Trusses are pre-fabricated, triangulated wooden structures used to support the roof. … You can span a large distance with a truss and the truss transmits all of the weight to the exterior walls. Therefore, none of the interior walls are “load-bearing,” so they can go anywhere and are easily moved later.
What are roof supports called?
A timber roof truss is a structural framework of timbers designed to bridge the space above a room and to provide support for a roof. Trusses usually occur at regular intervals, linked by longitudinal timbers such as purlins. The space between each truss is known as a bay.
How is a roof held up?
A truss is a prefabricated wooden structure that integrates a triangular webbing of structural members to provide support for the roof above while tying the outside walls of the house together.
What does a roof sit on?
The couple roof comprises two rafters leaning against each other, tied where they meet at the top. The rafters sit on a wall plate which is an efficient means of spreading the load exerted by the roof structure down through the walls without creating pressure points where each rafter meets the wall.
What are the 3 types of trusses?
Common types of roof truss
- King Post truss. A king post truss is typically used for short spans. …
- Queen Post truss. A queen post truss is typically a vertical upright with two triangles either side. …
- Fink truss. …
- Double Pitch Profile truss. …
- Mono Pitch Truss. …
- Scissor Truss (also known as Vaulted Truss) …
- Raised Tie Truss.
What is a roof void?
The roof void is the space beneath the roof structure and above the ceiling joists of the uppermost room or rooms in your home. The state of your a roof void can provide a picture of the age and condition of your house including the watertight condition of the roof coverings and flashings.
Are ceiling joists load bearing?
A joist is a horizontal structural member, running across an open space, that is used to transfer loads to vertical members, typically, floors & ceilings. … This is a sure sign that this wall is structural (load bearing). Most times, if the joists run parallel to the wall, the wall is non-load bearing.
Whats cheaper rafters or trusses?
Because they are usually pre-constructed off-site and brought to the job, trusses are faster and cheaper to install than rafters because they use smaller, cheaper pieces of lumber and rely upon multiple components to strengthen a unit rather than relying on weight-bearing rafters alone.
What is a four sided roof called?
A mansard roof is a four-sided roof with a double slope on each side forming a low-pitched roof. A mansard roof can help create extra living space. A garret is a full attic or living quarters that can be used.
What prevents rafters from spreading?
Rafter ties are installed between opposing rafters, and they should be installed as close as possible to the top plate. Rafter ties resist the outward thrust that rafters exert on the exterior walls. They help keep walls from spreading due to the weight of the roof. When the walls spread, the ridge board might sag.
Do rafters need blocking?
According to Section 6.3: “Rafters and ceiling joists having depth to thickness ratios exceeding 5:1 (e.g., 2×10) need blocking at their points of bearing to prevent rotation or displacing laterally from their intended position …
Does hip roof need collar ties?
A hip is stronger than a gable end. You don’t need any collar ties.
What are the top tiles on a roof called?
Eaves (or Top) Tiles.
What is the top beam of a roof called?
Top Chord. The top-most beams of a roof truss. In most common roof styles, these are the two slanted beams that hang over the side of a building.
Is the most common and widely used roofing material?
The most common residential roofing material used in the United States, asphalt shingles are popular because they are economical and easy to install. These shingles can be reinforced with fiberglass or organic materials (cellulose) without changing the appearance of the shingle.