Framing

I-Joists

I-joists are engineered wood systems that support the main floor. I-Joists are designed to be straighter, stiffer, stronger and more consistent in performance than solid sawn lumber joists. The wood used is re-engineered in a sophisticated manufacturing process to produce a product that outperforms traditional lumber.

On top of the I-joists goes the oriented strand board (OSB) floor decking. The flooring edges are tongue and groove joints.

The floor framing is connected with bolts from the foundation to the sill plate. The I-joists and rim joists are then nailed to the sill plate, and in turn, the OSB floor decking is nailed to the joists and rim joists.

In addition, there is a variety of steel hardware designed to connect the framing to the foundation. The engineer specifies this hardware (such as foundation straps) to suit the design of the house.

Wall Framing

Most of the studs are "finger-jointed." Finger-jointed studs are ideal for use in single home construction, and provide significant benefits. For studs, straightness is a very important characteristic. Finger-jointed studs are straight and dimensionally stable because they are manufactured from short pieces of kiln-dried lumber – trims from the sawmill operation. Walls built with finger-jointed studs are straighter, even when subjected to heat or humidity. This helps eliminate nail pops in drywall and other related wall problems, resulting in fewer costly callbacks. Furthermore, time is saved by not having to sort through warped studs, and valuable lumber is saved by using smaller pieces that would have otherwise gone to waste.

Using OSB wall sheathing adds rigidity - you may have seen diagonal pieces used at the corners of older homes (built before plywood and OSB were widely available). The OSB does the same thing, but it provides much more strength.

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Building wrap

When walls are built, they are covered in a building wrap as a standard construction practice. Building wrap acts like a windbreaker that is wrapped over the sheathing and under the exterior siding. It is then cut out around windows and doors. The building then resists water intrusion, and thus makes for a more comfortable, energy-efficient home.

Floor Trusses

The upper floor is built with floor trusses. We use floor trusses because they provide longer, stronger clear spans and greater design flexibility in locating bearing walls and partitions on the main floor. Because the floor truss system can be spaced farther apart, fewer are needed. They can be built to exact lengths in the shop and delivered to the job site ready for installation. The lightweight, rigid floor trusses go up easily and quickly, often without the use of a crane.

Roof Trusses

Our homes use roof trusses for the roof framing. Trusses are pre-fabricated, triangulated wooden structures used to support the roof and have a number of significant advantages, such as strength, efficiency, and flexibility to span longer distances.

Roof trusses come in several standard configurations: "W" truss, "M" truss or "scissor" truss. Each performs a different task. "Gable" trusses are used at the ends of the roof (the outermost trusses on either end). The vertical pieces are 16 inches on center so that siding can be nailed to them. The trusses are attached to the walls with small metal plates.

Once the trusses are up, the roof is covered in roofing OSB, which gives the roof tremendous rigidity.

Once roof sheathing has been completed, it is covered by roofing felt (sometimes referred to as "tar paper" or "building paper"). Roofing felt acts as a waterproof barrier between the sheathing and roofing material. We apply the roofing felt to the clean surface shortly after sheathing is completed to protect it from weather.

Truss Uplift/Partition Separation

Some homes may experience a separation or gap where the ceiling meets the wall in certain areas on the upper floor. This is not a cause for panic nor is it a defect in your home. It is a phenomenon known in the building industry as truss uplift (sometimes referred to as partition separation). It is common in homes built with roof trusses instead of rafters.

If a house suffers from truss uplift, the top floor ceilings literally lift off the interior walls in the winter and drop back down in the summer. At first glance, one might assume that the floors have settled. Actually, the ceiling has gone up - sometimes creating a gap of as much as two inches where interior walls meet the ceilings. Typically, when truss uplift happens, it is most dramatic the first year after the home is built and decreases with time.

Why Truss Uplift?

The way in which houses are built has changed over the years. Attics of newer houses have more insulation and ventilation. They also have roof trusses instead of rafters and ceiling joists.

The bottom chord of a truss is buried below a deep blanket of insulation. Even on the coldest days the bottom chord is insulated and warm. In such cases, it is also contracting. The top chords are doing just the opposite because they are above the insulation, they absorb moisture from the air, which causes them to elongate.

With the top chords growing and the bottom chord shrinking, the truss arches upward in the middle, causing the ceilings to lift off the walls. In the summer, this cycle reverses itself.

Examples of Truss Uplift