What is joist seat depth?
Joist Seats for Nominally Flat Roofs: For a nominally flat roof (roof with a pitch less than or equal to ¼” per foot), the minimum seat depth required by the Steel Joist Institute (SJI), is 2 ½” for K-series joists and 5” for LH-series joists.
What is the difference between a joist and a joist girder?
A joist and a girder are both types of beams. The term “beam” is a general, all-encompassing term that refers to a structural member in a structure that supports a roof or floor above it. A girder is the main load-bearing beam in a structure and is supported by posts. Joist is a structural member supported by beams.
What is joist girder?
A joist girder is a simple span, supporting equally spaced concentrated loads from open-web steel joists. These concentrated loads are considered to act at the panel points of the joist girder. Joist girders are designed to allow for the efficient use of steel in longer spans.
What is the standard depth range for deep Longspan joists?
As with LH-Series joists, DLH-Series (Deep Longspan) joists are for longer span conditions and support larger loads. With standardized depths from 52” through 120” and spans up through 240 feet, DLH joists also allow for special profiles to accommodate a variety of conditions.
What is joist camber?
To compensate for deflections, structural steel beams and joists may be fabricated with a slight upward curvature, commonly referred to as camber. Cambering.
How do you read a joist designation?
The K-Series, LH-Series and DLH-Series standard joist designations shall be established by their nominal depth, followed by the letters K, LH or DLH as appropriate, and then by the Section Number designation assigned. The Section Number designations shall range from 01 to 25.
What is a girder in framing?
Girder—A load-bearing horizontal framing member (beam). In this case it. supports the load from the floor above it. Post—A vertical support member that often helps to carry the girder.
What joist means?
Definition of joist : any of the small timbers or metal beams ranged parallel from wall to wall in a structure to support a floor or ceiling.
What is floor girder?
A horizontal solid wood structural member used to support and stabilize floor joists along their length. Girders used in lumber floor assemblies are site fabricated typically using multiple pieces of 2 x 10 or 2 x 12 lumber nailed together.
What is LH joist?
Longspan (LH) and Deep Longspan (DLH) Steel Joists are relatively light weight shop-manufactured steel trusses used in the direct support of floor or roof slabs or decks between walls, beams, and main structural members.
What is K-series joist?
A Top Chord Extension or Extended End, K-series, shall be a joist accessory that shall be designed in accordance with this Specification to support uniform loads when one or both ends of an underslung joist needs to be cantilevered beyond its bearing seat.
What is a joist chord?
Double-Pitched Top Chord Joists Have Double-Pitched Top Chords With The Ridge At The Centerline And A Straight Bottom Chord With A Modified Warren Web Configuration. The Pitch Is Constant From The Bearing Points To The Ridge With The Maximum Depth At The Centerline.
What is the minimum camber?
¾ inch
When specifying camber, the follow- ing general rules of thumb should be considered: Only specify camber when ¾ inch or more is required, and work in ¼-inch increments. Cambers smaller than ¾ inch generally are hard to induce. Don’t camber beams shorter than 24 feet long.
What is a joist tag?
A joist tag is a metal label wired to each joist during fabrication that provides information such as the manufacturer’s name, job number, mark number, plant location, and date; an example is shown in Figure 3.
How thick should a girder be?
Assuming an 8.5-inch composite deck and 2 inch haunch, the minimum steel plate girder depth will be = 67.2 inches – 10.5 inches = 56.7 inches; assuming a minimum top flange of 1 inch and a bottom flange of 1 ½ inches, the minimum web depth will be close to 54 inches.
What size is a girder?
Girder spans also range from 15 feet to 45 feet in 5-foot increments for each of the beam spans noted.
Why is it called a joist?
Joist comes from the Old French word giste, “beam supporting a bridge,” from the Latin iacere, “to rest.” joist that receives the end of a header in floor or roof framing in order to leave an opening for a staircase or chimney etc.