drawing standards

[tclat]

Hi All,

I have come across two drawing standards for structural engineering plans.

1. For a framing plan the section is cut just below the floor looking up. That way, all the supporting beams are shown as solid lines and load bearing walls and their openings are shown clearly

2. For the same plan the section is cut above the floor looking down. That way the supporting beams and walls are shown as dashed lines.

I've tried using the former standard since it shows the supports more clearly and openings in load bearing walls are not lost. Where I work, there are more British/European trained architects who have an extremely hard time following through this standard.

Is one standard more North American while the other more European? Just want to know your thoughts on these.

Thanks

 

[TLHS]

I've personally never done the first method. If I want to show beams as solid lines I'll just call out a beam plan or something of that sort and indicate that the flooring isn't shown, or I will just show a little cut away piece of flooring on part of the plan to show that it's there.

I think I'd get pretty annoyed trying to work with a plan from the underside of the floor. You look down when you're reading drawings, so it seems more intuitive to have the plan views arranged as though you are looking down on the structure.

 

[woodman88]

I have always seen and use option 2, in California and Arizona. The floor plan cut 6" above the floor looking down.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[dik]

Option 1 was more common 40 or 50 years ago, and I haven't seen anything done using this for decades. Option 2 is common.

Dik

 

[ron9876]

I would say Option 2 is also how the people building the structure look at their work. They will ultimately be the people who use the drawings.

 

[Michel60]

Good afternoon tclat,
The most common conventions for me follows the construction type being used:
Steel frame - solid line for framing elements and deck edge, looking down
Concrete (masonry similar)- dotted line for beams/supports below floor, solid line for elements above floor, looking down
Light wood frame - dotted line for bearing walls below (usually I omit non-bearing partitions), solid line for floor framing and walls above, looking down.

Cut lines for the view typically at 3'to 4' above floor plane. Also occasionally I'll use a "poche" in the cut elements to bring some additional clarity or differentiation to what is being described.

regards,
Michel

 

[tclat]

Hi All,

Thanks for the responses.

I suppose the option 1 can be confusing since if I label a drawing "first floor framing plan" I show the ground floor walls and columns because that is the floor which supports it.

 

[hokie66]

Sections looking up are very uncommon, and are only used in the case of complex details which are difficult to represent in other views. No one likes to stand on their head to read drawings.

 

[BAretired]

I grew up with the first method. To me, it makes more sense but I realize that it could be confusing to those who are not familiar with it. Solid lines indicate bearing walls below or beams at the level being represented.

At one point, early in my career, I changed jobs and found that the drafters were not used to my system, so they resisted. For concrete jobs, we agreed to call them "forming plans" instead of "framing plans" so that you were looking at the form lines for the beams or walls on the floor in question.

For structural steel, it seems that a solid line is used to represent a steel beam on the framing plan. If it is the fifth floor framing plan, the solid line represents the steel beam on the fifth floor. On that point, everyone seems to be in agreement.

BA

 

[hokie66]

But what do you mean by "looking up"? The mirror image of the plan view? Convention on drawing line size, solid or dashed, etc. can vary, but plans are always drawn from the top. For concrete floors which are complex, it is common to have a profile plan showing the concrete formed dimensions, bottom and top reinforcement plans, and posttensioning plan if applicable.

 

[tclat]

BA.......the first option seems to make more sense to me as well but I'm constantly having to explain that the framing/forming plan shows the floor below (ie what supports it). I would generally show all bearing walls, beams and columns on this plan so to it is easy to follow the load transfer from slab to beam to column/wall. I'm always getting though, architects saying "hey, you have added a column or wall where we don't want it". I only show load bearing elements and leave out the partitions.

It seems some people show solid lines for structural steel. Don't you then show what supports this beam? What if it is a wall that doesn't continue through the floor above. Do you still show the beams solid but the walls hidden?

Hokie....the plans are actually drawn from the top....the term "looking up" only has to do with the drawing convention that the lines are drawn solid.

 

[msquared48]

I have always used the second method as if the floor diaphragm were not there, clearly noting the columns, bearing walls and shear walls below. That way, I can stack the Architectural and Structural plans in sequence to see if I have everything supported properly.

It's just how I learned to think in 3D and it works for me - kinda like 3D chess.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[hokie66]

Not any drawing convention that I am aware of. Anybody else think that is what "looking up" means?

As far as what is shown solid, dashed, shaded, cross-hatched, etc., that should be defined in a legend on the drawing.

 

[msquared48]

The only "looking up" drawings I have ever seen are Architects using their reflected ceiling plans. Need I say more?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[tclat]

Hokie,

I suppose "looking up" is not clear. The main question is whether the supporting elements are shown as solid (option 1) or hidden (option 2). Mike's way of describing it is probably clearer. Diaphragm not present so beams, columns and walls are shown as solid lines (Option 1).

 

[IsaacStructural]

My experience, in Chicago, is exclusively with the #2 method, can't remember every doing the #1st.

M.S. Structural Engineering
Licensed Structural Engineer and Licensed Professional Engineer (Illinois)

 

[hokie66]

I suppose it depends on how much information you want to cram onto one plan. For instance, for a steel structure supporting a concrete slab, I would provide a steel framing plan, then plans for the concrete. The steel framing plan has the steel beams solid, the concrete plan has them dashed.

 

[MiketheEngineer]

While #2 makes sense to me - ASK YOUR customer what they want!! or the Building Code Offical

 

[hokie66]

Mike,
Why would you do that? The engineer is the expert on how to present his design, not the client or the inspector.

 

[msquared48]

If we cannot understand what we have drawn, or get confused at the presentation, whatever it is, how can we expect anyone else to understand it? The horse must walk ahead of the cart.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com