View Full Version : the break line in 2d dafted stairs

31st Aug 2012, 03:02 pm
I know that the direction of the line shows the direction of stairs?right?Can any one tell me how?and how do I know whether there are any stairs underneath or not?

31st Aug 2012, 03:05 pm
Can you show us a picture of what you are talking about?

31st Aug 2012, 03:35 pm
You would have a double break line. Any good architectural drafting/design book would have an example of what you are looking for.

31st Aug 2012, 03:38 pm
Actually I can't show any picture right now , but I'll try to explain more , What I meant by breakline was the diagonal line that you can see almost on every staircase in any 2D map .always the staircase is started with some stairs and then there is "the diagonal line" and then the next part of the staircase is shown in doted line.

31st Aug 2012, 03:46 pm
Thanks, but do you have any idea how can I determine the direction of stairs(going up or downwards)by the direction of the line?

Dana W
31st Aug 2012, 05:14 pm
The solid line shows the leading edge of the stair tread, and the dashed line shows the outside surface of the riser. The side the solid line is on is the down direction since the riser dashed line is under it, and needs to be recessed behind it somewhat.

Don't forget, on a floor plan, the stair drawing is merely a reference symbol. Keep dimensions, other than the wall locations off the stairs.

There is, or always should be an arrow drawn down the middle of the stair run showing direction, up or down, from the current floor (plan), and on the arrow there is usually a label "UP" or "DN".

On a floor plan, the convention is to show the location of the "beginning" of the stair by a line pair (solid & dashed) representing the position of the first tread & riser, then running repeated from there to a break line. The stair can be either up or down, but it must be labeled. The break line should always be there even if there is only one stair run in the well, simply because a floor plan is drawn as if it were viewed as a horizontal section cut through the building at 4 feet off the floor. That last point is something that is forgotten by some of the most experienced draftspeople.

A possible exception to the 4 foot convention is to account for landings. If there is a landing in the stair run, show its location relative to the walls or posts it will be supported by (or nearest to). Show landings only on the floor their supports are on. This means a stair run will always be shown UP to the landing. Then place your break line on or after the landing. Don't try to show the landing for the down run in the same well. Save that for the floorplan under the current one.

If two stairs are shown in the same well, one end will be UP from the current floor, and the other end will be down from the current floor, as in an over/under configuration on the first floor down to the basement and up to the second floor. Stop both of them with its own break line and leave empty space in the middle.

I 've never seen or bothered to draw any stairs shown with hidden lines under another stair. It is simply not relevent to the "current" floor plan. Leave the exact placement of stairs and openings to be shown on the stair section and detail drawings and floor framing plans.

1st Sep 2012, 05:00 pm
Dana thank you so much for your comprehensive answer , you helped me a lot. But still have some questions about your last 2 paragraphs.:(

1)"If two stairs are shown in the same well"could you explain this part?
2)And what I grasped from your last paragraph was that I shouldn't show any stairs (the treads) in hidden lines! should I? after the break line I will continue drawing the stairs in solid lines and this means that we have a section(opening) and therefore we are able to see the stairs under, if we are on basement floor will leave the part after breakline empty(because there arn't any stairs under) .Am I right?

Dana W
1st Sep 2012, 06:57 pm
OK, first off, we're talking about simple and straightforward stairs in your average single family residential house right?

your #2 is correct and pretty much explains #1, which is how you might have two stairs shown in the same stairwell. For instance, on the first floor, you would show a stair in one end of the stairwell going down to the basement, and show the other stair in the same stairwell, but going up to the second floor. Each one of these stair representations would be cut by a breakline so they don't interfere with each other. Also, don't worry about any ceiling structure separating the two stairs at this point. That goes on the details page(s) in the stair vertical section.

The only hidden stair lines you need on the floor plan are the lines to show the stair "riser", about an inch behind the solid line showing the edge of your tread. The only real purpose of showing the stair treads on a floor plan is to quickly identify the stair space on the plan.

Right, you never need to show stairs by hidden lines on a floorplan. There is just no need for that sort of detail on a floor plan. Save that for the details page. It is required in most areas where there are building codes, that the drawings include larger scale detailed plan and section views of the stair construction so you don't need to clutter up the floor plan with any of that. Floor plans are for locating the walls. Everything else is pretty much attached to them, so distances and limits are already set before the stairs, usually prebuilt offsite, even get delivered. Your responsibility as a draftsman is to make sure the walls will accomodate the required width and length of your stairs, and the required landing space at each end.

2nd Sep 2012, 03:05 pm
Thank you so much Dana.