Structural framing plans (in plan view) 2

[Razorstructure]

Hi guys, Im a new draftsman working at a structural engineering/consulting company.
My boss tells me that in a frame plan, you have to show the walls underneath the floor your working on and show the structural members eg. beams, joists, etc.. from the floor above that your working on.

Is that true?? To me, it doesnt make sense, wouldnt you want to show the walls of the floor that your working on and the structural elements of the floor above eg.beams joists etc.... The other ways sounds too confusing.

Thanks

 

[Trenno]

I suggest finding a set of construction drawings in your office and going over them thoroughly. Do this a few more times. This way you'll know what the finished product should look like.

In the case of your question, say you are drawing the 2nd floor of a multi-storey building. You need to show walls/columns above AND below (shading will depend on your drafting standards), in addition you need to show all beams, slabs and other framing elements that are on the level in question, ie the 2nd level.

Showing beams ABOVE the floor your drawing makes no sense.

 

[dhengr]

Razorstructure:
Ah! One thing you’ll quickly learn is that the boss is always right. That is, until you become the boss, then you’ll discover that’s not always true, you just get all the blame when things go wrong. Architects tend to look at the floor plan like you are suggesting, they want to see the room they are in, including a reflected ceiling above, at times. Your boss is saying he wants to see the framing you are working on and he wants to see the structure below, that it will interact with, rest upon, be connected to, when it is erected. You also want to show things that relate to your framing right at that floor level, i.e. slab edges, floor openings, etc. Then, you further relate the framing you are working on and the levels below and above it with your details and cross sections, etc.

 

[Triangled]

Yes,
Structural peeps (I, having read the pub's guys/gals chat) want to see the floor and below to understand what's supporting the floor. Architectural peeps want to see the floor and above to understand how the space works.

 

[Triangled]

dhengr noted the other reason too! ;-)

 

[sponton]

@dhengr

Yeah, i've always hated that, it's really confusing

@razor..

Like dhengr said, that's the standard way engineers work, if you want to show a building plan of the second story, you have to show what the second level is erected on top of. That is the walls below, the beams that lie exactly at that level, basically a second level framing plan rather than being a third level floor plan (which is what architects would see it as and to a point what logic would suggest) is basically what you see when you're in the first level and look at the ceiling .

 

[steellion]

"3rd Floor Framing" on structural drawings refers to the structure supporting the 3rd Floor (i.e. the beams, columns, walls, etc. underneath if you were standing on the 3rd floor). Architecture and MEP "3rd Floor" drawings typically indicate what you can see if you're standing on the 3rd floor, so everything between the 3rd floor slab and 4th floor slab. Think about it building it: the structure will go first, so the contractor will see the slab on grade as the 1st floor, first elevated floor as 2nd floor, etc. By the time the arch/MEP finishes begin, the slab is complete, so the contractor will stand on the 2nd floor to fit out the 2nd floor. Hope that helps.

You have to follow the boss' lead though. There could be very good reasons to draft the way he wants it and is used to it that may not be immediately obvious to you, but it's based on real-world experience.

 

[spats]

The way I've always thought about it is that structural plan drawings are cut 1" above the floor elevation, whereas architectural plans are cut just above the window sills.

 

[dcarr82775]

Think about what the purpose of the plan is. A framing plan shows the framing that makes up the floor you are 'standing on'. Therefore you need to shows what is below. An architectural floor plan is used to build the walls you would see 'standing on' that floor so it only shows what is above. Three are some exceptions, but generally that is how they are drawn. Wood framing with offset bearing walls above and below becomes a mess and everyone handles that slightly differently.

 

[MotorCity]

From an erector's point of view, he does not really care about the walls supported on the floor (assuming its a concrete floor)unless there is some sort of miscellaneous framing or connections involved. Typically, only the top of walls are connected directly to the steel framing. This means that you are concerned with the walls below the steel framing.

For engineering purposes, the load from the walls supported on the beams is accounted for in the calculations and does not need to be reflected in the drawings.

For architects, its just the opposite. If you refer to a 3rd floor plan, it consists of the wall locations on the 3rd floor (i.e. above the 3rd floor framing plan).

 

[msquared48]

Typically, structural plans are numbered with the foundation first and the roof framing last since that is how the structure is erected.

However, when analyzing any structure, I always organize the sheets with re roof on top and foundation below so I can do a gravity load trace. I am always looking at the roof or floor framing with the structure directly below that is supporting it - bearing walls, beams, columns, shear walls, drag struts, etc.

Mike McCann, PE, SE (WA)

 

[dhengr]

Razorstructure:
You want your plans to cater to the people who will be using them and those who will be building, erecting, conc. forming, etc. off of them. Once the floor is sheathed or conc. formed and cast, the Arch. doesn’t give a ding what is below the slab, but the trades working off of your plans, at that level do. The Arch. is worried about walls, wall finishes, windows and doors and their openings, floor finishes in that room, etc. etc. He doesn’t care what supports the floor, but you must. You have already taken account of openings, concentrated loads, things which are above and which affect your structural design.

You should always be looking at your plans and details, as you develop them, and be asking yourself, ‘would the guy building this understand what is intended right here?’ If not, you need to be more specific, you need a x-section or a detail, some clarification. Don’t overdo the typical details, show them a few times at typical locations, otherwise they can clutter and confuse the issue. They are called typical for a reason, and are assumed to apply everywhere, expect where specifically directed otherwise. But, everyplace that typical detail changes to something else, you must make that change, and the new detail and its extent very clear for the workers, at that level. Show this change/condition on the level where the first actions to make this happen occur.

Sponton...., re: your 16FEB15, 15:31 post, 2nd para.... I would say it a little differently. Your cut is 1" above the floor elev., as Spats suggests, forget looking up at any ceilings, that’s where the confusion btwn. Archs. and Engrs. come in. You want to show what the worker will see, and needs to see, as he is starting to install the 2nd fl, framing, conc. forming, struct. stl. erection, etc., and what it will bear on, connect to, etc.

 

[steellion]

It would be 1" above the floor with a transparent slab

 

[msquared48]

There's another kind?

Mike McCann, PE, SE (WA)