Sections

[MisterJingles]

Hi guys

Please bear with me on this question. Im having a heated discussion here in my office about sections through a building.
Ok, if I were to draw a cut section through a room, would I need to draw only what that cut line comes into contact with or would I need to show the window on the wall behind it too for example?

Sorry for such a simple question but I need to settle this.

Regards

[Tiger]

If the cut-line go through the house then yes, I would say that you need to draw the window as well. If the cut-line is just drawn say across the wall then yes, you just see the wall.

[ReMark]

Show what is behind a cut line or in front of a cut line? Everything in the direction of the cut line arrows should be shown whether the cut line passes through it or in front of it.

[MisterJingles]

Thanks Tiger.
Just to be clear, see the image below, if there were a window on the yellow wall it would need to be reflected in that section drawing?

http://i832.photobucket.com/albums/zz244/MisterJingles/Section.jpg

[Tiger]

Thanks Tiger.
Just to be clear, see the image below, if there were a window on the yellow wall it would need to be reflected in that section drawing?


Yes. ...............

[MisterJingles]

Thanks guys.

[eldon]

I have always understood that a section should only show what the section line cuts. The window would show on an internal elevation.

However, a sectional elevation would show both :D

[ReMark]

Then you would treat a sectional line cut through an object, like a piston rod, differently than you would one cut completely through a house?

[eldon]

Then you would treat a sectional line cut through an object, like a piston rod, differently than you would one cut completely through a house?

I am afraid that I have never drawn a piston rod, and as the OP mentioned a section line through a building, I was angling my response to be of use to him.

[Tiger]

I would perhaps only draw a representation of the window without all the trimmings and what-nots IF that is not what is important in the section. But I would get a slap from my old teachers if I removed it completely.

[ReMark]

The only way I would not show the window in this case is if my section line passed only through one wall or in the case of two walls (say one interior and one exterior) if I had two separate section symbols.

[eldon]

At the end of the day, it depends on what gives the required information, without being too concerned of the precise wordage of that part of the drawing.

[ReMark]

But we aren't talking "wordage" here. We're talking practical application.

[eldon]

But we aren't talking "wordage" here. We're talking practical application.

It probably depends on the general practice of a particular architectural company, so everyone is right, and everyone is wrong. I am afraid there is no definite answer, unless you would like to write a Wiki on it.

It also depends on ones laziness with words. Perhaps when someone says "section", they really mean "sectional elevation", but extra words that define the difference may not be uttered.

[ReMark]

Semantics.

[Tiger]

Semantics.

But isn't that what sparks the best discussions :thumbsup:

[eldon]

Perhaps you could agree, that if you were to show a window that was not cut by the section line, then you would show it as an internal elevation view :unsure:

[ReMark]

**Agreed.**

[Dana W]

I've spent some time working for a few building firms. Most times standard practice would be to show background items in a light line cursory representation for sections that cut entirely through objects, as in whole buildings or whole rooms. This helps the viewer orient to what they are being shown.

On the other hand, a detail section of a particular wall type would not show any background info at all. other than where the ceiling and floor intersect with the wall.

When there are complicated or artistic finish materials used on walls and doors, interior wall elevations will take care of presenting the information, complete with dimensions and finish schedule call-outs.

[ReMark]

If I were doing a whole house sectional view for a presentation I would show only the walls that I had cut through. All other "detail" would be left out.

[Dana W]

If I were doing a whole house sectional view for a presentation I would show only the walls that I had cut through. All other "detail" would be left out.

Believe me. After you've seen a concrete contractor holding a blueline drawing up to the sky (natures light table) and reading it through the back side in order to get "sitchee-ated" to the surveyors points, prior to pouring a reverse plan footing from an "As-Shown" plan, you would do anything in your power to make sure the viewer knew exactly in which direction a section view was presented.:lol:

[MisterJingles]

Well Im glad to see that it was not as simple as I was led to believe. I was taught to show only what is shown along the cut line and not what is behind it.
In fairness though it makes sense to show something on that back wall if its nature and position is not precisely reflected between all other views and elevations.

[ReMark]

I'm back at work today so I pulled my Architectural Drafting and Design book off the shelf, opened it to the chapter about drawing Sections and find that I am wrong. Yep, wrong. That's W R O N G. On page 717 (Chapter 35 - Section Layout) is a cross-section of an entire two story house and as pointed out by other (smarter) people the only elements shown are those that the cutting plane slices through. In this case that would be the exterior/interior walls, the foundation/footing, flooring, rafters, and joists. So I admit, one more time, I was wrong. Sorry to mislead you.

[Least]

A simple un-projected section would just show a slice through the cutting plain.

Sometimes we are asked to carry out projected sections and these would also show the extra elevational detail.

At least in the UK anyway.

[danellis]

It all comes down to what information you want the section to convey: If it's a presentational drawing you'd want the elevational details behind and maybe even hint at the tree you can see through the window. If it's a structural analysis drawing you'd peel it back to just be the outlines of the key elements. Other drawings would be somewhere in between.

dJE

[StykFacE]

To me, sections/elevations can be used for very specific situations depending, of course, on the situation. For instance, the room plan layout that was posted in the first page would make me believe that I was looking at a section, not an elevation, due to the section line cutting through the exterior walls with the flags on either side showing the viewing angle. This could, or could not, show the farthest wall since the section detail is vauge. I would have to refer to the detail to see exactly how the drafter has relayed the perspective of the section detail. It would not make sense to me if it were merely a section without the farthest wall shown, since it would be plenty of empty space in between each wall. Here's my thoughts on sections/elevations.....

If you want to show strictly the walls, I would section like this:
http://www.tannarzane.com/images_cadtutor/01-25-11/section_01.jpg

To show a section of the walls, including the farthest wall, you would use this detail. Notice the length of the tail is what constitutes the depth of the section/elevation.
http://www.tannarzane.com/images_cadtutor/01-25-11/section_02.jpg

Then there's an elevation detail. To me, you could use this deail to show both rooms. I've seen it done before.
http://www.tannarzane.com/images_cadtutor/01-25-11/section_03.jpg

That's my take on things at least. I know I have to generate lots of section/elevation views in the mechanical side of things, so I can get pretty detailed sometimes. 8)

[Dana W]

Well Im glad to see that it was not as simple as I was led to believe. I was taught to show only what is shown along the cut line and not what is behind it.
In fairness though it makes sense to show something on that back wall if its nature and position is not precisely reflected between all other views and elevations.
That is pretty much it. If you were to do a section through a perfectly symetrical house, something has to be done to show that the cutting plane has been oriented as was indicated on the plan view. Thus, a bedroom door in the background might be indicated with light lines merely for spacial orientation.

Whatever is shown will ultimately come down to what your boss wants on the paper.

[Tiger]

The most important thing in my opinion is that its clear and understandable by everyone that can be assumed to come in contact with the drawing. Right or wrong will always be debated, but at least make it clear what is what and where.

[Noahma]

I've spent some time working for a few building firms. Most times standard practice would be to show background items in a light line cursory representation for sections that cut entirely through objects, as in whole buildings or whole rooms. This helps the viewer orient to what they are being shown.

On the other hand, a detail section of a particular wall type would not show any background info at all. other than where the ceiling and floor intersect with the wall.

When there are complicated or artistic finish materials used on walls and doors, interior wall elevations will take care of presenting the information, complete with dimensions and finish schedule call-outs.

This is how we do the sections in our office. All relevant section cut information is on darker lines, while the background is on a light line. Our projects can be fairly complex, thus the addition of background beyond information comes in to play with understanding how the building is constructed in that particular area, and how it ties into the rest of the residence.

[Red333]

I'm a little late to the party, but i think it's important to show some info beyond the section line to give the contractor a sense of orientation. There are contractors that could understand the plans if they were written in Swahili and then there are contractors that want you to do everything short of swinging a hammer. Taking the time to show as much info on the drafting end ultimately saves time and money when it comes to construction.

[StykFacE]

Taking the time to show as much info on the drafting end ultimately saves time and money when it comes to construction.Not to mention your ass. :wink: