More importantly, this option met with strong resistance from my framers-they had never done it before. If the notches are too deep or too wide, or the nailing is off, the wall won’t work as designed. One time-tested and code-honored option for walls without wood sheathing is 1×4, let-in wood braces, but they must be installed at the correct angle (45° to 60° from bottom to top plate) and fit with the precision of cabinet joinery to work properly. Diagonal metal bracing holds the walls square during construction. The author sheathed critical walls for additional strength and sheathed the gables to make siding easier. Structural connections for a strong wallĬorner hold-downs, long screws at top and bottom plates, and additional screws through top plates into the trusses complete the load path that keeps the house together during high winds and earthquakes. What I did may not apply to your project. Each building requires an individual braced-wall design strategy. This article is specific to my build, but the techniques are within the grasp of most builders and structural engineers in low-risk parts of the country and they can be adapted for two- and three-story homes. My design made things easier because it’s a single-story house, mostly square, and not in a hazard area-no hurricanes or earthquakes to complicate things. The code is cumbersome, and I had to lean on my friend Jay Crandell, PE, to help me, despite relying entirely on the prescriptive methods in the IRC. It takes a little head-scratching to design a braced-wall system that omits solid-wood panels. I counted twelve different braced-wall panel types in the IRC, ranging from let-in diagonal bracing, to wood sheathing and fiberboard, to gypsum wallboard. Nowadays, it’s also expensive.įortunately, the residential building code provides several methods to design and construct strong walls with various methods of bracing that add stiffness to the structure. Engineers refer to this as “load path.” Solid sheathing-or creating a rigid box with plywood or OSB on all the exterior walls-is a sturdy, simple, and forgiving way to achieve sufficient load-path connections and racking resistance. In other words, to avoid building a house of cards, your structure must have connections that transfer the gravity, wind, and earthquake loads from the roof, through the walls, and into the foundation. You also have to beef up the walls to prevent racking, which is when the house tilts laterally under the power of wind or earthquakes. Removing solid sheathing requires structural improvements to prevent wind from lifting the roof or pulling the house from its foundation. But I intended to omit OSB to save money. Many high-performance builders add continuous exterior foam over plywood or OSB sheathing foam insulating sheathing (like Zip R-Sheathing) is another option that makes installing continuous exterior insulation over sheathing a one-step pro cess. of R-5 foam with R-15 cavity insulation performs better than a 2×6 wall with R-19 cavity insulation. In addition to costing less than OSB or plywood at present, continuous exterior foam insulation slows thermal bridging through framing members, adds an R-value of R-4 or R-5 per inch, and simplifies vapor control. Recently I was able to solve all three problems and save a total of $2,755 on an affordable spec home I built. Sheathing a house without plywood or OSB involves three primary considerations: how to achieve resistance to uplift and racking, how to install siding without backing underneath, and how to get a warranty for windows installed on foam. centers sheathed with OSB shot up nearly 500%, and ready alternatives such as Zip System and Ox Thermo Ply were back-ordered. The price for building a 2×6 exterior wall on 24-in. I ’ll admit that my recent motivation to omit structural sheathing was cost. Builder and ICC-certified residential building inspector Fernando Pages Ruiz discusses how he omitted the OSB on this spec home to save money, while still making sure his build had reliable structural quality. Sheathing a house without plywood or OSB involves figuring out how to achieve resistance to uplift and racking, how to install siding without backing underneath, and how to get a warranty for windows installed on foam. Synopsis: The fluctuating cost of OSB and plywood can be a motivator when it comes to omitting structural sheathing.
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