7/27/2019 STUDIO_Rules of Thumb

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7/27/2019 STUDIO_Rules of Thumb

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a. Slabs spanning up to 24x 24 (i.e. 576 sq. ft.)

b. Thickness of the slab = span/30

3b. Floor structures / Slabs with one-way joist ribs:

a. slabs spanning from 12 to 30 in the direction of the deflection.

b. good for oblong bays

c. overall depth of slab plus joist ribs = span/20 + 2

d. common spacing of 20 and 30 between ribs

e. joists commonly have a width of 5 to 9

3c. Floor structures / Two-way spans:

a. Waffle slabs are used for 24 to 50 in the large dimension (maximum of 2500 sq. ft.)

b. Overall thickness of slab and joist rib = span/30 + 2

c. Rectangular modules have common linear dimensions of 2,3, 4, & 5

> helpful website: www.concreteonline.com

Rules of Thumb for Steel Construction

Depth (in inches) of Roof Beams and Joists = 0.5 x Length

Depth (in inches) of Floor Beams and Floor Joists = 0.6 x Length

Hinge or splice location for cantilever or continuous roof systems is 15% to 25% of

span length

Rules of Thumb for Joists

Floor joist thickness vs. span info from joist manufacturers:http://www.trulinetruss.com/html/floor_span_tables_-_ijoist.htm

http://www.trimjoist.com/spans.html

http://www.ufpi.com/PRODUCT/oj/prod/faq.htm

Rules of Thumb for Block Wall

A non-shared block wall is 3 5/8 brick + 1 air + 1 - 2 rigid insulation + 7 5/8 CMU

block + 1 airspace and drywall channel + drywall = 15 16 total wall

thickness from outside to inside.

More info on block wall construction:

http://www.maconline.org/tech/design/thinksystems/thinksystems.html

http://faculty.delhi.edu/hultendc/A220-Week2-Lecture-Web.htmlhttp://faculty.delhi.edu/hultendc/ARCH220-Main.htm