99% of Homes DON’T have this detail.. Worth it?

[@mxb_se]

You guys are going all out! Super smart to prevent possible issues, rather than fix them later. Well done.

[@MasonDixonAcres]

That's the hope!

[@alishatruman]

WOW sooo much knowledge and FIRE S..... what? WHAT!? AMAZING!

[@Ann-h6l4s]

Great job guys, your doing an awesome job.

[@CMCraftsman]

I used Rockwool and Majrex in my house. Lots of work to detail it well but worth it. It is important to note that if you already have heat in the house going or you’re using a kerosene heater, do not insulate the house and then install the Majrex. Do one wall at a time and complete the process. I found that the back of my zip was wet the next morning after insulating a wall and not getting to seal it up with the Majrex before leaving for the night.

[@MasonDixonAcres]

Good tip! We just had the radiant on in the garage to keep it around 45-50. No significant moisture generators

[@simfoo]

That Rissan tape is no joke. I used it to tape the bottom of our outside walls to the concrete base floor, using a primer on the concrete. It's so incredibly sticky, nothing I've used before even comes close.

[@MasonDixonAcres]

It really is. I have no idea what they use for adhesive but it's gummy and extremely tacky with almost no pressure. Apply pressure and it's never moving

[@arsalan101]

Always happy to see you guys progress

[@jonathanfriedrich2941]

Good work!. Majrex 200 is pretty much the best thing you can get. Using that here in germany too. Fentrim is also a perfect choice. If needed, you can trim the chims off to make it fit better. Eletrical boxes are an issue, at least here, boxes exist that do have entries covered with thin rubber where you can pinch through your cables and are in most cases automatically sealed then. Not sure if they exist in the US

[@generessler6282]

Nice. Yeah you're right to be concerned _how_ the house is sealed. The seal keeps any bad stuff inside as well as the temp-controlled air you want. Mold wasn't really a thing back when houses were drafty.

[@jacob1bk]

Cold air leakage causes cold condensing surfaces. Warm humid air leakage causes condensation to form on those cold surfaces. Condensation causes mold to grow. It takes energy to dry a wet surface not drafts. What's changed is the amount of insulation we are packing into the walls to prevent heat loss. In turn this reduces the amount of energy available to dry the walls. In my opinion, if you are going to build with light frame construction, your best option is to use enough continuous exterior insulation to keep the wood materials above dewpoint, airseal at the exterior to keep cold air out of the wall, and use a vapor control membrane on the interior to slow the movement of moisture and allow drying. And, if you don't use an energy recovery ventilation system in these homes you are basically living in a filthy fish tank and don't know it.

[@2ndmileproductions]

“Bad stuff” is handled by the ERV. The real bad stuff is when your house is able to “breathe” in an uncontrolled manner.

[@eugenec-k9v]

Are you installing strapping on the ceilings and walls to allow for a service cavity between the majrex and drywall or installing drywall directly against the majrex? Also any plans for how to deal with patching old nail or other holes post construction when things move around in the drywall that penetrate the majrex? Haven't seen any good plan for that from anybody.

[@MasonDixonAcres]

Couldn't do the service cavity unfortunately, I explain why in the next video. We don't plan to put any fasteners in exterior walls that aren't going through Twinet and into framing, and staying in place. You have to be mindful of it for sure, but if you really wanted to put a big nail or drywall anchor in and then remove it you could carefully cut out a small square of drywall around the hole, tape the hole with Rissan, then patch in a new piece without fasteners

[@paulmarshall7328]

I'm confused. Is it wicking to the interior?

[@MasonDixonAcres]

The membrane allows drying towards the interior of the house, in the case moisture were ever to get into the wall cavity via condensation or otherwise. At the same time, the membrane does not let moisture into the wall cavity from the interior (showers, cooking, breathing, etc.), meaning the permeability is directional.

[@josephlaforney6922]

The taping around outlets is a good idea until drywall guy uses the rotozip.

[@MasonDixonAcres]

More about that in part 2 😉

[@CMCraftsman]

The tape is so good, the rotozip doesn’t even harm it.

[@court2379]

Foam the window, then pull the shims out and foam the holes.

[@MasonDixonAcres]

These are heavy tilt turn windows, gotta be supported solidly on all sides. For stock vinyl doublehungs that would probably work

[@court2379]

@MasonDixonAcres That doesn't matter in nearly every case. The foam has a strength of at least 1.5psi. For a 36in window and a jamb at least 5in deep, that is 270lbs of load the foam can hold. And that is just the bottom. Now add similar amounts for each side. No residential window this size weighs anywhere near that (maybe bullet proof glass would come close). And the load carrying capacity scales with the size, so it is unlikely to ever be an issue. Further if it is a new install, you usually have the nail flange and sealant under it, that holds the load to the framing. The shims are just to get it in the right place. Then on top of that you typically put moldings around the inside that are caulked and painted to it, and sometimes nailed too. The mouldings then nailed and caulked to the wall. You could leave the cavity around it without shims or foam and it would still be secure in nearly every case. Maybe a huge casement window could be an issue as it concentrates the force at the hinge, but it would be an exception.

[@MasonDixonAcres]

You are welcome to go against the manufacturers instructions/warranty and install very expensive, heavy, tilt-turn windows on only low density foam with no shims and report back how well they open in a few years 😆 Our dormer windows are over 300 lbs, and then you have to consider the forces of all 3 windows (heavy triple panes) swinging inwards like a door at the same time. Low density foam is not what you want. Like I said, for box store grade vinyl double hungs, you might be able to get away with that. But it's a silly corner to cut

[@court2379]

@@MasonDixonAcres Fair enough, you would not want to void the warranty on an expensive door/window and I would follow what they say as well for that reason. Though maybe cut the shims short so I can seal at least the outside completely. It's still probably strong enough, but getting each installer to do it consistently would be hard and lead to warranty issues. So I can see a manufacturer avoiding the whole issue. Just like they say to only use the low expansion foam when the other works fine with a little care and is better insulation. After setting the frame in foam. Pulling the shims, foaming the hole and putting it back in may not be a bad way to go. Plastic shims would be good too, as there is no rot potential or moisture wicking. I don't use the low expansion stuff so it is firmer and probably changes my perspective a bit too. If you use the regular denser foam you cannot just shoot it all in at once though or it will crush the frame. Run an inch diameter/width (expanded size) bead. Foam the corners first which are strong and a few dots along the length of the sides and let it set, then a bead all the way around, then repeat until the gap is filled. A bit tedious for one window, but when doing many, the first one is set by time you foam the last, so you just go in a loop a few times. I pull the shims out on the second layer.

[@perseoeridano4182]

👏🏻👏🏻👏🏻

[@richdobbs6595]

I'm going with Joe. No, it isn't worth it. At the cost of the material, if you had to pay for it, you would be better off applying more exterior insulation, to do a good enough approach (which you already have) with respect to your air barrier, and just go with no vapor barrier. No doubt that your approach is technically superior. But it is expensive and the gains are fragile.

[@richdobbs6595]

Joe Lstiburek, Ph.D., P.Eng - Moisture Control for Residential Buildings

[@richardshultz6834]

So you put tyvec on the inside?

[@MasonDixonAcres]

Not quite

[@kmosier22]

What???? Imperial is Superior! lol