We are having an discussion in my area with the Fire inspector. It is not really pertinent here to get into what that is because my question came up as a side note to it.
We have areas with a lot of Agricultural construction and no municipal water supply available. Fire uses the standard calculation for on site water storage based on NFPA 1142. As part of that calculation you must use the volume of the structure. What I am having trouble understanding is when they do the calculation and come up with a 10,000 gallon water storage requirement on a metal shade structure that has no walls. I understand that it may be used for covering wood or hay products, but it seems as though not having any walls would make calculating the structures volume kind of arbitrary. There would be too many ways of arguing what the volume is, i.e. total volume of the building materials, volume of the area under the roof from the lowest roof point to the highest, etc.
Has anyone else with this type of construction and rural setting come across this situation? If so, what was the decision made in regards to calculating water storage?
Thanks.