Mariog,

Thanks for your reply.

I am using the formula you mention earlier for A and I am getting very low number for A.

Please check my input..
1. D = 27 feet
2. Pi = 2.5 Psi
3. Dlr = 4594 lb + 200 lb (for noz attachment) (weight of roof=4594 lb with 0.1875 in thickness)
4. FY= min Yield st = 25,000 Psi for 304L
5. Tan25 = 0.4663

I am getting A=0.06 in^2??

Please check my units for DLR and let me know, what I need to correct.

I appreciate your input and time.

Regards,
Mayur