Insulation R Value - It's Not What You Think

Steve Maxwell offers a screencast explaining why buildings with similar R values can show such wide differences in energy performance. To learn more from Steve, visit www.stevemaxwe....
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#insulation #insulationnation #insulationfoam #insulationinstallation #insulationsucks #insulationremoval #insulationlife #renovation #Renovations #renovationhouse #renovationproject #renovationideas #renovationlife #RenovationContractor #renovationwork #renovationspecialists #renovationinspiration #renovationprogress #renovationworks #renovationtips #renovationplanning #renovationproblems #renovationonabudget #renovationtime

[@MrTaylorcraft]

Your pep level was fine. Some people just want to bring people down and cause problems. The information was second to none. Thank You!

[@christianclark2763]

Agreed. He's talking about insulation not the new Corvette.

[@syed1559]

You have cleared my concepts around effectiveness of just pure R value. Thanks a lot.

[@TsetsiStoyanova]

Very well put together video

[@ConcordCarpenter]

Well done Steve

[@Normambo]

That was a worthwhile watch. Good basic info that goes beyond the all omnipresent deceptive R-Value umbrella.

[@Supernaut2000]

This is a great and easy to understand video that captures the key elements and significant advantages of SIPs. Thanks for putting this together!

Some SIPS have studs in them, some don't. Buy the kind with no studs, such as Premier SIPs.

[@christianclark2763]

My coworkers and I are putting a new floor system in a house built on piles and we're putting foam in the joists right now. We were just talking about this today and this video is amazing. Thanks a lot

[@BrokenTVink]

R value stands for thermal resistance. and it's an expression for how many hours it takes 1 btu to transfer through 1 square foot of material with 1°F temperature difference. So R20 means 20 hours for 1 btu transfer through 1 square foot of material and different materials are used to build a wall so you add them up. Then you have K and U factors but that's too much for one comment.

[@MrBrianDuga]

Granted, but be sure to read an article called “Foam Fails.” It talks about how foam shrinks and fails over time. So if rigid is used, it might be better to install 2 layers of 2” with offset joints to account for widening gaps over time.

[@Scorpiomaj27889]

I'd be interested to know how Roxul/Rockwool ties into this. Something about the weight and seemingly higher density of rockwool vs fiberglass makes me feel like it's doing more to insulate than it seems.

[@bgregg55]

so, what you're saying is we really need a whole new system of rating the various insulation products. i'm all for that.

[@robertocorradi6318]

Really Excellent , clear and precise explanation . . . Very interesting . Thank you very much .

[@free_at_last8141]

Very interesting. Thank you for creating the video and explaining.

[@Futurestone]

Well done. This is why Insulated Concrete Forms are the best wall system. Adding thermal mass to the mix.

[@nc3826]

Well done. This is why CC/ACC/Aircrete is the best wall system. Adding thermal mass to the mix...And it eliminates the use of toxic foam insulation... The ICF insulation on the inside wall of the building eliminates most its thermal mass from the concrete anyway... Not to mention the health concerns....And while ICF finally just caught on in the USA, decades behind the rest of the world. That has rejected it for better options... The truth is there is one best system and it certainly not ICF...

[@jl9678]

Imagine trying to move a window in an icf house $$$$

[@kennethflorek8532]

The way I heard this explained, while comparing fiberglass to cellulose, is that the R spec is officially determined at a modest temperature differential, more or less taking for granted that R does not depend on the differential. But resistance to heat transfer is due to tiny trapped air spaces, and air moves fairly readily in fiberglass from space to space, if there is any temperature or pressure differential. Fiberglass, coated with something sticky, is often used as an air filter. The official R number overates fiberglass drastically as the temperature difference increases, because the large difference causes the air to move more in fiberglass. The fiberglass manufacturers don't bring this up at all. Whether the big, colorful fiberglass guy has ever done anything to mitigate this fault with fiberglass, as would seem logical, I don't know.

[@lyndonthan4350]

There are issues not discussed here. The enviro impacts of foam are significant, compared to NATURAL fiber based insulations. Foams are in general very poor choices for health, as well as fire resistance. Sips panels are sometimes not a reliable structural element in buildings, and the rate of convection in fibrous insulations varies significantly. There are many types and densities of fibrous insulations, fibreglass, mineral wools, wood fiberboards, dense-packed or blown-in cellulose, etc. It is true that foams are pretty impervious to air and usually to moisture, but there are also studies that show some foams especially lose their R-values at low temperatures as well. I believe it is Polyiso that that drops in R-value dramatically below -15C. Finally, foams cost about 10 times (or more) as much for every square-inch R, than cellulose, fibreglass, wood fiberboard, etc. Keep in mind, foams are simply gas encapsulated in plastic bubbles. If that gas is air, fine. But if that gas is something else, there will always be a net force on that gas to diffuse out of the foam. I have to wonder what the life expectancy of foam insulations are in the various temperature regimes, and how their performance holds up over time. And personally, I'd rather insulate with fibrous materials than foams, and address the convection issue by using a denser fibrous insulation. The regular fibreglass insulation is very very loose, and does have a lot of air in it.

[@mortenlund1418]

I am with you all the way.

[@gabriellabos6626]

Thank you very much for this clear video. Sometimes I also miss an explanation about fire resistance and sound insulation values. I would love and other video from you with more :)

[@nobreighner]

Don't forget the initial framing factor that can be significant. And later, any wet fiberglass clumps up and becomes a thermal conductor, also creating bigger convection cells.

[@trevor44ish]

That's a great explanation. Thank you

[@johnellis7614]

The optimum vapor barrier is a plastic sheet on the outside of all drywall, the insulated cavities encapsulated on all sides by a plastic sheet and with the top one inch of each cavities facing the sheathing left open to keep the insulation dehydrated.

[@dienekes4364]

Very informative! Thank you!!!

[@mortenlund1418]

Insulation like Glasswool and Rockwool are untoxic and fireproof. Further more in a wooden construction it is prefereable to have some kind of moist transfer from the warmer side to the colder side. Convection. How long does this foam last? Rockwool last at least 40 years.

[@ElvargsBane]

if you are using SIPs then isn't the fiber based cavity also containing framing that may result in thermal bridging? So even the Rvalue Conduction isn't comprehensive as wherever a board breaks up the fiber based coverage.

[@roberttomsiii3728]

Could you post your Source material link in the video description please

[@rogerwelyki1370]

Finally , a smart man shows the truth about heat transfer

[@phillipjohnson7583]

Nice video...worthwhile real world info.

[@CommentsAllowed]

Think that may not be mold in the fiberglass insulation. There are a lot of myths out there about mold, and what is and isn't. My understanding is that we say something is mold when it isn't, just because of discoloration. Most typically, we say "Black Mold". I recently pulled out fiberglass insulation from a wall and it had a very similar black "mold" like look to it as shown in your picture. However, it was most likely just dust/dirt/debris. The insulation was near the cold air return locations. With how the cold air returns were designed, they are not sealed off and can pull air from the wall cavities themselves. This pulled dirt and grime into/through the fiberglass insulation, like it was a filter.

[@zmosoly1]

thanks for sharing .information of great value

[@mohammadowais001]

Very nice explanation...

[@betazoid100]

I think you are making an error in stating that fiber insulation supports convective air currents; indeed, the very mechanism of heat resistance occurs by virtue of the tortuous paths created by the fibers which minimizes such currents (i.e., insulation is designed to suppress these currents which is why even steel wool, in spite of the high thermal conductivity of the individual fibers, insulates because the dominant mode of heat transfer is convective).

[@badairbnbguests.robert6516]

GREAT PRESENTATION... but fiberglass batts and rigid foam insulation are not the only options for insulation. Please also consider and promote - dense pack cellulose insulation. It’s a recycled product, and is natural (made of paper) and is a way to sequester carbon in your home (since the paper is made from trees, and trees absorb CO2)

[@mattodrums]

when insulating existing walls, would dense-packed cellulose offer convection resistance benefits? In my case, heat gain is the largest concern (SoCal temps... sorry Saskatoon)

[@JoshGreisen]

Great video, thank for sharing!

[@libertyrich555]

A complete new standard should be used for modern homes. If I use R factors for heat loss, open cell is 3.5 per inch while fiberglass can be 4, and we all know how poorly fiberglass is. So, we at least need a program which shows fiberglass and foam exposed to 20 mph winds @ zero degrees for 24 hours and use that factor for heat loss/gain design, it would be much better than the rubbish we are expected to do today with Manual J. So sick of Ashrae and ACCA dragging their tails on this important topic. Anyone use a higher rating to compensate for the fake usage of R factors so their totals are more realistic? What I've currently have done is basically lowered my infiltration to almost zero which helps. but radiation is still an issue.

[@monkeeyme]

Thanks good info. So what you think is better: Radiant Barrier or Fiberglass Insulation?

[@davebrittain9216]

I have been telling this to people for years and they still use fiberglass insulation. A point that I find where closed cell foam insulation really shines is in a finished basement. I have been in two year old million dollar houses where they got the basement finished using fiberglass when built and they have terrible smell of mold/mildew. I think using foam in a basement should be against code!

[@kjbaert]

so if not using spray foam how do you seal gaps between the foam and the wooden studs? such as an acoustic sealant or tape?

[@ReflectedMiles]

What isn't mentioned here is what happened when hundreds of homes in Alaska were then built with SIPS to accord with this principle. Whoops. The same problem turned up in all kinds of other places as well. Thermal control doesn't matter much if your air and moisture control aren't correct, and so when SIPS didn't control those either, they created even worse problems than having a poor R-value.

[@baileylineroad]

Hi There! The air tightness of SIPs (or any other tight, modern building system) must always be accompanied by top-drawer practices in other areas of construction, too. That's why every type of tight house requires mechanical ventilation. That's an unavoidable part of energy efficient construction. I don't know the details of the situation you refer to in Alaska, but if internal moisture levels were too high, then heat recovery ventilators are the answer. They work every time. You get fresh air and you save more than 75% of the heat from the outgoing stale air stream. Thanks for watching and commenting. Steve

[@ReflectedMiles]

***** Actually, the problem was internal to the foam panels when they were used for the roofing structure. The airflow networks within the panels, just like in fiber insulation, allowed warm moisture to rise to the highest point and began to mold and rot out the top 18" of the panels. Homeowners had mushrooms growing out from under their shingles. Foam panels used in that manner require a vapor-open top and vented over-roof to be safe--an expense few homeowners are interested in paying for.

[@baileylineroad]

Ah, yes. Thanks for clarifying. 6-mil poly on the inside of the panels would have stopped that condensation. Normally this isn't needed with SIPs, but perhaps with the long periods of high temperature differential it's required in Alaska. Take care, Steve

[@JGLASRUD]

Reflected Miles could it be they were open cell foam sips?

[@danasaylor2017]

Reflected Miles and

[@shawnbarrington2360]

I own a home in the south I have no insulation and wood panels. What would be best insulation to use and should I replace panels with sheetrock

[@deerhunter7482]

Closed cell foam

[@azadnazzarali350]

can u tell me how to improve a external wall u value of 0.28 by 10 per cent

[@azadnazzarali350]

or can u post a video on this topic because I am struggling

[@CommentsAllowed]

Does anyone else see the :( frown face on the fiberglass insulation? Once you see it, you can't un-see it. lol

[@mikecampanella1990]

Hey Steve, I know this is an older video now but I'm hoping you respond. With a typical air barrier like tyvek, and then rigid closed cell foam on the exterior of a home for a retrofit, would that fix this issue and make for a much more efficient building? Also, how would a double stud wall do in something like this as long as there is a tight outer shell?

[@baileylineroad]

Hi Mike! Glad to help . . . One of the best things you can do in a retrofit situation is add rigid sheets of foam on the outside of a building. This boosts effective insulation action, it reduces thermal bridging, and it makes stud wall cavities warmer for a given outdoor temperature. This greatly lessens the chances for condensation to occur inside wall cavities near areas with a less than perfect vapour barrier. Double wall construction boosts the energy efficiency of a building, but you don't get the effectiveness of foam. Drop by my website baileylineroad.com for a visit sometime. You'll find lots of stuff there, including tool giveaways, articles and the chance to ask me questions. Bye for now and thanks for watching, Mike! Steve

[@mikecampanella1990]

Steve Maxwell that's great to know, thanks alot Steve! I'll check out your website for sure. I've watched many of your videos on here and I've become a big fan. Thanks again!

[@baileylineroad]

My pleasure, Mike! I'm glad to be of service. What sort of renovation do you have planned? Where do you live? Bye for now, Steve

[@mikecampanella1990]

Steve Maxwell Well, I've got a full remodel on my 1950s cape style home in climate zone 5 in the states. I've gutted it down to framing and air sealed every cavity bay with great stuff and their gun. Then stuffed each bay with roxul r15 batts. The only thing about exterior insulation being added is the house has no overhangs or soffits and creates a much larger job. I recently put a full length dormer on the backside of the upstairs which will allow me to vent that roof. I'm filling the bay's with r45 of roxul, and then having 2 layers of 2" poly iso taped and sealed to the underside of the rafters for a vented r71 roof assembly. Xps foam on the basement interior walls and rim joist, with roxul in front of it as well. If you think I can improve any of this, please let me know!

[@baynerw]

Awesome video! I have seen the rather gross results of fiber or cellular insulation and honestly, it is a waste of time and money. Rodents love it and certain molds can be dangerous to young respiratory systems. Faced foam is the way to go as far as I am concerned but I would like to hear any negatives to foam (besides expense) anyone might have to offer.

Foams for insulation come in two different plastics. EPS is the stuff you can buy hot coffee in, and obviously, it is harmless and impervious to water. The other kind, not so much.

[@alexlindekugel8727]

foam works great aslong as the wall assembly stays dry. other wize rot runs rampent. and also major fire hazard. beyond that i" properly design" system works great.

[@joeshmoe781]

Were both homes orientated the same to the sun?

[@baileylineroad]

Joe Shmoe Hi Joe! Thanks a great question, and yes, both homes were side-by-side in the same subdivision, both facing the same way. Drop by for a visit sometime at stevemaxwell.ca. I have lots more information, video and tool giveaways there. Bye for now, Joe. And thanks for watching! Steve

[@rogerwelyki1370]

I am in a related field I would welcome you to see something really cool that shows your principles in dramatic fashion I am interested in that Brock U study The term R value is used very loosely and never truly explained to the average person I would like to ask you for email contact to talk more about this

[@kiefk3065]

www.thermapan.com/pdf/Thermapan-SideBySideWhitePaper.pdf

[@rovertrobert3180]

Is a house full of fat people warmer than one with skinny people?

[@williamglanton2625]

F

[@johnellis7614]

I am building a cabin with 16 different types of insulations and will closely monitor how they perform in relationship to each other. For we need proof and with proof, we need class action law suits that will drive the fiberglass insulation industry bankrupt. Just try and discover the pounds per cubic feet (pcf) of any fiberglass batt, talk about conspiracy. Fiberglass attic: R-2.8/in. . 5 pcf Fiberglass wall: R-4 1.0 pcf Cellulose attic: R-3.8 1.5 pcf Cellulose wall: R-3.7 3.5 pcf Cotton: R-3 Straw: R-2.7 Pine needles: R-2.6 Hay: R - 2.5 Sawdust: R-2.2

[@user-hu1um2xk5h]

This is total B.S. if you really wanted to teach something simply ask what type of house a person has and what state they live in and tell them what insulation and how much/thickness to you. If you can't do that then you don't know anything more than somebody who knows nothing and therefore you shouldn't even begin to attempt to even think about teaching anything to anyone. Instead you should be spending your learning trying to learn.

[@litsakoylitsa4167]

The whole video is correct because I have a glass wool insulation which has the yellow fiber wool inside a double brick wall, which also has a sliding door in it in one its walls. The more the temperature goes down, the more absent is the insulation. And because the roof is a 6 inch exposed to weather concrete floor (with inside plaster and paint) and no other insulation, all the heat goes out immediately no matter how much heat I build inside when the temperature outside goes bellow 71F. The distance from the sun at 3:26 is a false belief. Earth is flat (eric dubay)

[@cevan4156]

Litsa Koylitsa ah no. No it's not

[@leepeace437]

Litsa Koylitsa not a sheep

[@TheTerry2good]

add some pep to the lesson I fell asleep