Distributed vs point load minimum specification

[MrBacco]

Hello, I was perusing the MA structural docs as shown in the attached image:

I'm trying to get my head wrapped around how to interpret uniform distributed vs point load. I understand distributed can be used to calculate total weight capacity of a room, and point load explains why I, a 200 lb person, can stand within a 1 sqft area. My confusion is to what extent (area) can I apply a point load? I suppose this level of detail starts to get into the actual structural design of the room ... Any help is much appreciated!

*Edit: in the above, I used the term point load interchangeably with concentrated

 

[OldDawgNewTricks]

Concentrated loads are typically applied uniformly over a 2.5 foot by 2.5 foot area unless otherwise specified (such as for vehicle barriers, etc.).

 

[phamENG]

When looking at decking or sheathing, 2.5ftx2.5ft as OldDawg mentioned is normal. I know a few engieners who prefer to do 1ftx1ft. When looking at a joist or beam or stringer, a point load is a point load.

 

[JStephen]

That 2.5'x2.5' is spelled out somewhere, it's not just assumption on the part of the user (it's in 4.4 in ASCE 7-16, for example).
The grating manufacturers have their own definition.
Edit: I see a separate definition for stair treads in 4.16.

 

[MrBacco]

Ah now I see it in the standard:

[tt]"Unless otherwise
specified, the indicated concentration shall be
assumed to be uniformly distributed on a floor or
roof over an area of 2.5 feet square [6.25 ft (0.58 2
m )] and shall be located so as to produce the 2
maximum load effects in the structural members."[/tt]

This kinda also answers another question I had regarding where exactly is the point load. If I'm reading the quote correctly, it would be in the worst possible location e.g. maybe in the center of a room away from a load-bearing wall.

 

[Tomfh]

That’s a large area for a point load. Real point loads are often much pointier than that.