Roof Deck Design

[oengineer]

I am new to the building industry and I have been tasked with designing a roof deck. The roof deck is for a school gym. Any suggestions and/or advice on how to proceed is appreciated.

 

[Celt83]

Many if not all of the deck manufacturers publish load tables for there roof decks usually indicating two values strength and load that produces L/240 deflection.

Additionally they all make reference to the Steel Deck Institute Manuals.

Open Source Structural Applications:

https://github.com/buddyd16/Structural-Engineering

 

[MotorCity]

Consider economy with regard to number of spans. Manufacturers list the allowable loads based on a one, two, or three span condition.

Designing for single span is conservative but not necessarily most economic.
I usually design for a two span condition because it has you covered for most conditions (such as at the end of the roof where you may have an oddball span).

Design for a three span condition if you're feeling lucky that you will actually get it installed in the field that way.

In any case, indicate on the drawings the minimum number of spans for the deck, and check pattern loading when using multiple spans.

1 1/2" deck seems pretty common for school work, but for automotive and industrial work we usually use 3" deck since it spans farther.

I prefer to use tek screws rather than puddle welds for attaching deck to supports, as screws are less sensitive to the quality of workmanship than puddle welds. Just personal preference.

Also, don't forget diaphragm loading, uplift, and component & cladding wind loads

Good Luck!

 

[Nor Cal SE]

I agree that 1-1/2" deck will probably be more than adequate, especially if your loads are not great. Do you have snow load in your location? If not, you'll likely find that 2-span condition gives you ample capacity for 1-1/2" and 18-gauge.

As MotorCity noted, your diaphragm capacity will determine frequency/arrangement of tek screws or puddle welds.