Going 2x4

[Maineshop]

Today I decided to go with 2x4 walls with the Zip wall insulated sheathing. I can get the sheets locally at 1-1/2" for R6.6. That's a pretty crazy total thermal barrier when taped on the outside. There will be no wood transfer of cold indoors. The panels are a little more than going with regular Zip and urethane sheets, but a lot less work to install. They look like a very thin structural insulated panel (SIP). With those panels I see no need for 2x6 with 8' walls. I know 2x6 are generally straighter/better, but I'll buy a bunch and cherry-pick the lot and return the junk.

Window and doors will be earlier to install and finish. 2x4s are nearly 1/2 the price as 2x6, and the walls will be lighter to lift up.

I purchased scissor trusses today so with 8' walls and 1' of concrete, I'll be nearly 12' at the center of the garage.

I can't imagine what I'm missing, but open to suggestions.

 

[Steevo]

So, with R19 insulation in the 2x4 walls, plus the R6.6 from the Zip sheathing, you can have R25.6 walls, which is better than the R21 in my 2x6 walls.

Nice!

 

[Maineshop]

Yeah... The sheets are not cheap, but the labor saved (personal sweat) will be worth it. With taped seams, I'm sure I could just use the pink junk in the walls, but won't. I'll go with rock wool, possibly dense pack.

Feels a little strange going with 2x4 walls, but it makes sense. I'll go with California corners and advanced framing rules. Should see a significant reduction in labor and materials.

 

[mtwaterguy]

So, with R19 insulation in the 2x4 walls, plus the R6.6 from the Zip sheathing, you can have R25.6 walls, which is better than the R21 in my 2x6 walls.

Nice!

Looks like he's talking instead of, not in addition to the R19.

 

[readhead]

You are not putting R-19 in a 2x4 wall. You will end up with a R-19.6 for a whole lot more money and effort.

What is the structure? shed, garage, room addition?

 

[Maineshop]

Looks like he's talking instead of, not in addition to the R19.

mt... These panels prevent you from having to wrap the building after it's sheathed. Gets pretty cold in Maine. I'll definitely fill the cavities as well. This thermal break prevents intrusion through the stud walls. It's just an another layer of protection.

 

[Maineshop]

You are not putting R-19 in a 2x4 wall. You will end up with a R-19.6 for a whole lot more money and effort.

What is the structure? shed, garage, room addition?

Not sure what you saying readhead, but Roxul is ~R15 (2x4), plus the R6.6 sheathing is ~R22. And I get no thermal bridging. I'm happy with that combo.

This is for a garage. Is that what everybody's here for?

 

[walrus]

www.Buildingscience.com claims you need R10 on outside wall to keep condensation from happening in our zone. Something to think about

 

[readhead]

You left out that it was Roxul. How are you heating the building?

 

[theoldwizard1]

So, with R19 insulation in the 2x4 walls, plus the R6.6 from the Zip sheathing, you can have R25.6 walls, which is better than the R21 in my 2x6 walls.

Nice!

My daughter's father-in-law is a certified energy specialist, retired. He was a very strong proponent of SIP construction, but could not find a builder that would use it without charging a HUGE premium ! (Must be the cost of the crane.)

He doing a stick built frame using double 2x4 and standard ZIP sheating. The bottom plate is a 2x8 and the 2x4 studs are 24" O.C. but offset by 12". Sounds crazy, but he said the additional cost was really not that much.

His goal is to, "heat the house with a candle" !

 

[walrus]

My daughter's father-in-law is a certified energy specialist, retired. He was a very strong proponent of SIP construction, but could not find a builder that would use it without charging a HUGE premium ! (Must be the cost of the crane.)

He doing a stick built frame using double 2x4 and standard ZIP sheating. The bottom plate is a 2x8 and the 2x4 studs are 24" O.C. but offset by 12". Sounds crazy, but he said the additional cost was really not that much.

His goal is to, "heat the house with a candle" !

Thats not crazy, been done for years. No penetrations in outside wall (except windows, doors), all piping, electrical in inside wall. Should make for a nice tight building.

 

[Kaizen]

Maine where are you ? Can you quote the price and place you are getting them? Do they have them for the roof as well? I haven't seen anything but normal zip panels around here


Sent from my iPhone using Tapatalk

 

[Maineshop]

Kaizen... You can get them from a lot of places these days. If you go to Huber's website (below) you will find dealers on one of the links. I asked my lumberyard and they said "no", then I asked "are you sure", then they said "oh, I guess we do". You can get them in 1" R3.3, or 1 1/2" R6.6. They are nice panels from what I can see. You can custom order them in 10' units, but $$. $48.00 each is what I remember. So you sheath, insulate, and no need to mess with a vapor barrier. It's a no-brainer for DIY. The material cost was maybe $2 more pre 32sqf, but big time savings. I got mine from Hammond Lumber. I'm just north of the fine city of Portland, ME.

http://www.huberwood.com/zipsystem/products/zip-system-rsheathing

 

[Maineshop]

Wiz, We built our last house out of SIPs about 9 years ago. It was not easy. Everything was more money, including the crane that drove up to VT from MA... Uhhhh. It was an awesome house though. Three floors of radiant. Very comfortable. I'd do it again now that I struggled through the first go around.

The building actually caught on fire and I was able to put it out. Crazy fumes from the foam cutting. I stopped to talk to somebody who asked me a question while I was cutting the foam with a hot knife. Within seconds it burst into flames and ignited the fumes and burned up the center of the roof all the way to the ridge. Imagine a giant 4'x16' styrofoam cup on fire! By the time I got it out, I lost 2 full panels and almost lost the entire house. Was an expensive mistake. It took me a second to realize what was going on because I couldn't see the flames. It smelled bad and there was a giant sucking sound. The fire extinguisher was sort of close by. A guy I was working with had to run and find find it, then threw it up to me on staging. I caught it and was able to blast it up between the roof panels.Panels were like 10" thick. Can't believe it put it out. Scary...

 

[Maineshop]

Read, Radiant slab...

 

[NUTTSGT]

Sounds like you have it figured out. I was going to question the 8' walls but you seem to have that covered as well.

 

[Maineshop]

Nut, I was going to do 10s, but with the scissor trusses and 1' of concrete wall height, I think it will be enough. The Trusses are 7:12 outside slope, with an inside slope of 4:12. I'd like to keep the overall enormity of the building down.

 

[NUTTSGT]

Nut, I was going to do 10s, but with the scissor trusses and 1' of concrete wall height, I think it will be enough. The Trusses are 7:12 outside slope, with an inside slope of 4:12. I'd like to keep the overall enormity of the building down.

Like I said , I think you have it covered. The only place I might see you having an issue is if you build stuff and utilize 4x8 sheet goods. ...just watch your lights.

 

[JohnK007]

This sounds interesting. How about starting a build thread when you're ready to get going? I wanna see.

 

[Maineshop]

This sounds interesting. How about starting a build thread when you're ready to get going? I wanna see.

I definitely will start a build thread. I'm right at that point where it makes sense to begin.

My foundation is a frost protected shallow type, which some will find interesting, and some will think I'm nuts

Off to Cape Cod for the weekend. Get something going next week.

 

[Maineshop]

. ...just watch your lights.

I plan to go LED inset cans for that very reason. Nothing hanging down

Maybe I should go 10' with blocking. Hmmm. Indecision kills my productivity. Something to decide about over the weekend.

 

[MagKarl]

How are these panels constructed? Is it foam attached to outside of OSB?

Another thing to consider is 2x6 walls give you a lot more stud meat when it comes to wiring/plumbing, etc.

 

[theoldwizard1]

...So you sheath, TAPE, insulate, and no need to mess with a vapor barrier.

I added the key step you forgot !

 

[theoldwizard1]

Wiz, We built our last house out of SIPs about 9 years ago. It was not easy. Everything was more money, including the crane that drove up to VT from MA... Uhhhh. It was an awesome house though. Three floors of radiant. Very comfortable. I'd do it again now that I struggled through the first go around.

So what would you do different to hopefully contain the costs and minimize headaches ?


If win the lottery, I'll build a house on a lake and would do it with SIP. 1-1/2 stories, cape cod. The roof (12:12) would require some really LONG panels and with wood I-beams for side supports.

 

[theoldwizard1]

How are these panels constructed? Is it foam attached to outside of OSB?