Exterior Deck for Commercial Freezer Unit

[L212]

I'm designing an exterior deck for a walk-in freezer unit for a restaurant. The existing building is a walkout (grade slopes from front to back about 9'). They want the freezer to sit on a deck at the rear of the building so that they can walk into it from the main floor. The freezer is about 15'x8'. The deck will only be for the freezer, no additional deck area for maintenance (I asked) or for any other sort of access. I haven't heard back yet from the supply company on weights but I am being told they think it's going to be around 4500# max when full. (We'll see how much that number goes up with the actual weight plus storage loading). With something that heavy I'd personally rather design a steel platform. However, the client of course is pushing for wood. I haven't run any numbers yet to see if I can even get it to work (for both gravity & wind/seismic) with wood within the area/depth parameters I'm given. But I've been searching the 2018 IBC to see if there's anything prohibiting any sort of commercial equipment on an exterior wood framed deck, so I can just hang my hat on that and go with steel from the beginning... But I'm not finding anything. I know it's allowed (and common) to put residential mechanical units on wood, but they're significantly lighter. And I know there's restrictions for interior wood platforms, but we're exterior. Anyone know of any restrictions/requirements for exterior commercial equipment that I might be missing?

 

[bugbus]

Freezers break down constantly and get very wet, something to be wary of

 

[phamENG]

gusmurr nailed it - water will be your enemy. Even properly insulated, there will be opportunities for water to get trapped between the unit and the deck, resulting in rot. I would push for a membrane system over top of the deck to protect it. Other than that, wood can work. I've designed wood platforms supporting 3 story houses before. A little freezer won't be an issue structurally. It's the rest of the stuff that could be an issue.

 

[EdStainless]

The Mfg should give you an installation layout that shows where they would need maintenance access.
And double the amount of material stored inside it that they tell you.
'Oh, we forgot about when we stock up for New Years', or whatever event.
What is the weather like?
The membrane sounds like a good idea.

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P.E. Metallurgy, consulting work welcomed