Choosing wall and ceiling structural materials

Whether building a wall or a new ceiling, look into the different types of materials available today. Base the decision on how the materials affect the project’s cost, ease of installation, locale, structural needs, and environmental impact. Select between wood, steel, and PVC.

Wall studs : a wall’s framework

Wall studs separate rooms and spaces. The studs are the hidden framework of a wall upon which cladding materials such as drywall are attached. The width of the studs creates an empty cavity within the wall where mechanical, plumbing, and electrical systems can be hidden.

The cavity also allows for insulation where needed. Most of the time, interior stud walls are non-load bearing and are not structural members of the home. On the other hand, exterior wall studs are structural and are sized to support specific loads.

Types of wall studs

Standard wall studs extend from the bottom sill plate and extend to the top plate. Standard studs come in precut sizes for 8', 9', and 12' ceilings. Standard studs are spaced at either 16" or 24" vertically in the wall.

Trimmer studs are typically placed on each side of a door or a window opening to support the structural header beam that spans the opening. Trimmer studs may not always support a header, but are always wood members inserted into the openings within a wall.

Corner studs are three standard wall studs attached together to form the corner junction of two perpendicular walls. Corner studs are formed with two parallel studs while the third stud is positioned at a 90˚

Cripple or jack studs are vertical wall studs that do not extend full-length between the sill and the top plate. Some cripple studs support the horizontal window sill plates or fill spaces between the top of a header and the top plate. Cripple studs are also used for walls that are shorter than a standard height wall; i.e. referred to as “pony” or “knee” walls.

Size of wall studs

Exterior studs are structural and must house insulation and other building systems components. Therefore, the size of the exterior studs first is determined by the structural requirements of the home’s design. Most often, however, 2" x 6" studs are used for exterior walls.

The sizes of the interior studs are first determined by whether or not the studs will be structural components within the home. Most often 2" x 4"s are used for interior walls and are not load bearing. However, if the wall needs to be larger to make room for a mechanical systems ductwork, for example, it may need to be a 2" x 6" wall.

If the interior wall is structurally supporting parts of the building above, then the studs are likely to be larger than 2" x 4"s. Finally, if the wall is abnormally tall such as those used for double-height living room walls, the studs will again be larger than 2" x 4"s.

Pro Tip

During the planning phase of the project, research the building material to find out the exact sizes so that the construction planning will be as exact as possible.

For example, a nominal 2" x 4"solid pine wood stud is actually 1-1/2" x 3-1/2". In a similar manner, a nominal 2" x 4" metal stud is 1-5/8" x 3-1/2".

Ceiling joists

Steel joists have a heavier gauge metal plate material than metal studs.

 

  • Sizing :
    • The sizing of the joist is determined by the load it needs to bear. After calculating the total load amount, the sizes of the joists may be sized anywhere between 2" x 4"s and 2" x 12"s.
    • The spacing is usually 16"; though sometimes 12" spacing is needed if the ceiling is bearing particularly heavy materials or equipment above.
  • Use : Metal ceiling joists may be used for residential applications, but would need to be purchased through a builder’s supplier.

 

Solid wood joists, made of pine or fir, are most commonly used for residential applications. Pre-engineered wood joists are also available and come in a variety of different types.

 

  • Sizing: Same as steel joists.
  • Use:
    • Consult a professional to verify that the species and the size are adequate structural supports.
    • Wood ceiling joists are occasionally left exposed and treated for an aesthetic look. If the wood joists are left exposed, then the joists are usually wider that the standard 2". Likewise, a different type of wood may be used.

Choice of materials

Here are some aspects to consider when choosing the materials.
Criteria
General notes
Metal
Wood
Cost
  • The initial cost for any material is dependent upon the sizing of the material.
  • The cost of metal versus wood varies from time to time.
  • The total size of the project may affect the total cost of each material. For example, since metal studs require more tools, using wood for a smaller project might be more economical.
  • Lowest cost
  • Heavier gauge metal studs and joists costs more than lighter weight studs
  • Average cost
  • Inexpensive cost for tools
Environmental
  • Each material can be recycled or recyclable.
  • There is no clear-cut answer regarding which material is more environmentally-friendly than another as there are pros and cons to each.
  • Steel materials generally have recycled steel content.
  • Some steel members have more recycled content than others.
  • Generally takes a large amount of energy to manufacture.
  • Wood is not generally or as frequently re-used or reclaimed, but it is possible.
  • Pine is a rapidly renewable resource that largely uses solar energy to manufacture. The supply is quickly replenished.
  • Uses less energy to manufacture than steel.
  • Has a high insulation value.
Time of construction
Some homeowners may have a learning curve with metal studs that could prolong the project’s estimated length.
Metal studs have a reputation for reducing the construction time on a project.
  • More time and labor intensive than metal.
  • The learning curve is lower with wood and could therefore decrease the overall time spent on the project.
Sound transmittance
  • Sound transmittance may occur at any time regardless of the material selection.
  • To reduce sound transmittance, build a double layer wall and add insulation in between.
  • Sometimes additional insulation will be needed to extend through to the ceiling spaces and the wall may need to extend to the deck of the floor or roof above.
Metal may cause sound to transmit adversely.
Generally will dampen sounds and reduce transmittance.
Interior vs. exterior application
-
Metal studs can be used for either interior or exterior applications.
Wood studs can be used for either interior or exterior applications.
Load-bearing vs. non load-bearing
-
Metal studs can be used for either load bearing or non-load bearing applications.
Wood studs can be used for load bearing as well as for non-load bearing applications.
Criteria
General notes
Metal
Wood
Cost
  • The initial cost for any material is dependent upon the sizing of the material.
  • The cost of metal versus wood varies from time to time.
  • The total size of the project may affect the total cost of each material. For example, since metal studs require more tools, using wood for a smaller project might be more economical.
  • Lowest cost
  • Heavier gauge metal studs and joists costs more than lighter weight studs
  • Average cost
  • Inexpensive cost for tools
Environmental
  • Each material can be recycled or recyclable.
  • There is no clear-cut answer regarding which material is more environmentally-friendly than another as there are pros and cons to each.
  • Steel materials generally have recycled steel content.
  • Some steel members have more recycled content than others.
  • Generally takes a large amount of energy to manufacture.
  • Wood is not generally or as frequently re-used or reclaimed, but it is possible.
  • Pine is a rapidly renewable resource that largely uses solar energy to manufacture. The supply is quickly replenished.
  • Uses less energy to manufacture than steel.
  • Has a high insulation value.
Time of construction
Some homeowners may have a learning curve with metal studs that could prolong the project’s estimated length.
Metal studs have a reputation for reducing the construction time on a project.
  • More time and labor intensive than metal.
  • The learning curve is lower with wood and could therefore decrease the overall time spent on the project.
Sound transmittance
  • Sound transmittance may occur at any time regardless of the material selection.
  • To reduce sound transmittance, build a double layer wall and add insulation in between.
  • Sometimes additional insulation will be needed to extend through to the ceiling spaces and the wall may need to extend to the deck of the floor or roof above.
Metal may cause sound to transmit adversely.
Generally will dampen sounds and reduce transmittance.
Interior vs. exterior application
-
Metal studs can be used for either interior or exterior applications.
Wood studs can be used for either interior or exterior applications.
Load-bearing vs. non load-bearing
-
Metal studs can be used for either load bearing or non-load bearing applications.
Wood studs can be used for load bearing as well as for non-load bearing applications.

Rules to follow for proper planning

Use kiln-dried, not “green”, wood lumber for wall construction to prevent bowing.

If cutting treated wood, remember to protect the eyes and nose from ingesting the chemically-enhanced wood shavings.

If plastic-protected electrical wiring is strung through the knockout holes of metal studs, then it is recommended that plastic grommets are attached to the holes to protect the wiring from being accidentally cut by the sharp edges of the knockouts. Conversely, if electrical wiring is encased in metal sheathing, then no grommets are needed.

If the ceiling joists are designed to be exposed (rather than covered with drywall or acoustical tile), then the joists installed are usually wider that the standard 2" to provide a more aesthetic look.

Tips for installation before starting

Plan the construction project before purchasing supplies and beginning construction.

  • Take measurements at both ends of the new wall and at three spots in between when installing the studs.
  • Lay out the materials before assembly.
  • Make an effort to cut all the studs needed for the whole project at one time.
  • Finish materials attach smoothly to the plumb wall and ceiling structure. Use tools to verify that the structure is plumb.

Drilling holes into ceiling joists and wall studs guidelines

Before drilling holes into a joist or stud, refer to local building codes.

  • Holes in load bearing wall studs cannot exceed 40% of the width of the stud.
  • Notches (out of the side) of a load bearing stud cannot exceed 25% of the stud’s width.
  • Notches in non-load bearing walls cannot exceed 60% of the width of the stud.
  • The edge of a hole must be at least 5/8" from the edge of the stud.
  • Steel studs already have the knockouts so the guesswork is limited.

Tips for building the structure

Wood stud and joist construction tips

Framing wood stud walls can be constructed on the floor and then raised into place.

For non-load bearing walls, it is not necessary for the wood studs to be singular members within the wall. Therefore, parts of wood studs can be pieced together until they completely fill the gap between the sole plate and the bottom of the header.

To learn more, take a look at the DIY project Building an interior wall.

Metal stud and joist construction tips

The horizontal plates at the top and bottom of the wall are U-shaped tracks that C-shaped studs fit into. The edges of the track are then fastened to the edges of the studs with self-tapping screws.

Tools and equipment needed:

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