Upload
dori
View
26
Download
0
Embed Size (px)
DESCRIPTION
Floor System Sizes and Materials. Lumber sizes. Common lengths 8’, 10’, 12’, 14’, 16’. Sill. Structurally graded according to knots (size, tightness, placement), wane, and straightness Must be pressure-treated lumber Used as a transition between masonry and standard lumber - PowerPoint PPT Presentation
Citation preview
Floor System Sizes and Materials
Lumber sizes
Common lengths8’, 10’, 12’, 14’, 16’
Sill Structurally graded according to knots (size, tightness,
placement), wane, and straightness Must be pressure-treated lumber Used as a transition between masonry and standard lumber
Anchor bolts embedded into masonry are commonly used to tie the sill to the foundation
Nails can be shot into concrete with a low-caliber nail gun
Joists
Provide support for floor Wood or steel
Joists
Size of wood joists depends upon Species of lumber Wood grade Spacing
12”, 16”, or 24” O.C. spacing is most common
Works with the 48” module common to plywood and OSB
Joists Recommended live load (40psf) Distance between supports (clear span) Joists manufacturer’s charts
Joists
Double joists must be provided under walls running parallel to the joist direction May be solid or built up of two joists May be solid or built up of two joists
Joists Bridging
May be used between joists Transfers the floor loads to adjacent joists Stiffens joists Aligns joists vertically May be diagonal wood members, metal or 1x3 wood cross
bridging May be solid blocking placed perpendicular between joists
Wood Floor Trusses May be used in place of solid lumber joists to provide support
for the floor Able to span longer distances than solid lumber joists
Reduce or eliminate the need for girders, piers, and columns Allow for designing open spaces Formed with top and bottom horizontal chords and diagonal
webs constructed of standard size lumbers
Wood Floor Trusses Typically placed 24” O.C. Open web construction
Reduces sound transmission through floors Aids in ease of plumbing, electrical, and heating systems
installation Sizes are determined from manufacturers’ charts
Wooden I-Joists
Similar to wood floor trusses May be used in place of solid lumber
joists to provide support for the floor I-joists are able to span longer
distances than solid lumber joists Speed construction Very straight May come with circular knock-outs
Wooden I-Joists Formed with horizontal wooden (solid lumber or micro lam) top
and bottom flanges, grooved to receive a solid plywood or OSB vertical web
Joist Header Used as rim joists with I-joist construction Can be used with truss construction Should be strapped to the sill in high wind areas Double under exterior walls parallel to joist direction
Girders (Beams)
Built-up Formed with solid lumber nailed together Built on the job
Glue laminated lumber (glulam) Solid, 1x__ lumber, glued together under pressure Graded according to appearance Very strong Able to span long distances
Girders (Beams)
Glulam (cont’d) Disadvantages
Weight Expense
Girders (Beams)
LVL (Laminated Veneer Lumber) Glued veneers, similar to plywood Advantages
High strength Long spans
Disadvantages Cost Low moisture resistance causes
delamination in high humidity
Girders (Beams)
PSL (Parallel Strand Lumber) Composed of veneers cut into strands Very strong Allows long spans
Girders (Beams)
Girder size Determined by
Type of material used Loads imposed Clear span of the girder
Where loads exceed material limits, the girder span must be reduced by using piers, piles, columns, or posts
Subflooring Provides a base for the underlayment and/or finish flooring
material Underlayment is material placed under finish floor coverings (i.e. as carpet,
to provide a smooth, clean surface) Underlayment can be combined with the subfloor into a single thickness Single thickness underlayment/subfloor is generally constructed of ¾”
tongue and groove plywood
Subflooring
Materials Tongue and Groove Plywood 4’x 8’
sheets speed the installation, glued and screwed.
Crawl Space Considerations
Access door is required Recommended size 24” wide x 18” high Large enough to allow for repair and/or
replacement of under-house mechanical systems
Ventilation provided Removes moisture from crawl space 8”x 16” vents are common