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Community and Q&A

No one wants to do Advanced Framing!

Irwin Karwick | Posted in Green Building Techniques on

I have been reading many of your articles on advanced framing… 2×6 walls 24″oc. As I was planning the construction of our new cottage, I consulted with many subcontractors on advanced framing. Without exception, each one (insulation, framing crew, siding, trim) all advised me against going that route. They discussed issues like difficulty hanging cabinets on a wall 24″oc, wavey siding, the need to go to 5/8″ drywall to avoid wavey interior looking walls, the lack of studs for wide window & door trim and even…. “the house will be too tight” ! How would respond to that ? I was surprised and disappointed…. I think I am going to go with 2×4 walls, 16″oc w/1″ rigid foam sheathing.

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Replies

  1. User avatar GBA Editor
    Martin Holladay | | #1

    Irwin,
    There are two issues here:

    1. Some of these builders -- for example, the one who told you "the house will be too tight!" -- are simply ignorant. That's frustrating, but fairly common. Don't give up -- keep searching for a progressive builder. You might ask your local lumberyard to suggest the names of builders who specialize in energy-efficient construction.

    2. Some of the builders have a point. Remember, 24-inch-on-center framing is not a cure-all. It's just one method. And since it doesn't really address thermal bridging -- it just reduces it a little -- it may make sense to listen to builders who prefer 16-inch-on-center framing, and simply add more rigid foam on the exterior of your walls.

    All of these decisions involve trade-offs. While it's true that you can use Advanced Framing to get a great house, you will also give up some flexibility when it comes to installing trim and hanging cabinets. And yes -- your siding and drywall will not be supported in the same way.

  2. Christopher Vlcek, Littlewolf Architecture | | #2

    Eliminating thermal bridging due to framing is a huge part of creating an efficient envelope. Exterior foam sheets or double stud walls are the best way to do that. Depending on your climate, 1" might be sufficient to eliminate condensation within the stud cavity - but 2" would be better. Many advocate R40 for walls, R60 for roofs, R20 for basements, again depending on climate. Poly-iso foam board has much less of a global-warming footprint than does XPS aka 'blueboard'.

    Advanced framing would be the next step after a double-stud wall or exterior foam. It doesn't eliminate thermal bridging, but reduces it by about 15-20%. Carpenters need to plan out the floor, wall, and roof framing more carefully - wall studs need to align with floor joists, and rafters or trusses do as well. Metal straps are used to tie the wall corners together instead of double top plates. Yes, 5/8" drywall is required for the exterior walls framed at 24" OC - a small upgrade. Cabinets can certainly be hung, and you can 'let-in' 3/4" blocking if required - prior to drywall. Trim can be pocket-screwed or biscuit joined at the corners to increase strength, or again, let-in 3/4" blocking if necessary. So there are a few added costs - but largely offset by the reduced lumber. But the real payback starts once you start paying for heating. A well- or super-insulated house is an investment in the future.

    Also, tight houses are not the enemy at all, in fact that's what we're striving for in energy efficient building. Fresh air is best brought in by an HRV or ERV, although running an efficient bathroom fan can also be used for that. The blower door test gives a value for tightness, and code requirements and performance standards are stressing the importance of tight building.

    Best to find a GC who is familar with green building in general. And someone who can plan out the details prior to construction. There is a lot of info on this website and others regarding all of these points.

  3. User avatar
    Michael Chandler | | #3

    I had difficulty with my framing company, who's owner was a close family friend and a person I enjoyed working with, but who's crews continually back-slid on compliance with my framing details and hurricane influenced nailing schedules. So I've gone to working with a panelizing company where the smart folks programming the wall designs into the computers that optimize the material usage and mark the plates for the assembly team are much more receptive to systems that use less lumber and produce a better product.

    It costs about the same but the house goes from foundation to dry-in in less than three weeks, every wall panel is drawn and presented for approval before fabrication, and there is no issue with getting the sheathing fastened 3" O.C or holding the sheathing up a foot off the bottom plate to allow site applied strips to bridge from the studs, past the band to the mudsill for hurricane resistance. And 100% of the wood scrap is sorted and recycled at the plant so there is much less waste to deal with at the job site.

    It's a little awkward running into my framer at my kids school events but he dealt that hand to himself.

    (I'm a bit rigid sometimes though, I fired my own daughter when she paid the company bills on the eleventh and missed the pay-by-tenth discount because of a big party.)

  4. Riversong | | #4

    I can sympathize with contractors who are skeptical of "advanced framing", because of the many liabilities outlined here by others. But I have to shrug my shoulders at the term "advanced" applied to this rather mediocre approach.

    It was developed by HUD in the 1980s as "Optimum Value Engineering" as a way to reduce the use of wood products in new construction and then morphed into "Advanced Framing" as a way to reduce thermal bridging and increase energy efficiency.

    However, for all the liabilities of the system, the benefits are minimal. A typical new house has about 25% of its wall area in solid wood, while the same house framed on 24" centers might have 22%, and a house framed with the Full Monty OVE/AF approach might have as little as 16% thermal bridging. That's still an enormous portion of the exterior walls.

    As mentioned, exterior foam has become the quick-and-easy method of reducing thermal bridging, but I have long contended that it introduces another set of unintended consequences in terms of moisture management and durability.

    The only truly advanced framing techniques are the several variations of double-wall framing and my modified Larsen Truss framing system which uses less wood than a conventional frame while almost eliminating thermal bridging and allowing almost unlimited R-value (my walls are R-45).

    And double-walls or Larsen Trusses allow all the interior and exterior nailing necessary for any trim details without increasing thermal losses. As to the insistence on using 5/8" drywall - I've never used anything but 1/2" on 24" centers and have never had either interior or exterior problems with planarity (waviness), even with dense-pack cellulose pumped in behind it or 20" of loose-fill on the ceiling.

  5. Chris Harris | | #5

    We recently designed a house with stud walls at 24" o.c. But because we were maxing out the spans for the floor joists, they had to remain at 16" o.c.

    Because of the shear requirements we end up with a ton of 2x6posts in the walls and corners, so there really is nothing advanced about this particular project other than we saved a little material and were able to get a little more insulation in the walls.

    Building Science claims to have little to no issues w/ staying with 1/2" blueboard or sheetrock on 24" o.c. walls.

    You pick your battles. I love the ideas presented by advanced framing, but how often are we designing houses where all of the openings align in elevation. We'll continue to apply as much of it as possible (2 stud corners, ladder framing at wall intersections, aligned 24" spacing, etc.), but know that sometimes it just doesn't work.

  6. User avatar
    Danny Kelly | | #6

    Irwin.
    Advanced framing, like green building has several different levels (or shades of green I like to say) of complexity. How far you go depends on your climate and your comfort level. I went to school for structural engineering so for years I took pride in how overengineered my homes were and was very reluctant to accept any advanced framing techniques. Over the years, as I have learned the benefits, I have begun to implement them more and more. Some of your decisions will also dependon the complexity of your house (this is why green building should really begin at the design stage). Start with the no brainers - 24" OC will allow you to upgrade to a 2x6 wall, ladder "t-wall" intersections, two stud corners, insulated headers, etc. The next step is the single top plates, eliminating jack studs, etc. You only have to do what you feel comfortable with and every step you take is a step in the right direction.

    According to the Sheetrock manufacturers - 1/2" is fine in a vertical plane. We use finger jointed studs when we do this - they are much straighter than typical studs so did not have the waviness issue (this also got us some points on our LEED-H certification). You do have to add some blocking for trim and cabinets but not a big deal - can use scrap or rip down 2x4s for nailers - this is better than using a full depth stud just as a nailer as done in typical construction.

    Anyone still using the "house will be too tight" excuse just doesn't get it and probably never will. There are plenty of people out there that understand tight construction - you just need to find them.

  7. Riversong | | #7

    Anyone still using the "house will be too tight" excuse just doesn't get it...

    The way it's typically used, that may be true. But there's another meaning of that statement most "green" designers and builders don't get.

    A house is our third skin - after our biological skin and our clothing. Ideally, all of our skins can "breathe"; that is, are permeable to moisture exchange. Nothing living has an impermeable membrane isolating it from its environment. Life, in fact, requires semi-permeable membranes for mass and energy exchange with the environment.

    The "tight house" movement has gone from the sublime to the ridiculous, celebrating the most hermetically-sealed boxes as the pinnacle of building technology. We build oversized picnic coolers and then install mechanical life-support systems because we've encased an interior environment that is inhospitable to life.

    Using biological principles, a shelter would ideally be composed of natural, hygroscopic and vapor open materials and membranes. This not only allows vapor flow, storage, and release (buffering indoor relative humidity the way thermal mass buffers indoor temperature), but also allows the building envelope to dry out (and in) when (not if) it gets wet, typically from external environmental bulk moisture. Using such materials also naturally enhances the negative ion count in the interior environment, which are essential to physiological and emotional health (all plastics remove negative ions from the air).

    So, yes, a house can be - and, in the case of most "green" homes, is - far too tight.

  8. Hunter Dendy | | #8

    Robert, so then do you think that air-flow tight is the goal, but not necessarily vapor tight?
    I've just been reading this site (daily) for about a month now and have been intrigued with your posts. As a designer trying to do the right thing, it's too easy to keep hearing 'tight tight tight' and think it's the only way to go and not reflect on what really makes sense. This makes perfect sense. Still trying to wrap my head around all the details though.

  9. Riversong | | #9

    Hunter,

    Here is the dilemma: we Norté Americans believe it's our unalienable right to build or own castles to our egos, limited only by our ability to secure debt financing and what a banker will be willing to lend us (and we've seen the consequences of that). Not only do our castles require huge amounts of physical resources to create, furnish and maintain but also exorbitant non-renewable resources to heat and cool and provide unlimited hot water - all of which then requires an aggressive foreign and military policy which triggers blowback ("Why to they want to kill us?").

    That is the unquestioned premise from which all these technical discussions flow, which makes the answers, invariably, inadequate and misguided.

    But, given that, we must find ways to satisfy our endless wants without consuming so much fuel. That's required ever-better insulated homes. But insulation, of course, is only part of the equation. We must also limit air exchange because that not only becomes the largest source of heat loss but may also cause accelerated disintegration of the structure and possible health problems. It can cause accelerated disintegration of the structure and possible health problems because our excessively insulated homes no longer breathe water vapor or allow sufficient convection to dry out the structures. Our response to that is, of course, to make the assemblies even more impermeable and eliminate most structural venting (crawl spaces and roofs).

    So, it seems that there's no choice but to install increasingly sophisticated mechanical life support systems, which are called HRVs and ERVs in order to exchange air and water vapor without undue loss or increase of purchased energy. Taking this trend to its logical conclusion gives us PassivHaus and Remote/Persist and Zero-Energy Homes (which use additional high technology to compensate for our wastefulness).

    What no one wants to acknowledge or discuss is that, if we were to build and buy and live in simple, basic shelter, then we could achieve very low levels of both resource and energy consumption without going to extremes.

    So, given that we have put ourselves between a rock and a hard place, what is the optimum point of balance? That's what I've tried to aim toward in my 30 years of designing and building passive solar, super-insulated homes: high levels of insulation using local renewable or recycled, natural, non-toxic materials; very good but not extreme air tightness; the simplest possible mechanical ventilation system that can also function to some degree when the grid is down; and heat from the sun and locally-produced firewood whenever possible (at least here in the rural northeast).

    I think I've come close to that goal, though I now believe that more local, natural materials (such as straw bales and clay plasters) would improve the model.

  10. smalld | | #10

    Robert
    As a builder/designer, project supervisor and former Building Technologies Instructor with some 40+years of experience, I can only say; a big 'thanx' that you are out there. That you continuously trying to remind the various design and building 'communities' about the reality of construction. I too, am often astounded by the proposals espoused by so many 'experts' that the ideal home/structure is similar to a dry cleaning bag, efficiently sealed, and provided with one hole to discharge stale air, another to introduce fresh air, provisions of course being made that the opening(s) be sized correctly to provide for the number of inhabitants, the activities undertaken by the occupants and controlled by high tech systems, which demand ridiculously high energy for manufacturing, and a constant energy demand.
    And this seems reasonable to most super tight structure advocates.
    As you say, we do transpire and we do breath, everything on this planet breathes and/or transpires, but according to them a building must not - except by the aforementioned unreliable, costly and short life term technology guiding it. Kind of like a pacemaker (well- they are amazing), but ignoring the initial creation of a healthy heart. As well they tend to ignore that we, that is all lifeforms, utilize the energy of the sun, and all its various atmospheric influences, [even those life forms deep within the ocean,(although some may not comprehend the 'link' with them)].
    I constantly amazed and confused as to why - the green/energy efficient experts do not/will not recognize that in order for our buildings to be efficient we can and must quite simply emulate the systems of our environment/ecology. Natural systems that have been so efficient for millennium. Yet they insist on advocating designs that ensure we isolate ourselves or our buildings from the environment, and conflict with the ecosystems around us.
    Breathing, transpiration, reflection/retention/transformation/utilization of solar energy in its myriad forms, these are only a few of the many freely available insights/lessons our planet and its ecology offers us, there is so much more that we have only just begun to realize. Unfortunately, so many still believe and insist that is only by disconnecting and isolating buildings can we be green or energy efficient. Mmmm, I wonder?
    Keep up the challenges, I for one continue to do so in all my design, consulting and building projects, and continue to look forward to your insights, wisdom, and critiques.
    Thanx!!!!!

  11. cgranda | | #11

    In 2005 my wife and I realized a dream of ours and built a house in rural Vermont. I've been in the residential energy efficiency industry for 25 years and was determined to practice what I had been preaching, including advanced framing. It was tough to get the crew on board and I didn't go as far with it as some advocate. I have a three story house where the second and third floors are all 2X6 24" on center, and the corners are mostly two stud. The builder wouldn't budge on double top plates. We used regular .5" sheetrock. The windows (Marvin Integrity) and doors were all stock.
    I'm happy to report that so far we've had no problems with wavy walls or other dire consequences that were predicted. We went through the Efficiency Vermont ENERGY STAR homes program and the house has proven to be more efficient for space heating energy than predicted when construction was completed.

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