same and bats are easier to move for work on wiring , and you can lay bats yourself

[@ffuller83]

Mr. Larry can you refer me to such a superb service as yours in Cottondale, ALABAMA?

[@MrEvangall]

Is no one going to comment on the blown in cellulose is dense packed vs the regular fiberglass batts?

[@JM-nh8yp]

Yes, I'd like to see a pound for pound comparison with the same density and seal being formed around it. Maybe a comparison with blown in fiberglass?

[@Warcats15]

I don't understand how they are both R13 if the cellulose is performing better

[@briangc1972]

Exactly correct. If they are rated the same, then their resistance to heat transfer is the same.

[@larrymaloney877]

The cellulose stops air infiltration missed by fiberglass.

[@hotrodhog2170]

@@briangc1972 Cellulose has an R value of 3.8 per inch, fiberglass is 2.7 per inch. Insulation is lab tested at a mean temp of 70 degrees. When the temp is dropped to 0 degrees, fiberglass loses 48% of its rated R value and Cellulose gained 10%.

[@worldhello3946]

My cellulose in attic generates a tons of dust and make my room dusty. How do you pretend dust goes outside then go to your room?

[@morehp1]

You most likely have poor hvac ductwork putting the house in negative pressure

[@HsingSun]

Good question.

[@bigzee456]

What if you have fiberglass in your walls. How can you improve those areas that are inside your wall? Can cellulose be added?

[@tech29X]

Your video is deceptive; 1) You used much thicker insulation on cellulose side and 2) thermometer on fiberglass is placed slightly higher, closer to the light bulb. It is true that cellulose provides slightly higher R value per inch, but cost per 1R and weight per 1R favors fiberglass insulation. Meaning; you can achieve same insulation value of cellulose by using thicker fiberglass insulation and fiberglass would cost slightly less and weigh far less even if it's applied thicker. On the other hand cellulose reduces noise better. How much load can your ceiling hold???

[@africancichlids3011]

do they make hemp insulation yet i know they make hempcrete

[@dennisgarber]

Then, people would be burning their own houses down, on purpose, just for a few inhales, when they couldn't afford their weed . Imagine how long the installers would drag out the insulation process, and all the smoke they would make!

[@AaronCook83]

This is exactly the kind of moronic reply that is keeping hemp from being widely used.

[@maneatinghobo113]

@@dennisgarber shame on you

[@ColeB-jy3mh]

How old is the mold farm??? This is a crucial question!!!!!!!!!!!!!!

[@One1vision]

Why are they both R13 then? Would not in this example the cellulose be a higher R Value if it works so well?

[@imzjustplayin]

Because the way they test R13 fiberglass insulation is under test conditions that are favorable to fiberglass. I.e. The Fiberglass will do acceptably if you have perfect conditions but in all other scenarios it does poorly. FIberglass is shit and like most things in life, the most popular option isn't usually the best option.

[@larrymaloney877]

+One1vision , The are several primary differences between fiberglass and cellulose, One is fiberglass lets air leak past and cellulose does not. The hot air form the light leaks past eh fiberglass to the thermometer. That's what happens in yrou attic and walls and crawlspace or basement.

[@Shadowkhn]

You pretend to be an expert, and say things like hot air goes down to the thermometer. HOT AIR ALWAYS GOES UP, the only reason thermometer shows higher temeperatue for glasswool is the infrared getting through. WHICH IS IMPOSSBILE IN REAL WORLD SITUATION. If you put a paper sheet on both materials, there will be 0 difference between 2 chambers, because they have the same R value, whic considers all types of thermal conductivity. Shame on you, sir.

[@waynemansur2162]

@@Shadowkhn Yes, heat rises, Sergey, until it fills the "envelope" which is the demonstration house. Once the envelope (attic) gets a lot of heat it then filters down through the insulation, through the drywall, and into the house. In conclusion, Larry in concept spoke properly...but perhaps might use different words next time

[@tonyradca1235]

How does rock wool compare?

[@larryyates4975]

Does cellulose mildew or mold

[@publicmail2]

Cellulose has some serious short comings, like if you have a leak, and you will, fiberglass does not hold water, cellulose does. And then your ceiling is coming down. Cellulose is pushed so much because it cost the installers half the price. The only advantage is more R value per inch, and stops air movement.

[@scottbickett6991]

Sooooo its the insulation's fault if it gets wet? BTW if it gets wet it can completly DRY OUT. If it gets wet YOU HAVE A BIGGER PROBLEM!

[@ralphinator2]

+A D "The only advantage is more R value per inch, and stops air movement." Durr, and the only advantage of an umbrella is it stops rain.

[@larrymaloney877]

+A D , you trying to be funny? You say the only advantage to cellulose is a higher R value and it stops air leakage..That's exactly what excellent insulation does. If you have serious water damage, that means the drywall, the furniture and most everything else is wet and ruined. I doubt anyone will recycle the fiberglass. Insurance pays for new drywall, paint, furniture, and insulation so why not get the best? Fiberglass doesn't hold water because it's a solid core material...which is why it has a poor R-value...It will grow mold. It will cause cancer. It will melt & the paper coating will burn and the melted fiberglass will give off gasses. As it burn =s out fo each wall cavity the fire spreads to the ceiling and attic. I would not install fiberglass if it were FREE!.

[@scottbickett6991]

+A D "HIGHER R value and stops air movement" ..WHAT MORE DO YOU WANT!! If FG doesnt "hold water" THEN WHERE DOES IT GO? it has to GO somewhere! AND if you get a lot of water in your attic/ cieling YOU HAVE BIGGER PROBLEMS than the insulation!! sheesh.

[@ralphinator2]

scott bickett Don't forget "it cost the installers half the price". So besides being cheaper, working better, and being more ecological, no advantages really.

[@bobsilvern4909]

The temperature test is bogus! It is deceptively designed to measure the materials' ability to block infrared and visible radiation from the bulb rather than thermal conductivity which is an entirely different property. A more fair test would require placing an opaque surface, e.g. a piece of drywall, on top of the insulation to block the radiation and actually measure the conduction which is all we are concerned with in any real-world setting. Another tip-off: Both materials are ambiguously labelled R-13. R value has a meaning only when specified for a product with a defined thickness. Assuming the meaning of the labels was that each side, in the tested thickness, provides an insulation value of R-13, then both must conduct the same amount of heat by definition. They cannot differ in any fair test of thermal conduction. I was planning to insulate my home with cellulose, but after seeing this slimy act of deception I will reconsider that decision.

[@johnsmith9782]

Bob Silvern Yes, this is classic hoodwinking here with that test, from the obviously observed issues to a host of other unseen factors. It fools some folk all the time, and these tests are designed by manufacturers and paid promoters, and you would have to be pretty dull not to see through it. We live in a 'anything for a buck' culture.

[@stephenvonwaldner9374]

Ki I

[@ralphinator2]

+Bob Silvern After they just showed you how well it works, you decide not to use it? No, thermal conduction is not all you need to think about in the real world. Convection air current travels right through fiberglass, and the siding of the house radiates heat just like that lightbulb does. Unless you are planning to wrap your house in aluminum foil, you also need to block radiation heat transfer.

[@bobsilvern4909]

ralphinator2 The convective properties for cellulose compared to fiberglass may or may not be better. I do not know and the experiment performed in the video does not attempt to measure this. People who have large openings in their walls through which there is notable airflow should probably just caulk those cracks rather than rely on in-wall insulation to block the air flow. As for your claim that "the siding of the house radiates heat just like that light bulb does", you are mistaken. The total radiated energy of an object is proportional to its absolute temperature raised to the fourth power. The incandescent light bulb temperature is about 3000K, compared to a warm wall at let's say 130F or 328K. The radiation from the wall compared to the bulb is therefore in the order of (328K/3000K)^4, or about 0.014%. This is why the bulb radiates blinding light and scalding heat, and the wall does not. To summarize, in real world applications, the conduction of an in-wall insulation material is by far the most important property compared to radiation or convection. The "experiment" in the video is grotesquely flawed in that while it claims to measure the conduction of the material, by directly irradiating the material with an incandescent light bulb (a 3000K visible and infra-red emitter), it is primarily measuring the material's ability to block transmission of that radiation rather than its conductive properties. Had they actually measured the conductive properties, they would have found them to be identical because both were specified as R-13. I don't have a strong preference for one type of insulation over the other, but I would certainly avoid doing business with Dr. Energy Saver after seeing how they attempt to deceive potential customers with a clearly bogus demonstration.

[@ralphinator2]

Bob Silvern Cellulose is very good at stopping convection while wind blows right through fiberglass. It can be used for air filters. Convection transfers heat from the outer wall to the inner wall. You are right that there is an exponential difference in radiation, but the square footage of a wall goes a long way to making it matter. If you stand near a stone or brick wall at night, you can feel the radiation coming off it.

[@FakeNewsHunter]

4:48 the left side can hardly be filled up. And nobody knows if it is filled. I guess there will be many undiscovered gaps where no cellulose does its isolation job, because its simply not there. .

[@giuseppepippoizzo6506]

Excellent video explaining , accurate information. Great information

[@tishvillalobos3255]

Hi can you tell me if this is good for cold climate like Alaska. I want to build a small cabin can you advise

[@lulolee5325]

It's illegal to build any "cabin" on your own! Your contractor will know all the requirements, your business only to take mortgage in a bank.

[@ryandecarlo]

But is it good for IMPACT NOISE?

[@chrisdixonstudios]

It also very clearly shows much less Fiberglass insulation over top of thermometer less dense than cellulose (light penetration). You forgot to mention that fiberglass Far outlasts cellulose like 100 years vs 50. It is very impressive however how well cellulose insulates and is fire retardant, cool! Cellulose also fluffs back better than fiberglass if compressed. Probably most important is the cost of cellulose is only about 30% cost of fiberglass, so boom you win!

[@zilfondel]

Guy knows his stuff. As an architect, i found this video incredibly helpful. It also matches what i learned studying building science. Thanks!

[@pollyanna163]

Turn the friggin music off. What the use???

[@richardschank7624]

Can this be blown into plaster walls?

[@jwisdomful]

Is cellulose also the healthiest Insulation for the house? My son has some breathing problems and I want to make our house healthier.

[@vbezbradica]

Few words. When comparing cellulose and fiber glass insulation as a insulation materials is good to say that first of all he didn't put same thicknesses. Ok it is with same R value, but why you didn't compare thicknesses with same peformance regarding thermal stability? . Second thing which has to be counting on is price of materials. It is fact that cellulose has better heat capacity, and higher density which refers to heat wave conduction in summer days through construction, but for some fiberglass thicknesses ( higher than cellulose ) ,with better thermal conductivity you can get same results (in living comfort), but with lower price. ( I would like to mark winter time, where you have much bigger energy saving with fiberglass for less money) Good approach would be to compare cellulose and fiberglass insulation with same results for thermal stability of construction , and to see what are the costs? Also you have to compare installation costs, and whole costs in life cycle of material. If the roof or wall is ventilated (what is recommended) , than influence of the heat wave during the summer days is not so important. Only if you consider whole this things you can talk about quality of some material for some application. Such approach ( in video above), gives you one side of the story, and other one seems is good not to be revealed :-) Cheers

[@hotrodhog2170]

All insulation is lab tested at the mean temp of 70 degrees. When the temp is dropped to 0 degrees, fiberglas loses 48% of its R value where Cellulose gained 10%. So in the winter when you need that good R value, the R-38 in your attic is now an R-16. Which do you prefer?

[@ecospider5]

What about rockwool vs cellulose.

[@kathleenscherban7433]

What kind of fire retardant chemical is used. This may be as dangerous as spray foam. Please advise.

[@larrymaloney877]

+Kathleen Scherban , boric acid. It's also used for eye medication.

[@laurinn607]

How can we SEAL l the cellulose PARTICLES in the insulation because I feel it gets blown into our inside air inside our home and causes allegies.

[@larrymaloney877]

If you are allergic to newspapers don't use cellulose. The fire-retardant is boric acid, routinely used in eye medication. What allergy are you imagining?

[@hotrodder62]

cellulose is a totally ORGANIC product. I have been blowing it for over 28 yrs and have NEVER had anyone claim "allergies" how so do you think its "getting blown into our inside air"? what it the cataylist for "making it move"??

[@ambroulard]

Here’s a question I wish somebody who knows more than me would answer,, I’ve seen insulation put up directly between the roof rafters, ( I think with a plastic barrier covering it as well) and of course I’ve seen it put in either as batts above the ceiling or blown in,, My question is what determines which system you should use? Or should you possibly do Both even? Any help on this would be greatly appreciated!!!

[@kiptonm]

It depends on what you are trying to do and where you live. If you want to build a room, then you put the insulation against the roof. In most cases people vent the attic to let extra heat escape or to keep ice from forming on the roof. In very hot climates, you want some space between the roof and somthing like a solar blanket to keep the roof cooler making asphalt shingles last longer. The bottom line, solar blanket on rafters. Lots of insulation on attic floor.

[@Ddorini]

Hi! I'm so interested in these cellulose materials! But, as you know cellulose are combustible! Do any one knows about how wcan avoid from easily burning out? Like adding flame resisting materials in it?

[@Deploracle]

Did you watch the video?

[@dave6799]

any contractor recommendations in lake county IL?

[@TrogdorBurnin8or]

You explain and test that R13 of cellulose is different from R13 of fiberglass, but you never mention why. R-values are objective metrics. You need to explain what's going on here in order to explain why one is better than the other; According to the information you have provided us, your result is nonsensical.

[@lifeisgood070]

what about in the humid south?