Construction and Sheathing Techniques

Walls

• Studs are vertical columns supporting beams and joists, transmitting loads to the sill plate.
• Exterior studs are typically 2x6 or 2x4 and spaced 16 inches apart.
• Walls are constructed downwards and then lifted up for installation.
• Blocking (firestopping) is horizontal lumber used to prevent fire spread.
• Blocking is required between studs in walls taller than 10 feet.
• Walls are nailed to the subfloor for stability.
• Exterior walls are load bearing, while interior walls are non-load bearing.
• The bottom plate rests on the subfloor, while the top plate is at the top of the wall.
• Top plates overlap at corners and bearing wall intersections, providing structural integrity and acting as beams.
• Sheathing strengthens walls, provides lateral resistance, and acts as a base for siding and roofing.
• Structural sheathing provides support and strength.
• Non-structural sheathing provides insulation.

Sheathing Types

• Asphalt impregnated sheathing is moisture-resistant, made of wood fibers saturated with asphalt, providing weatherproofing and strength.
• Gypsum wallboard sheathing (GWB) is fire-resistant and moisture-resistant (used in bathrooms) and cannot rot.
• Oriented strand board sheathing (OSB) is a common and strong sheathing made from compressed wood strands and adhesives.
• Aspenite is similar to OSB but made with compressed aspen wood strands.

Corner Details

• Drywall clips connect drywall panels to the wall.
• Drywall is a board made from plaster, wood pulp, or other materials, used for interior walls.
• TYVEC air barrier and Zip system are types of impregnated air barrier sheathing.
• Corner details provide structural strength and weather resistance.
• Option 1 corner details are the most energy efficient.

Vapor Retarders

• Vapor retarders slow down moisture movement, preventing vapor from passing through walls, ceilings, and floors.
• Vapor retarders partially protect against moisture, unlike vapor barriers.
• Openings in buildings allow light, ventilation, and climate control.

Lintels and Headers

• Lintels are horizontal beams placed above windows and doors to support the wall above.
• Lintels are typically thick and made of stone, wood, or other materials.
• Insulated lintels help maintain consistent indoor temperatures by minimizing thermal bridging.

Ceilings and Roofs

• Pitched roof, shed roof, and flat roof are broad categories of roof types.
• Big overhangs protect the building envelope from water.
• The denominator of the slope ratio always stays at 12 inches.
• Flat roofs have low slopes.
• Conventional slopes are considered "v".
• Ceiling joists support ceilings.
• Floor joists are engineered wood designed to support 50 PSF.
• Rafters are sloping pieces of wood supporting the roof.

Roof Types

• Gable roof has two slopes that meet at a peak.
• Hip roof has four slopes that meet at the peak.
• Shed roof has a single slope.

Lookout

• Lookouts are horizontal supports for rafters.
• Cantilevers are required when the lookout is 12 inches or more.
• No cantilever is required with lookouts less than 12 inches.
• Roofing installation techniques, materials, and best practices are important.
• Roof openings include skylights, dormers, and chimneys.

Skylights

• Skylights should be installed parallel to the roof slope to prevent water accumulation.
• Curb mount skylights are raised above the roof.
• Framed-in-place skylights sit within the roof structure.

Dormers

• Dormer glazing is vertical.
• Gable dormers have two slopes and distribute loads to sidewalls.
• Shed dormers have a single slope and distribute weight to the top and front wall.

Chimneys

• Chimneys require a 2-inch gap for expansion and contraction.
• Saddles or crickets are built behind chimneys to divert water and debris.

Trusses

• Trusses support roof loads and are pre-engineered structures.
• Truss advantages include handling snow loads, quality control, reduced lumber waste, and faster installation.
• Truss plates connect truss members.
• Trusses sit on the top plates.
• The heel is the point where the truss connects to the top plate.
• Energy heel truss designs have increased space above the top plate.

Roof Sheathing

• Roof sheathing provides a nailing surface and lateral bracing for the roof.
• Sheathing is installed perpendicular to rafters for stability.
• Expansion and contraction gaps are left between sheathing panels.

Underlayment

• Underlayment is a secondary layer of protection against water damage.
• Asphalt felt is a traditional underlayment, while synthetic underlayment is more durable and often preferred.

Shingles

• Shingles are installed from the eaves upwards, with proper overlap.
• Drip edges are used to direct water away from walls.
• Shingles are machine-made and have a uniform appearance.
• Shakes are hand-split cedar with a more textured appearance.
• Shakes are thicker than shingles and offer durability.

Ice and Water Shield

• Ice and water shield is a protective barrier installed in vulnerable areas like valleys and around chimneys to prevent leaks.
• Valleys are the space between roof slopes where shingles overlap.

Roof Ventilation

• Ventilation is important for preventing moisture buildup in the attic.
• Ridge vents allow hot air to escape and maintain airflow.
• Intake vents bring in cool air from outside at the eaves, called soffit vents.
• Exhaust vents release warm humid air outside.
• Ventilation helps regulate temperature, prevent moisture buildup, reduce energy costs, and control ice damming.

Ice Damming

• Ice damming occurs when melting snow refreezes at the eaves, causing water to back up under shingles.
• Solutions include improving attic insulation and ventilation.

Roofing Materials

• Asphalt shingles are the most common roofing material and are made from fiberglass impregnated with asphalt and granules.
• Metal roofing is durable and often used in standing seam designs, which are crimped together for a watertight seal.
• Clay tiles are durable and aesthetically pleasing.
• Wood shingles are solid pieces of wood requiring proper installation and maintenance.

Other

• Attic knee walls support rafters in the roof and block off small spaces.
• Collar ties are used to reinforce rafters against outward forces.
• Roof joists keep the structure's walls from spreading at the base and support the ceiling.
• Cornice is the connection between the roof and sidewall, used for aesthetic installation .

Explore the fundamental aspects of wall construction and sheathing types. This quiz covers key concepts such as studs, blocking, load-bearing walls, and various sheathing materials. Test your knowledge on the structural integrity and installation processes involved in wall assembly.