Beams in a house are fundamental structural elements, and while they are broadly referred to as "beams," they often have more specific names depending on their function, location, and the type of load they support. Understanding these specific terms is crucial for anyone involved in construction or home renovation.
Common Names for Beams in a House
Different types of beams serve distinct purposes within a home's structure, from supporting floors and roofs to spanning openings.
1. Joists
When a beam is specifically designed to support a floor or roof, it is referred to as a joist.
- Floor Joists: These run parallel to each other, forming the framework beneath floors. They transfer the weight of the floor, its occupants, and furnishings to the supporting walls or main beams.
- Roof Joists: Similar to floor joists, these support the roof structure, providing a surface for roofing materials.
- Function: Joists are horizontal structural members that typically run parallel to each other to support horizontal structures like floors, ceilings, and roofs. You can often see them in action during the construction of a deck or an unfinished basement ceiling.
- Materials: Joists are commonly made from engineered wood products (such as I-joists or laminated veneer lumber - LVL) or sometimes steel, chosen for their strength and stability.
2. Girders
A girder is a main horizontal support beam that spans long distances and supports other smaller beams or joists. Girders typically bear significant weight and transfer it to columns, posts, or foundation walls.
- Primary Supports: Girders act as the backbone of a floor or roof system, providing critical support for a large area.
- Material: Often made from heavy timber, steel, or reinforced concrete.
3. Headers or Lintels
These are beams used specifically to span over openings in walls, such as windows or doors.
- Load Distribution: A header (or lintel) distributes the weight from the wall above the opening to the framing on either side, preventing the wall from collapsing into the opening.
- Location: Found directly above window and door frames.
- Material: Usually made from wood (often multiple pieces nailed together for strength) or steel.
4. Rafters
While technically a type of beam, rafters are specifically the inclined beams that support the roof covering, running from the ridge of the roof down to the eaves.
- Roof Slope: Rafters determine the pitch and shape of the roof.
- Load Transfer: They transfer the weight of the roof (including snow and wind loads) down to the exterior walls.
5. Columns or Posts
Though not beams themselves, columns or posts are vertical structural elements that support beams or girders. They are crucial for transferring vertical loads down to the foundation.
- Support System: Beams rely on these vertical supports to carry the weight.
- Material: Can be wood, steel, or concrete.
Summary of Common Beam Types in a House
Here's a quick overview of the various names given to beams based on their role:
| Beam Type | Primary Function | Typical Location | Common Materials |
|---|---|---|---|
| Joist | Supports floors, ceilings, or roofs | Horizontal, parallel runs | Engineered wood, lumber, steel |
| Girder | Main support beam for joists or other structures | Major load-bearing spans | Heavy timber, steel, concrete |
| Header / Lintel | Spans openings (windows, doors) | Above windows and doors | Wood, steel |
| Rafter | Forms the framework and slope of a roof | Inclined from ridge to eaves | Lumber, engineered wood |
| Column / Post | Vertical support for beams and girders (not a beam) | Vertical, supporting horizontal members | Wood, steel, concrete |
Understanding these specific terms is important for effective communication in construction and for recognizing the various structural components that contribute to the integrity of a home. For more detailed information on structural components, you might consult resources like structural engineering guides.
