Final answer:
For an I-Joist spanning 20 feet designed to an L/480 standard, the maximum floor deflection allowed is 0.5 inches.
Step-by-step explanation:
If an I-Joist spans 20 feet and is designed to an L/480 standard, the maximum allowable deflection in inches can be calculated using the formula: deflection = span length (L) divided by 480. To find the deflection in inches, we convert the span length from feet to inches by multiplying by 12 (as there are 12 inches in a foot) and then divide by 480.
Deflection = (20 feet x 12 inches/foot) / 480 = 240 inches / 480 = 0.5 inches.
Therefore, the floor is allowed to deflect up to 0.5 inches according to the L/480 deflection criterion.
An I-Joist is a type of engineered wood product used in construction. It is designed to span a certain distance without excessive deflection. In this case, the I-Joist spans 20 feet and is designed to meet the L/480 standard. L/480 stands for the allowable deflection limit, which is calculated by dividing the span by 480. So, the maximum allowable deflection for this I-Joist would be 20 feet / 480 = 0.0417 feet or approximately 0.5 inches.