Friday, June 08, 2012

Learning from Swedish Home Building - Part 2

Time to look at Part 2 of our video series on building Nordic style walls in the US. Today we look at the USA New Wall, and its Good, Better, Best versions which make it easier for American builders to step into high performance building.

In the first video, you may recall, we briefly reviewed why we would look to Sweden to inspire the way we build houses in the US. This next video shows how we can apply the lessons from their wall construction to building here in the US. We offer these improvements in easy to achieve steps. First get familiar with better insulation, then introduce a wiring space to your walls to make it easier to keep the house air tight, then complete the picture with an exterior insulation layer that makes a good thermal break for the wall framing. Here is Part 2:


This video piece shows how to go about building Nordic Style walls for residential construction, like the walls used in Sweden. We call these American versions of Nordic walls the USA New Wall.

The wall systems have been broken down into Good/Better/Best subsets in order to offer builders a gradual path to increasing the performance of the walls they build. The video starts off with a detailed look at a typical Swedish wall, and then walks you through the Good, Better, and Best versions of the USA New Wall.

The USA New Wall is explained in much more detail on our web site, and you can read that on this page:

http://blog.lamidesign.com/p/usa-new-wall-info.html

You will note that all of the wall variations feature Stone Wool insulation rather than fiberglass. We mention in the video that this is because Stone Wool offers higher insulation values - R23 for 2x6 stud spaces, and R30 for 2x8 stud spaces. We also mention that it allows for better installations. You can read a detailed article about why this is so on our blog:

http://blog.lamidesign.com/2012/01/what-you-don-know-about-mineral-wool.html

Also mentioned in the video is the Variable Permeability Vapor Retarder membrane. There are several sources for this unique vapor retarder, notably Certainteed's Membrane:

http://www.certainteed.com/products/insulation/mold-prevention/317391

And Intello Plus, and DB+ by ProClima:

http://foursevenfive.com/product-category/air-sealing-system/interior-membranes-air-vapor-control/

You can read the entire Letters from Sweden series on the blog.

The USA New Wall, and Swedish Platform Framing are an outgrowth of our research into Swedish building practices. Again, you can find details of the USA New Wall here:

http://blog.lamidesign.com/p/usa-new-wall-info.html

And Swedish Platform Framing here:

http://blog.lamidesign.com/p/swedish-platform-framing-info.html

If you need assistance implementing the USA New Wall or Swedish Platform Framing in your projects, we are here to help. Please contact us.

11 comments:

  1. Greg,

    Thank you for putting this together in a video format and explicating the process. I think it helps expand upon the understanding of some of the esoterica that we, as architects, talk about in our own, almost innate, language, that may be lost on others who are unfamiliar with these techniques.

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  2. Thanks for that feedback. Architects are not the target audience, so I'm trying my best to make this accessible.

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  3. Great work putting all of this together! Not sure if this is the place to put these comments but couldn't go to the link
    http://blog.lamidesign.com/p/usa-new-wall.html

    Currently in the planning stages of renovating a home on Marthas Vineyard about 1200sq ft one story.

    Love the best wall construction, but the budget is tight. I am thinking of modifying it a bit (with my limited knowledge set).

    First I am stuck with 2x4 walls, no changing that.
    Definitely using Roxul.
    Second going to start by ignoring the exterior for now as it is sided currently and probably has another 5 years of life. When I do re-side I will add Roxul on the outside ( maybe like the Rockford design). When I do paper, housewrap, or zip? Also backvent or not with cedar shingles?
    On the interior wire chase how do you feel about using 1.5" strips of foam combined with 1/2" strips of plywood for the furring strips? To completely eliminate thermal bridging. Also what is the standard spacing for these strips.
    For the vapor barrier I was thinking of continuing it into the basement below by cutting back the floor maybe 4" or so from the wall placing it on top of the joists and then replacing the floor. In the basement around the rim joist and between the rafters I would spray foam making sure to include the vapor barrier from above in the application. Then using rigid foam insulation on the foundation walls and floors to continue the vapor barrier.

    Ceilings?
    Assuming what is good for the walls works for the ceiling too? Only problem is recessed lights I was thinking of false ceiling instead below the best wall/ceiling construction?

    The siding is cedar shakes. The ceilings are a mix between vaults and flat. There is a full basement with a small crawl space as well.

    One challenge I have is the windows are going to be replaced, but need to be ready for the application of the roxul on the outside down the road. Maybe pad out now for the additional wall thickness later. (prefer outside mount to recessed pockets).

    I am not a builder, but have been in the trades for 17 years. Mostly working on enormous high-end homes (not McMansions but the real McCoy). Its funny only a few of them employ any techniques even close to what you bring to light despite cost not being an issue. Sure they use the best boilers, spray foams, and windows, but thermal bridging is rarely thought about. Continue the great work!

    Thanks
    Brian

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  4. I fixed that link - thanks for the heads up.

    Listen, you have the right idea, but you've hit on too many questions for me to respond to here, and frankly too much for me to respond to for free..!

    Hit me up for a couple of hours of consult if you want to discuss these questions in detail.

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  5. I'm a few months behind the post here, sorry. I'm curious how these internal vapor barriers avoid being punctured by homeowners hanging pictures or doing homeowner type things? It seems that a few careless nails ruin the whole setup. Am I missing something? Also curious how the wiring chase prevents punctures if the standard switch or socket box is something akin to 3-4 inches deep and the chase is only 1.5-2 inches. Doesn't the box puncture the membrane?

    Love the effort you put into the site! Thanks

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    1. No problem Lael, these are common questions, and I really ought to create an "answers to common questions...".

      Will the air tight vapor control layer get punctured if the homeowner hangs a picture? Not generally. The picture would have to be hung with a big nail to extend the 2" to the membrane, longer if put in at an angle. That said the homeowner does have to be aware of what they are doing when hanging a shelf or something.

      Electrical boxes are readily available in 1.5" depth. For an outlet or light switch you would use a 1.5x4x4 box, with a switchplate reducer cover. That is a 4x4 cover that has a rectangular opening that matches the size of switch and outlet devices, and extends the 1/2" through the wall board. Its a little different than the norm, but nothing strange and keeps everything inside vapor control layer.

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  6. Brilliant in the simplicity; forget the half-moronic Advanced Framing method which, initially, was created to save on framing material--it always felt chintzy anyway. Here is a building system that is so builder-friendly; so easy to comprehend and is usable for any style home----whether offsite/modular construction, or site built or roughed-in a barn with basic carpentry tools. It's all about a very sytematic ,clear cut, easy to comprehend, easy to build with readily available materials and with basic knowledge in most builders' current toolbox.........let'sget going and do this builders of America, of Canada. I'm sure the early stick/balloon frame builders were looked upon with disbelief and derision by the then timber framing community and with thoughts that 'them little sticks won't never hold up!' Here we are decades alter and we're still flopping around with this method, that method...oh-oh, let's try this method............HEY! The Swedes hae proven for nearly forty years that this works!!

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  7. Curious about the vapor control layer. I'm in climate zone 5 - Northern Arizona. If we can separate air tight from vapor control, can the drywall painted with latex paint (perm rating of 1-2) suffice if gasketed and penetrations sealed? I know the homeowner will poke holes in it and I'm operating from your "good" wall design - so the independent vapor layer would be penetrated as well. I've read lots in the past and getting your take would be another dependable voice of consideration.

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    1. For the Good wall, sure, you could approach it with the latex paint vapor retarder. Aside from the shortcomings you point out the big compromise from not using the vapor sheet is the loss of the variable permeability function offered by the "smart" vapor control sheets. These allow the wall to be responsive during the cooling season when the vapor profile of the wall reverses, and also gives you a better chance of avoiding trouble if you have a leak elsewhere letting moisture into the wall. It just gives you better drying potential.

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  8. my 2x6 house has most of our walls up, we will be dried in in 6 more weeks. I have been stewing over foam vs rockwool. At this point I expect to use roxul. R23 exterior walls, r30 in 2x8 roof. Am in texas, tons of humidity (near Austin). very little if any heating done here. I am debating the smart vapor barrier sounds like a good idea, but in the past vapor barriers on interiors here cause mold. smart, sounds appealing. I am also curious how I add the external layer. normally it would be sheathing, then hardi plank.

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    1. You are in texas, so the vapor profile of your wall is reversed from the model walls I am describing here. If you want more advice, contact me direct, and hit the tip jar near the bottom of this page: http://blog.lamidesign.com/p/usa-new-wall-info.html

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