Building Carla and Amber’s Houses: Layout to Dry In
Starting in October we began framing the first of two houses, Carla’s first and Amber’s second. When we left for Christmas break, Carla’s house had been dried in – meaning sealed from the elements – and Amber’s house was nearly ready for framing inspection.
We began both houses by laying out the walls. After first checking that the slab was correctly-sized we transferred the dimensions of the walls onto the concrete slab, using a chalkline to mark where the lines would go. We then cut top and bottom plates for each of the walls – marking for studs, doors, and windows – and numbering both the 2×4 plates and the position on the slab so we’d know where they went after they’d been built.
After all the thinking and measuring had been done we could begin the fun of wall building. Four of five different groups of locals, businesses, and schools came out to help us with walls on these two houses during October and November which was great: we would frequently split them into two crews working simultaneously, one hammering walls together and one raising them into place on the slab. Once they’d been raised, plumbed, and secured to the slab, the walls were tied together with an overlapping double top plate. This additional layer of 2×4 or 2×6 on top of the walls is one of many ways the individual framing members are strengthened through overlapping.
The next step was to sheathe the walls in OSB, a process akin to putting skin on the house. However, though the sheathing serves as a barrier it primarily functions as another connection between the wall studs and plates, providing enough strength for the walls to bear the trusses and roof load without bowing.
Once the OSB was nailed we began installing the trusses that would support the roof. My co-worker Alexander shot a neat time lapse video of us putting trusses on Carla’s house; it’s such a transformation after they’ve been raised. You can see me in the video (in the gray t-shirt) nailing them off. After they’re up and nailed to the walls the trusses are temporaily braced until they can be secured with sheathing of their own in the form of decking.
Just before we nail OSB decking being installed we build parapet walls – 4 foot walls that extend up past the level of the roof, as is customary to pueblo-style homes in Santa Fe. On the long sides of the house we used the vertical truss tails kind of like studs – by nailing 2×6 across the top we made short walls. For the ends of the house where there are no truss tails to use we built 4 foot high walls on the ground and lifted them into place. Once these walls were secured we added blocking to be used to nail the roof decking and exterior sheathing. Then it was time to cover the trusses in OSB, creating the flat (actually, slightly tapered) surface of the roof and enclosing the house in wood.
The next steps – which I don’t have photos of – include sheathing the parapet walls and installing rigid insulation on the roof before we hand the house off to the contractors who seal the roof using liquid asphalt and waterproof barrier. Then we come back and install windows and exterior doors so that the building envelope is sealed, making it possible to start interior work that cannot be exposed to precipitation.