Floor Limit L 360

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.

Floor limit l 360.

The l stands for length. They are expressed as a fraction. See the table below. Maximum deflection limits are set by building codes.

Note it gives the allowable deflection based on a fractional span quantity so a larger denominator will yield less deflection. Recent research has shown tile to fail under some conditions when the floor is more rigid than l 360. On center systems these floors often have deflection between the joists exceeding l 360. Clear span in inches l over a given number.

For example the allowable deflection of a 12ft span floor joist with plaster l 360 is 0 4 12ft divided by 360. They are expressed as a fraction. When building codes set a deflection limit such as l 360 they do so assuming that framing won t be subject to loads in excess of a certain amount. 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.

So if you have a beam 20ft long the allowable deflection limit is 20ftx12in ft 240 1. And since it is small i will leave the source for where it is found here 1. Maximum deflection limits are set by building codes. Please read everything on the attached photo below.