Joe is amazing, every time he speaks it's supremely educational and entertaining!

Thanks for watching!

The guy he was answering seemed to get a little combative. Joe was right though

It's also an extremely small cross-section. So even though the SS screws are 15X(?) more heat-conductive than wood, they have 100X less cross-sectional area. So the SS screw (or even plain steel screws, 30X(?) more conductive than wood) is a net win for reducing thermal-bridging (vs a wood stud/furring strip).

He doesn't really like SIPs, specifically for roof assemblies. At 56:30 he is responding to a question about SIPs (the question is inaudible...).

@@fredygump5578 I wonder if the SIPs he made were EPS(styrofoam)? While I have installed those I don't care for them for many reasons mostly vapor migration. The SIPs I use are Closed Cell Polyurethane and I use Polyurethane Expanded Foam between each panel. I made a video you might like called "A House that will not Burn"

@@ModernMountainLiving His were probably EPS, statistically speaking. I've seen a company that makes polyurethane foam panels, but I've only come across the one. He likes SIPs in theory. His objection is that in practice, it is too difficult to apply sealant properly and get a perfect seal between panels every time. To mitigate the risk, he suggests a vented cold roof over the top of the SIP...fur it out w/ 2x2. Then if/when moisture gets through a seam, it can dry without causing any damage. (In other lectures he talks about investigating SIP failures, so he knows what can go wrong.) Regardless of the SIP panel system, I'm sure he'd say the same thing...include an outside moisture control layer with an air gap, both for walls and roof. He also says he doesn't think of SIPs as being very high performance. For him, high performance is R45+ walls, and more in the roof.

@@fredygump5578Not out yet but I have a vid of our SIPs installation posting soon. My current build is with ECO SIPs w r-42 walls and R54 Roof. Other Closed Cell Companies are Ray Core, and Thermospan. ECO has a cam system I really like. I have reservation about stacking layers of vapor barrier together. If there is ANY vapor Migration(likely) between layers without ventilation any organic matter(sheathing) will rot. This has been a study of mine for a long time. Layers trap moisture. My current build during construction was heated with a single 1500 watt space heater. The performance was 57F inside with -20F outside at 9000' in the Rockies. I'll include pic in the Video. Good Talk Thanks.

@@ModernMountainLiving RayCore is the one I was thinking of. But I'm not very excited about SIPs. I'd consider them for my garage/ shop, but that's about it. Possibly Insulated steel panels, which are essentially the same thing..

actually the did make energy efficient mobile homes in the 80's, but those models were much more expensive. if you can afford a more expensive mobile home you can afford a home. interestingly enough, and as you have already guessed: those mobile homes ate roofs because of moisture problems.

my understanding was that he was saying you need Typar etc on the outside of the sheathing or he mentioned ZIP system in his preferred example. I thought he was saying that the interior vapour barrier was not necessary if the exterior insulation was over 2 inches. That way the interior insulation could dry if necessary.

I thought he was referring to the interior vapour barrier rather than the membrane on the sheathing as being something you could avoid if you have thick enough exterior insulation..

There are plenty of vapor permeable moisture/air barriers that can avoid the issues caused by a proper vapor barrier.

It's not

the jokes are good, too good.

Didn't he give a talk that references a book of old green and energy efficient building practices based on climate?

I don't think the principles have changed. It's just that the building industry and the home owner either don't hear or don't pay attention. Builders and manufacturers are super conservative (aka stuck in their ways).

I wondered the same thing - mostly in terms of shear strength of the wall - with sheathing only at the corners. Thinking about it, I think the exterior insulation board with cladding over it ought to keep out any solid objects. I'll trust the engineers on shear strength, if that's what they say...

!!!!!!! LOL

Yup, both are flexible enough to compensate.

Snow insulating the roof does not cause ice dams. Heat from inside the house warming the roof and melting the snow causes ice dams. Only static air is an insulator, moving air such as in a vented roof will carry heat away but will not insulate.

@@percyfaith11 If the roof is metal won't the snow slide right off if the underside is heated up? Or will I still get ice dams?

@@NoName-ml5yk Sure it would, if your objective was to waste tons of money and energy.

@@percyfaith11 I would only heat the attic long enough to slide the 4+ feet of snow off the roof so it doesn't collapse. Maybe 2 or 3x in a year tops. Using the whole house fan system I'm going to install. With heat from the wood stove. So less than $1 in gasoline to process the wood. Do you know from experience that I won't get ice dams using this method or just an educated guess? Locals give me mixed opinions.

@@NoName-ml5yk the edge of your roof, over the eaves won't be heated. That's where the water that will be running down from your heated roof will freeze. This will create ice dams unless you put heating wires along eaves. Much better is to insulate and air seal your attic so well that the roof won't be heated at all. That way you'll never have to worry about ice dams. Any architect or engineer will be able to tell you the specs you need to build your roof to so it won't collapse under four feet of snow. I think a metal roof will probably be slippery enough that snow will slide off it without heating it. The idea of heating your roof really sounds wacky.

Us Americans apparently need a century to catch up!

I think a direct comparison is a bit unfair. The biggest difference, I think, is that Americans are used to having seemingly unlimited cheap energy. Because energy is cheap, it has been difficult to convince people to improve their houses. Builders in particular love to say better efficiency isn't worth it monetarily, and with current energy prices, they are correct. These builders typically don't want to change their ways or learn new ways of doing things. But there are a growing number of people who feel that we have a responsibility to reduce energy use, regardless of cost.

​@@fredygump5578 I agree with most of what you say. US i big, and climate differs a lot between areas. But the strong preference for always placing vapor control layer on the outside baffles me. Same with shingles on the room and only having that one layer to rely on. A disaster waiting to happen if you ever get snow on the roof, and a risk in any climate if the nails start to rust.

@@craigsandifer1573 Interesting figures, my house uses about 12000kWh per year, built in the late 60's about 160 m^2, heated by thermal heatpump last 10 years. A new house in southern Sweden are allowed to use 55kWh/m^2 per year for heating/cooling. In northen it is 130. So for a 100m^2 house that translates to 5500 and 13000 kWh.

It gives OSB too much credit, but pretty much.

And looks like Richard Dawkins

I own a Queen Anne from 1895 in New Orleans. We have similar construction. For all the same reasons you mention, I have been VERY hesitant to use spray foam on any exterior walls. I would be very cautious of doing so. During renovations, I had access to a few sections of exterior wall from the inside. When closing the walls back in, I layered from inside out using the following materials starting against the cypress wood siding: Delta-Dry rainscreen (a German product), Tyvex's commerical moisture barrier product, and finally Rockwool batts (made from lava rock). Don't use fiberglass that will MOLD in your old house! If there was a way to share my contact information with you private, I would send you some photos. If you know how, feel free to reach out to me. Good luck! P.S. Watch Matt Risinger on here. He does an episode highlighting a woman contractor who builds a very similar wall using the same products I used in an application nearly identical to yours.

Jim Hansen Yes, but if there is a Fire, the Fire Dept. all get stoned trying to put it out, the building burns down anyway, so you’ll have a chance to build it better the 2nd time. ; )

@@JohnR84 not if you are still high!

Do the walls have vinyl wallpaper?

@Leon Milner LOL yes that is what I said ... serious.. or just no sense of humor

Seems more of a bunch of 'green' architects types who design boring/ugly Passive House projects -

We engineers have a sense of humor. He is right about the "efficiency gene" some call it perfectionism. But many do not understand that even in engineering truth can be well hated because along with that "efficiency gene" we have the "I am right even when wrong gene". When you tell an engineer something they don't believe in you get resistance and you are not funny. The ones that laugh get it and will tend to be better engineers while the ones that don't are a problem.

Try not take it too seriously, he's just using levity as a mechanism to connect with the audience and break up the information dump to make it more digestable thereby make the subject less intimidating. Remember this was filmed live for an audience. It's all well and good watching the performance afterwards as a video and being able to rewind, but having those small digressions helps give the audience time to understand these concept as the show goes on. As for the content of the digressions, they didn't seem very angry and negative to me, not in any genuine manner.

@@Shryquill point taken. Maybe it’s just brand-of-humor.

During the Las Vegas / New Orleans segment he explained that big companies have a formula that they build by all over the world, regardless of climate conditions. They keep the construction costs down and don't have to operate them. Even today, builders and their clients pass the increased maintenance and operating costs on to the consumer, or renter, or owner, so they don't care.