Michigan Building Code Floor Joist Spans

Types of floor joists.

Michigan building code floor joist spans.

Depth span light medium heavy 8 10 to 14 85 1 27 10 14 to 16 88 1 44 2 04 10 18 to. Table r502 3 1 2 shall be used to determine the maximum allowable span of floor joists that support other areas of the building other than sleeping rooms and attics provided that the design live load does not exceed 40 pounds per square foot 1 92 kpa and the design dead load does not exceed 20 pounds per square foot 0 96 kpa. A floor joist appropriately selected to span 10 feet with an l 360 limit will deflect no more than 120 360 1 3 inches under maximum design loads. Span ft 1 5 2 0 2 5 3 0 3 5 2 30 22 18 15 13 4 59 44 36 30 25 6 89 67 53 44 38.

Joists for use in residential framing applications fall into two different categories. Tree sawed and engineered. Scientists and building code experts develop state of the art engineering data technology and standards on structural wood products for use by design professionals building officials and. Where guards are required outside joists and rim joists shall be a minimum length of 2x8 nominal.

1 courtesy of american wood council leesburg va joist span l l j see table 1 page 5. Additional support for the floor joists is achieved by nailing the ends of the joists into headers. For pitched roofs use the multipli. Span calculator for wood joists and rafters also available for the android os.

Ceiling joists should be added. Table r502 3 1 1 shall be used to determine the maximum allowable span of floor joists that support sleeping areas and attics that are accessed by means of a fixed stairway in accordance with section r311 7 provided that the design live load does not exceed 30 pounds per square foot 1 44 kpa and the design dead load does not exceed 20 pounds per square foot 0 96 kpa. The floor joist span chart and building code requirements are based on data from the 2012 international residential code using number 2 lumber. Ledger shall be a minimum of 2x8 nominal.

Depth is for open web joists. They are expressed as a fraction. State of michigan roofs section uip 4 roof cover roof structure roof cover roof structure built up rock rock hot mopped. Section r502 10 of the international residential code states that header joists can be the same size as the floor joists when the header joist span isn t greater than 4 feet but if the header joist span is more than 4 feet you ll need to double the header joist and ensure that it s capable of.

Simple span joists and rafters with uniform load. Maximum deflection limits are set by building codes. Clear span in inches l over a given number. Joist length prescriptively limited to 18 0 for footing design.