Opinions on Klingenberg Wall vs Other Common Assemblies
arnoldk
| Posted in General Questions on
Hi,
I am in the final design stage and getting ready to select a wall assembly for the builder who will be doing the weathertight assembly (framing, sheathing and windows/doors). Living in Ottawa, Canada, we are aiming for a wall R-Value of between R-50 and R-60, depending on the energy model.
This builder specialises in Passive House and primarily uses the Klingenberg wall (see attachment) but is open to other wall assembly.
Are there any draw back from going with the Klingenberg versus a double wall or 2×6″ with exterior insulation?
Thank you,
Arnold
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You can enter "Klingenberg" in the upper right search option.
I already did that years ago.
That's more of a Larson truss wall. On the Klingerberg wall, the sheathing would be on the inside not in the middle.
Personnally, I'm a big fan of these walls if you are aiming for a R value above 40. Otherwise, it's cheaper to just add exterior ridgid insulation on your wall.
I agree with Alex, for super high-R walls, this approach seems to be settling out as the most popular. For slightly better than code-minimum, exterior insulation is usually the most cost effective. In between, around R-30 to R-40, double stud walls, in my experience, usually make the most sense, though some builders prefer exterior insulation for those walls as well.
I disagree with Alex about the sheathing. I believe locating it on the exterior of the structural layer is Klingenberg's approach.
Hi Michael,
The builder does a wood fiber sheathing (Agepan) in the exterior of the I-Joist which they use as their air barrier while the sheathing on the 2x6 framing (Zip Sheathing I believe) is the vapour barrier.
This is one area of their wall assembly I will discuss with them to see if we can't incorporate both the air and vapour at the Zip sheathing.
Thank you,
Arnold
Arnold, the builders I know who have tried Agepan or other wood fiber panels on the exterior have switched to waterproof membranes such as Pro Clima Solitex Mento. The wood fiber tends to bow out when the cellulose is installed at proper density.
A 16" TJI will get you to an R-56 assembly without any batts on the interior. You can then reduce the 2x6 interior to 2x4 and leave it as an empty service channel.
The Passive House I viewed under construction in 2007 had fiberboard exterior sheathing and housewrap as I recall. The wall sections were made off site and used blown fiberglass for the insulation. The interior of the TJI wall was sheathed with OSB to which a 2" x 3" uninsulated service cavity was attached. The service cavity walls actually supported the upper floor system so the OSB interior sheathing could run continuously from floor (slab) to ceiling.
Thank you for all the feedback. For the last few years I had thought about doing an R-40 wall assembly and was leaning towards 2x6 with exterior insulation which is where most of my reading had gone.
I just want to make sure Larson / Klingerberg wall assembly has been well received and tested since I don't have to financial means to try new construction method.
Thank you,
Arnold
Another version of what you're trying to do can be seen in this episode of BS + Beer at around the 45 minute mark:
https://youtu.be/cXDaGG-v_60
Or you can google "site built larsen trusses" under images to see a variety of different strategies.
You or your builder might see something worth trying, even if it's just initially a mock wall assembly to explore options.
Thanks for the link Eric. I'll check it out.
That's a good example, Eric. I like how simple and affordable it is.
More similar to the Klingenberg wall is the Ecocor Passive Wall, which I talk about around 55 minutes in here: https://www.youtube.com/watch?v=QLab3gRnvF8. Christine's introduction is worth watching as well. And the other wall assemblies shown are also very good. Just watch the whole thing ;-)
As others have said, this is a fine option. In choosing between different options, a key consideration is that the cost and quality usually come out best if your builder is already familiar with the particular design to be used. If you've got a builder lined up who has done this and likes it, that easily tips the balance to this approach over other options.
And even without that consideration, it's a good approach.
The next question might be the detailing of the windows. With a super-high performance wall like that, and high performance windows, the way the windows are installed--the location of them and the details of the materials used around them--can be a significant factor in how close you get to the ideal potential of the two based on their individual U-factors.
Hi Charlie,
This builder promotes Passives House and has almost 12 dozen house plans which all use this type of wall assembly and guaranties PassiveHouse certification if followed to a tee. In our case we are not interested in going that far and will be install a bit less insulation than what would be required.
Thank you,
Arnold
The wall as shown is pretty expensive to build. Looks fancy, but not very good value in terms of $/R.
If you get a good structural engineer, you can go with I-joists alone as structural wall and save a lot of complexity. Even if you go with thicker I-joists for more R value, it would be significantly less materials and labour than the wall sketched.
Not 100% thermally broken but close enough (ie 14" I-joist with dense packed is around an R45 wall, vs R54 with no thermal bridging). You can get almost all of that R value back with fiberboard sheathing and an 1" of polyiso on the interior. Still way less work than what is proposed.
If you must have the R50-60 wall, I can't see why you would go for anything other than a simple double stud wall.
P.S. I'm not sure where you'll find a roofer to walk on a fiberboard roof especially with 24 OC trusses. I wouldn't.
The best wall is the one your builder has built cost effectively and will warranty. You say your builder is experienced with Passive House and the wall assembly they use is used by many other passive house builders. I don't see what your concern is. As long as you also did the passive house energy model then you will get predictable low energy usage and a comfortable home with excellent indoor air quality. Making your builder build a one off wall assembly most likely will cost more then the one they are familiar with.
Hi Arnold:
Apologies for hijacking the thread but I noticed you mentioned you are building in Ottawa. We are researching a new build in the Ottawa area and would be grateful to hear about your experience with any high performance builder in the area. If possible can you provide the name of the contractor who primarily uses the Klingenberg wall assembly, and if you are comfortable how your experience has been with them.
Cheers,
Sean