Uploaded June 2020 | Updated September 2026, 3 hours ago
Mega Build Playlist: bit.ly/2zFd35V
We’ve finished framing the Project House, and now it’s time to put on the exterior sheathing.
TYPES OF SHEATHING
The home’s exterior sheathing, or “cladding”, is the material that the builder attaches to the exterior of the stud wall and on the roof rafters before the exterior finish and roofing material is attached.
Roof sheathing is also referred to as “decking” and builders almost always use 4 X 8 sheets of plywood or Oriented Strand Board (OSB) as decking material.
On the exterior, there are many sheathing options, using an interesting variety of materials. Examples of exterior sheathing products commonly used by builders in the U.S. are plywood, OSB, asphalt fiberboard, gypsum board, and rigid “foam board” (made from polystyrene, styrofoam or polyurethane). Plywood and OSB are the strongest and most durable, while the foam board products provide the greatest insulating value.
TechShield® RADIANT BARRIER ROOF SHEATHING
For the roof sheathing in the Project House, we’re using TechShield® “radiant barrier” OSB sheathing from LP. It is applied just like any other 4” X 8” OSB sheathing, but there’s one huge difference from standard OSB sheathing—one side of TechShield® is covered with aluminum foil, to provide an energy-saving radiant barrier that will reflect up to 97% of the sun’s heat and radiant energy reduce the temperature of our attic by up to 30 degrees on the hottest days.
The use of radiant barrier systems in home construction across the U.S.A. is growing at an exponential rate, and looking at results of some recent studies, it is easy to see why. Some studies, have found that installing radiant barrier reduced peak energy demand three times more than adding extra insulation in the attic. According to the Solar Energy Center, it is reasonable to expect that an attic radiant barrier can save 8-12 percent of annual cooling costs in the Southeastern United States, where the study was conducted.
Radiant barrier works by reflecting the sun’s radiant heat and not emitting that heat to the cooler surfaces around it. The effectiveness of a radiant barrier is determined by how much radiant heat it reflects and how little heat energy it transmits—a property called “emissivity”.
In milder weather, cool and gentle breezes may be blowing and outdoor air temperatures can feel quite comfortable—but even in this “perfect” weather, solar energy can really heat up your roof, insulation, attic and ceiling to temperatures that can make it uncomfortably warm inside.
Willamette Industries Oriented Strand Board Exterior Sheathing
Once the four walls of the frame are built, the next step is bolstering the strength of the frame. This is done using sheets of Oriented Strand Board or plywood. On our Mega Build, we used 4 X 8 X 7/16 sheets of OSB. OSB is an engineered wood product made of narrow strands of wood fiber that are oriented lengthwise and crosswise and bound in resin for increased strength. This “boxing” of the frame helps resist shearing and twisting forces better than it can without the reinforcement.
If you have the budget, go ahead and sheath the entire exterior of the house in OSB or plywood. In a high wind, or earthquake, the walls and roof take the brunt of the forces. A house that is fully sheathed with OSB or plywood will have excellent structural strength and will have very good resistance to “shear” or “racking” in high winds. Racking is the subtle side-to-side motion that can cause interior nail-pops and other damage in homes whose frames have not been properly braced.
Installing structural wood panels over roof and wall supports creates a diaphragm—like a “skin” that resists destructive forces.
OSB exterior sheathing also provides a solid base for the brick, stucco, stone, or whatever finish material you will use to complete your home’s exterior.
Tests by APA-The Engineered Wood Association, walls fully sheathed with OSB or plywood were three times stronger than walls constructed with gypsum wall sheathing or let-in bracing. Wood structural panels were significantly stronger than insulative paper-based sheathing. (Source: APA-The Engineered Wood Association).
Mega Build Playlist: bit.ly/2zFd35V
We’ve finished framing the Project House, and now it’s time to put on the exterior sheathing.
TYPES OF SHEATHING
The home’s exterior sheathing, or “cladding”, is the material that the builder attaches to the exterior of the stud wall and on the roof rafters before the exterior finish and roofing material is attached.
Roof sheathing is also referred to as “decking” and builders almost always use 4 X 8 sheets of plywood or Oriented Strand Board (OSB) as decking material.
On the exterior, there are many sheathing options, using an interesting variety of materials. Examples of exterior sheathing products commonly used by builders in the U.S. are plywood, OSB, asphalt fiberboard, gypsum board, and rigid “foam board” (made from polystyrene, styrofoam or polyurethane). Plywood and OSB are the strongest and most durable, while the foam board products provide the greatest insulating value.
TechShield® RADIANT BARRIER ROOF SHEATHING
For the roof sheathing in the Project House, we’re using TechShield® “radiant barrier” OSB sheathing from LP. It is applied just like any other 4” X 8” OSB sheathing, but there’s one huge difference from standard OSB sheathing—one side of TechShield® is covered with aluminum foil, to provide an energy-saving radiant barrier that will reflect up to 97% of the sun’s heat and radiant energy reduce the temperature of our attic by up to 30 degrees on the hottest days.
The use of radiant barrier systems in home construction across the U.S.A. is growing at an exponential rate, and looking at results of some recent studies, it is easy to see why. Some studies, have found that installing radiant barrier reduced peak energy demand three times more than adding extra insulation in the attic. According to the Solar Energy Center, it is reasonable to expect that an attic radiant barrier can save 8-12 percent of annual cooling costs in the Southeastern United States, where the study was conducted.
Radiant barrier works by reflecting the sun’s radiant heat and not emitting that heat to the cooler surfaces around it. The effectiveness of a radiant barrier is determined by how much radiant heat it reflects and how little heat energy it transmits—a property called “emissivity”.
In milder weather, cool and gentle breezes may be blowing and outdoor air temperatures can feel quite comfortable—but even in this “perfect” weather, solar energy can really heat up your roof, insulation, attic and ceiling to temperatures that can make it uncomfortably warm inside.
Willamette Industries Oriented Strand Board Exterior Sheathing
Once the four walls of the frame are built, the next step is bolstering the strength of the frame. This is done using sheets of Oriented Strand Board or plywood. On our Mega Build, we used 4 X 8 X 7/16 sheets of OSB. OSB is an engineered wood product made of narrow strands of wood fiber that are oriented lengthwise and crosswise and bound in resin for increased strength. This “boxing” of the frame helps resist shearing and twisting forces better than it can without the reinforcement.
If you have the budget, go ahead and sheath the entire exterior of the house in OSB or plywood. In a high wind, or earthquake, the walls and roof take the brunt of the forces. A house that is fully sheathed with OSB or plywood will have excellent structural strength and will have very good resistance to “shear” or “racking” in high winds. Racking is the subtle side-to-side motion that can cause interior nail-pops and other damage in homes whose frames have not been properly braced.
Installing structural wood panels over roof and wall supports creates a diaphragm—like a “skin” that resists destructive forces.
OSB exterior sheathing also provides a solid base for the brick, stucco, stone, or whatever finish material you will use to complete your home’s exterior.
Tests by APA-The Engineered Wood Association, walls fully sheathed with OSB or plywood were three times stronger than walls constructed with gypsum wall sheathing or let-in bracing. Wood structural panels were significantly stronger than insulative paper-based sheathing. (Source: APA-The Engineered Wood Association).
