fire water runoff collection in IFC

[morgan.z]

In IFC , it states fire water runoff of 20 minutes will be collected along with other hazard liquid, if needed, while NFPA 30 is not in line with IFC at this point, it does not say 20 minutes .
Why only 20 minutes , not entire fire water design period? It puzzles me, i can not explain it away with client.
Please someone do me a favor to clarify this.

 

[cdafd]

See if some of this thread helps

Containment of fire water from fire sprinklers - NFPA (fire) Code Issues

We have a 100,000 sq ft building equipped with a dry pipe system designed to a density of .30 over 3,900 sq ft plus 500 gpm hose stream allowance. This design was a recommendation from FM Global about 12 years ago but the company is no longer an FM Global risk. Product stored is chemicals...

www.eng-tips.com

 

[cdafd]

Not an engineer or even close, plus, been forever since I have seen indoor flammable storage

Looking at NFPA 30 2024

Appears, depends on what you are dealing with, as far as design

I guess you have seen 16.8.1 and 16.8.2 is one example, appears you design to the design area of the sprinkler system.

So loving NFPA, appears you need to look in the standard for what you are dealing with, and find the secondary containment section, to see what it says about design,,,,

If you have to Design to NFPA, and not IFC

 

[UFT12]

Water containment for the entire duration of sprinkler systems, which can easily be 90 or 120 min for such occupancies, can be a nightmare to implement in terms of cost. So, jurisdictions or standards suggest a trade-off based on various facts. For instance, how likely is the system to run for the full duration? How fast can the Fire Department be on site etc.