24" oc is not a "cheaper" solution, as in not as good of quality house...its simply a different and SLIGHTLY more energy efficient solution, depending on the details. True AF wants 1-2"+ of XPS sheathing, using either osb or cross strapping for shear bracing. Determining your ideal exterior insulation thickness depends on your climate zone, and how you want to handle interior wall condensation. Drywall clips, properly sized headers, etc are all part of the equation that the builder needs to do. AF is not intended to be mixed with 16" spacing. AF, using 2x6 walls, is structurally sound, assuming it is done correctly. Trusses align with 2x6, which align with floor structure, which carry the full point loads to your foundation. It does reduce the thermal bridging slightly in the walls, as well as replace some of the wood with more insulation. However IMO all houses in at least cool and cold climates should be using exterior XPS over whatever structural surface is in place, whether its osb over studs or no osb. I read these forums and too many people get caught up in R value and adding more insulation (actually most do not care about efficiency at all..."i am building efficient- 2x6 walls with batts! please........). Problem with that is, insulation is not an air barrier. Any air infiltration through your walls will give you an r-0 no matter how much you stuff in there. Design the shell to stop infiltration first, then worry about insulation. Affective products are sealed and taped exterior XPS, ZIP sheathing, osb sheathing with seamed primed and taped under a house wrap, and caulk. lots of caulk. Sill and head plates, studs to sheathing, outlets, etc. The spray foam guys like to tell you their product stops infiltration. While it does to a certain degree, it doesn't stop it at the sill and head plates, in or around headers, not to mention its very expensive. You can add exterior insulation which will give you more benefits for half the price. Focus on the shell first, insulation between studs 2nd. (however when you do, use a spray product, such as cellulose or fiberglass instead of batts) Back on topic, if done correctly AF can be just as strong and stable as 16 oc spacing. However do the math. Most cases, the $ in lumber savings is only a few hundred, like others said, the costs are offset in thicker drywall and more insulation. Trimming and attachement points are easier with 16" oc spacing, but thinking ahead in the design allows you to place blocking in walls for cabinets, closets, etc.

I have revisited this posting several times because I have been going back and forth trying to determine the pros and cons of a 15 versus 16 seer American Standard heat pump. We moved to Greenville, SC about two years ago knowing that we would be replacing our hvac system and duct work within a few years. We have a gas furnace and outdoor a/c that is about 22 years old. We have a reputable contractor and we have had the appropriate load calculation done. This thread has me stumped on which direction to go. We have a ranch style 2600 square foot home and we have no complaints about our humidity control in our home. With the current AS rebates the 16 seer 4-ton heat pump will be about the same cost as the 15 but I wondering if we want it. People prefer the latent humidity control of the 15 but why and what does that mean? I understand that the efficiency difference between the two is small. My main concern is the humidity control between the two systems. What is the difference between on demand humidity control on the thermostat versus the humidity control on the 16 seer AS model? Would having the first stage setting running more often than a 15 create more condensation on the coil and make us more susceptible to moisture/mold issues? If so, how do you know this? I spoke to someone today who had the 15 seer furnace and outdoor a/c and within two weeks asked for the contractor to upgrade them to the 16 seer because they said their home was too humid. He said he is in love with his system now. Can this experience be applied to the heatpumps? Thanks so much!!

R502.8.1 Sawn lumber. Notches in solid lumber joists, rafters and beams shall not exceed one-sixth of the depth of the member, shall not be longer than one-third of the depth of the member and shall not be located in the middle one-third of the span. Notches at the ends of the member shall not exceed one-fourth the depth of the member. The tension side of members 4 inches (102 mm) or greater in nominal thickness shall not be notched except at the ends of the members. The diameter of holes bored or cut into members shall not exceed one-third the depth of the member. Holes shall not be closer than 2 inches (51 mm) to the top or bottom of the member, or to any other hole located in the member. Where the member is also notched, the hole shall not be closer than 2 inches (51 mm) to the notch. From Notched Floor Joists - InterNACHI Inspection Forum http://www.nachi.org/forum/f23/notched-floor-joists-69169/#ixzz3DD6Jj5ha I'm seeing no sense in the added expense of material and time in using 8s instead of 6s.

I have found stud finders to be less than reliable There are two types of stud finders. The 'simple' ones are just a magnet that twitches when it gets close to a nail. Those are pretty reliable, but you are finding the nails, not the stud. The other type is electronic and I believe it detects the density of what it's placed on (or something like that). With those types, you usually choose the thickness of your drywall and then you can locate the exact edges of the studs. I've had great success with this type on drywall, but in my experience they don't work very well with plaster. Maybe the plaster/lath is too thick for the detector to differentiate between it and the stud? Or maybe I just didn't have a good enough stud finder.