Wooden Joists 1

[EnvEngg]

Hello,
I am an environmental engineer and not too familiar with structural design, but i need to solve a structural problem and needed help.
I need to calculate the safe loading capacity of the roof of a warehouse which is also used to store stuff.The plywood joists used are 2x8 at 16" on center.The span lenths are 14.6' and 24'
What design steps will i need to follow? Also, is it possible to look up codes and find the total live and dead load and assume that to be the safe loading?Thanks
Appreciate help!

 

[dicksewerrat]

Hire a structural engineer. If you miss one thing the bldg. could collapse. I wouldn't risk it.

 

[Ron]

Ditto on dicksewerrat's comment!

Too many things to consider if you haven't done it before.

 

[EnvEngg]

Hello,
Thanks for your replies. Just to clarify, the structure has already been constructed. My assignment is just to verify the approximate safe load carrying capacity of the roof as I do not have access to any calculations made earlier

 

[Ron]

In some respects, stating a "safe loading capacity" is more concerning than an original design. In this case you will be attesting to a load value that someone will believe as a limit, and since it is a warehouse, it could easily be achieved by hanging things from the roof structure.

If you are simply checking to see if the structure is reasonable, then that can be done with plenty of appropriate qualifiers or "weasel words". For instance, something like "...the roof structure was checked for structural capacity using an assumed dead load of X and an assumed live load of Y, was checked for a net wind load of W, and for snow loading of S (if in seismic zone, must also be checked for seismic load), and was found to have a capacity comparable to that expected for a structure of this type and age considering the codes in force at the time of construction.....this way you don't give a value since anything you give is going to be a guess when compared to the original design that you don't have.

 

[boo1]

check span table below

http://www.southernpine.com/tables/index.htm

http://www.apawood.org/