Hi, I was reading the interesting thread here, ICF vs stick-built for DIY, and learning a lot. In that thread, a poster discussed some advantages of stick built and said:
”…The lowest cost will probably be the stick framed wall - either double stud or stud with outsulation (foam outside the sheathing). The difficulty is usually in keeping the infiltration rate low, but that’s exactly where the DIY or conscientious builder can make a substantial difference in paying attention to details that will affect infiltration and therefore overall performance. Tight framing, caulking, taping the joints of ZIP sheathing and taping the seams of the outsulation can yield the results you need….”

This is very interesting to me because I will be building (hiring a framer) a stick built house (2x6 with outsulation) next year. Given this building technique, I wonder if anyone could comment on:

- What does “tight framing” mean? Does that refer to the tape and cualk effort or something in addition to that? 

- How would you go about evaluating potential framers to know they would be able to do the type of framing you want? This seems especially important when so many houses are built without specific care in this area – it just isn’t the norm, unfortunately.

- I’ve done some reading on optimized framing, or advance framing (not sure of the correct name right at this moment). I would be interested to hear others experiences or the opinion of professional builders how much this type of framing is actually used. In my area, it does not seem common at all.

Thanks!

I have had the same questions, and I would love to hear how people in the industry respond.

Green building is not common in my area either, which makes me hesitant to hire a builder.  I am capable of DIYing our next house, but I really don't have the time.  I'd prefer to hire a contractor, but I have concerns about finding one who will be able and willing to pay attention to the details. 

BabyBldr - like with most things, the devil is in the details!

You can build a very good, tight house with 2x6 framing and exterior foam sheathing - if you and your builder pay attention to how things are put together! Stick framed structures are economical and fast to build, but because they are made of so many parts, there is a greater potential for air infiltration.

Paying attention to how all the joints in the foam sheathing are taped, sealing all areas around the rim joists as well as all wall penetrations, and effectively air sealing leaks between the interior living space and the roof system are all critical to having a "tight" house. Most contractors are not too interested in all of these details unless you make sure they are. You have to specify exactly what you want and check to make sure things are done as specified. I would suggest you go through the framed building before wall insulation is installed and foam any openings you find (electrical and plumbing penetrations as well as any crack or crevice). Do this on interior walls, top and bottom plates too.

Using spray foam on the rim joist and in the attic over any interior walls or penetrations can greatly tighten up the house. A blower door test before attic insulation is installed can also help find air leaks.

Most houses are framed with 2x4s on 16" centers. If you want to use an advanced framing technique such as 2x6 on 24" centers, you need to specify what you want. I would also suggest using 5/8” drywall on the interior walls with 24” centers.

Paying attention to the details is how you build a “tight” framed home.

Besides sealing bottom plates to whatever they are resting on and wall splices and framing with the "big" picture in mind as far as having proper backers and appropriate blocking there isn't much a framer needs to do. It's after framing that we switch gears and tighten everything up including stud bays, redundant btm plate sealant, wall splices, top plate joints, multi ply trusses, beam pockets, ect.

I agree with greentree. Any capable framer will be able to frame your house to specifications. Framers also include sheathing and wrap, but probably not to the level of quality you want unless you stress requirements upfront and supervise and inspect the result. I think the biggest mistakes are made insulating the house. If you can find a contractor that knows how to insulate a house for low infiltration using a combination of techniques you will likely achieve your goals.

You will have some help in Pa. Starting this year, new construction must pass a blower door test as part of the energy code requirements. As an alternative, the builder can ask for a series of inspections of air sealing requirements similar to this Ga checklist: http://www.dca.ga.gov/development/constructioncodes/programs/documents/IECC.TF.Air-SealingKeyPoints.pdf
Use this list to monitor your framer's attention to detail. Ask to be present at the blower door test, and for time during the test to look for leaks and time after to correct them, even if the house passes. You might get some push back: "good enough the inspector..." but the fact is that caulk is cheap and fixing leaks is much tougher once the wall board and the siding go up. Your builder will be worrying about time and labor so tell him you will DIY additional sealing and do it quickly.
How much caulk? Depends. The last time I stick built, I had a major elevation facing north, a full-length porch roof that packed the wind against it, and zero wind breaks. I caulked everything on that wall that would hold a bead. Today, I would spec a thin coat of spray polyurethane to seal it. As a part of your hiring questions, ask builders to look at your design and your site and suggest additional sealing measures.

Knauf has an intersting water based product for air sealing, Eco Seal I think it's called. I haven't had a pail quoted to me yet though. Biggest benefit to me as a contractor would be its ability to seal double plates and beams/girders quickly and effectively. You need a bigger spray rig to use it so the DIY'er is a bit screwed in that regard.

As far as air sealing materials a 5 gallon pail of Eco Seal lays 2000 l.f.; a 20-24 oz can of gunned 1 part foam will lay nearly 2000 l.f. for $10 plus the gun and I'm willing to bet a 5 gallon pail of Knauf is a bit north of $10; a tube of Quad (or other quality polyurethane sealant) runs in the neighborhood of $4 each and covers roughly 35 l.f. or 2 standard stud bays. Clearly 1 part gunned foam is the fastest most cost effective way to seal bays, junctions, gaps and any other need at the thermal boundary inside the plane of wall covering. On the wall covering plane caulk or a product like eco seal or Owens Corning energy complete would be necessary.

Proof of the quality of OSI Quad sealant: I had used it to air seal some bays to use up some leftover tubes a few weeks ago. A window was placed into that area on a change order so we cut the sheathing the size of the window and when we pulled the sheathing off the stud that was to be removed and had been air sealed with Quad half the sheathing stayed on the stud due to the sealant bond. The guys had to beat the sheet off the stud. Very few readily availabe sealants/caulking will match that bond.

My framer/carpenter did not know what OVE or advanced framing techniques were and really did not give a hoot about energy efficiency, BUT whoever trained him taught him to use those techniques (california corners, bridging for partitions walls etc) for lumber saving reasons. So I guess the best bet is to ask how they frame, what kind of corners the build, how they attach partition walls etc.

I thought you had mentioned in other posts that you were doing DIY on some things, and air filtration is one of those things anyone can do given time. I bought myself an 18 volt Ryobi battery powered caulk gun (an absolute MUST for this job) and caulked every single place framing met sheathing on the insides of the walls, all the outside seams on the sheathing, the sill plate joins, the sill along the floor. Any place I could not get the caulk gun in, I used spray foam. I foamed around all the windows and doors. I had the band joist professionally done with 2#cc. Polyurethane caulk is best.

I used R21 Kraft backed Fiberglass batt insulation and installed it myself using every tip and criteria I could find online for proper installation. I taped all the seams. I don't think it is possible to hire someone who will be as meticulous as you will, doing your own insulation. If you can afford it, you can get someone to do spray foam or some combination of spray foam and cellulose or fiberglass, then you wont have to do much caulking. Combined with taping the seams on your outside insul board, you should have a very tight house.

-Rosalinda

Unless you intend to become an expert in sealing and want to diy or inspect carefully, it seems to me the first step is to spec that certain sealing steps are taken. second step is to spec for a blower test. If the blower test is great, you're set. If not, go back to caulking.