What is framing?

In construction engineering, framing means joining together pieces of members to build a whole structure. Framing is the step where the construction project starts taking its shape. Wood, engineered wood, and structural steel are some of the framing materials used in construction. The framing technique is divided into two types, lightweight framing, and heavyweight framing. In the heavyweight framing, the vertical supports are few, and the size and weight of the pieces to be used are more like timber framing, pole building framing, and steel framing. Lightweight framing has several smaller size vertical pieces like a balloon, platform, and light-steel framing.

Building a strong wood-dwelling that can efficiently withstand forces of nature is the major requirement in framing. A perfect framing design should meet the ever-changing design needs with an emphasis on optimization. It should also choose a design that involves less material use and induces sufficient strength to witness external loads. The framing structure thus constructed should be highly durable and offer superior stability. Advanced framing techniques help to overcome this. Advanced framing techniques use code permitted timbers, whose usability is optimized and mixed with engineering design and energy-saving methodologies. Conventional framing techniques do not achieve this. The advantages of advanced framing procedures ensure less lumber usage, minimized thermal bridging, and improved insulation.

Advanced framing methods

Stud spacing

According to codes, studs spacings should be maintained between 16 inches to 24 inches on-center. Studs up to 10 feet long can be spaced at a maximum spacing of 24 inches. $2 \times 4$ studs can be placed up to a spacing of 24 inches on-center for walls supporting roof and ceiling using utility-grade studs. These $2 \times 4$ studs can also be used at a spacing of 24 inches on-center, to support one floor, when utility-grade studs are not in requirement. 2$\times$6 studs spaced at 24 inches on-center are used for studs supporting a floor and a roof, instead of 2$\times$4 studs.
The 2$\times$6 stud advanced framing technique is used in areas experiencing extreme winters, and where the doors and windows occupy less than 10% of the total area.

Headers

Headers are the structural part of the framings built by joining two-stud corners, joists, and rafters. Two-stud corners make room to perform insulation, as these corners are fully accessible for air sealing and insulation purposes. Electricians can perform the snake wire around the corners when a right-sized two-stud construction approach is implemented. If a three-stud or four-stud approach is used instead of a two-stud, the insulation is replaced by a large thermal bridge which forms multiple cold spots caused by air leakage and condensation.

Headers are often constructed when necessary, this allows better insulation and wood saving during construction. For a better insulation, a $2\times 6$ ply can be used as a header. 

Additional methods such as foam sheathing is used to insulate headers. Foam sheathing is a kind of exterior insulation that uses foam to coat the exteriors. Most of the construction methods uses a $\frac{1}{2}$ inch foam that provides improved insulation and increases the R-value (thermal resistance value). For more insulation depending on needs, a higher thickness of the foam sheathing can be used. A $\frac{1}{2}$ inch foam sheathing provides resistance value of R-2 to R-3.5.

Double and single top plates

The single top plate is usually accepted in terms of the structural viewpoint when a plate needs to be used in combination with the in-line framing designs. This advanced framing design is widely accepted by various building codes such as International Code Council (ICC), and Building Officials Code Administrators (BOCA).

According to these codes, 20 gauge galvanized steel plates are used to join the single top plates at the corners of wall intersections. Nailing of these plats is done at each side. The area of the steel plates to be used must be 3$\times$6 inches.

The double top plates are used to chap the wood stud wall assembly, with overlapping in the corners and intersections.

Wall strapping

The strappings are used for the inner side of the wall exteriors and ceilings. These straps are installed perpendicular to the studs and rafters. They are used to provide support to the vapor barriers. Vapor barriers are used to isolate the air trapped inside the walls or seal voids in the walls, thus reducing the thermal conductivity.

Shoulders studs and cripples

Shoulders studs and cripples, preferably known as jacks are used when the metal hangers are structurally used to support headers. Avoiding jacks reduces the available nailing area which is required for siding.

Advantages of advanced framing techniques

Structural integrity

A properly constructed framing in strict adherence to design code guidelines provides superior thermal sheathing along with structural integrity.

Cost effectiveness

As advanced framing methods are fully optimized, they are less expensive as compared to conventional framing methods.

Sustainability

Advanced framing techniques using wood, are highly eco-friendly and account for less environmental damage as the methodology requires fewer materials.

Energy efficiency

Advanced framing techniques provide enough space for insulation thus minimizing air leakage and seal voids. It forms a wall structure having low thermal conductivity, thus minimizing thermal energy leakage.

Optimum value engineering (OVE)

Common Advanced Framing Details include optimum value engineering (OVE), a sub-branch of industrial engineering that specializes in minimum, or optimum material usage with minimized labor implementation including labor costs. Application of optimum value engineering by professionals requires specialized training and expertise. Some of the benefits of OVE are:

• Reduced construction costs.
• Maximum material usage.
• Reduced joists used in framing the structures.
• Better building insulation and sustainability.
• Reduces impractical and inefficient construction methods.
• Improved modules that save unnecessary cutting and wastage.

Context and Applications

The topic is taught in many undergraduate and postgraduate degree courses like:

• Bachelors of Technology in Civil Engineering
• Masters of Technology in Civil Engineering

Practice Problems

Q 1. What is the primary purpose of using a header?
a. Insulation
b. Structural integrity
c. Building durability
d. None of these

Answer: Option a
Explanation: The primary purpose of using studs is to provide better building insulation.

Q 2. For performing wiring and making insulation cavities which stud corner is best suited to serve the purpose?
a. Three-stud corner
b. Two-stud corner
c. Two-foot stud corner
d. Four-stud corner

Answer: Option b
Explanation: For wiring and making insulation cavities, the two-stud corner method is best suited.

Q 3. Which of the following sheathing technique is used to insulate a header?
a. Wood sheathing
b. Foam sheathing
c. Thermocouple sheathing
d. Both b and c

Answer: Option b
Explanation: For performing header insulation, foam sheathing is used.

Q 4. Which of the following is the objective of optimum value engineering?
a. Reduced material usage
b. Reduced material wastage
c. Reduced labor costs
d. All of these

Answer: Option d
Explanation: Some benefits of optimum value engineering are reduced material usage, reduced material wastage, and reduced labor costs.

Q 5. Which of the following is a benefit of using advanced framing techniques?
a. Improved energy efficiency
b. Cost-efficiency
c. Both a and b
d. None of these

Answer: Option c
Explanation: Cost efficiency and improved energy efficiency are two of the benefits of using advanced framing techniques.