highway6 wrote:Somebody correct me if I'm wrong...
but I believe your 107 contour is too close to your display. VERY wrong.
I believe you have to maintain the max slope there as well.... so if you normally have 5' circles to separate 1' grades, between the display and wrapping contour, you need 2.5' separation since it's 6" elevation change.
highway6 wrote:Not sure how your graphic proves me wrong, much less "Very Wrong". The section shown makes it quite clear.
In your first example, that describes exactly what I'm talking about. No, it does not.
In your 2nd example, the finished floor is 18" above the nearest contour..... No. Not at all. The nearest contour is AT the slab edge. 108 traces the edge of the display.Most people, including the original poster, show the finished floor 6" above the wrap-around contour... Yes, if the contour line traces the edge of the display.Placing a 107'-6" finished floor right adjacent to a 107 contour gets you a 6" cliff.. NO. That's not a "cliff". It's a slab 6" above grade.Placing it 6" away and only 6" above the contour line gets you 100% slope. Why would you do that?
To my understanding, the connection between contour and slab must still abide by the 2-20% slope. Yes, they should, and in my sections, they do.
highway6 wrote:I see now your 108 contour is right AT the slab. Still wrong in my opinion.
That's a 6" vertical drop off from slab to adjacent ground. Vertical drop off does not equal slope between 2-20%. Good freaking Lord! A slab edge is not grading.
By your interpretation, you could have 108 contour right AT the slab edge, and a finished floor anything above 108. Yep, but in this case NCARB requires 6" above surrounding grade.
If a 6" drop off is fine, why not a 6' or a 16' drop off ? ...because the program says 6". See below.
Also, to clarify, I'm not saying it has to be 2'-6" away. That is only the MIN. it can be away.. the 20%. On the other end, your 107 contour can't be more than 25' away from your 107'-6" slab as that would be your 2% slope.
Program
A steam engine Locomotive Display is to be located within a
fenced area in a city park. The park is surrounded by private
properties on all sides.
1. Place the Locomotive Display on the site within the
building limit lines.
Regrade the site to create a level area for the
Locomotive Display.
Indicate the finish floor elevation of the Locomotive
Display. The finish floor elevation must be 6” above
the nearest contour line.
2. Regrade the site so that water will flow around and
away from the Locomotive Display.
The slope of the regraded portions of the site shall be
at least 2 percent and no more than 20 percent.
Contour lines between property lines and building
limit lines may be manipulated.
3. The existing smokestack, rocks, and trees shall not
be disturbed.
4. Changes in site topography not required for proper
drainage should be avoided.
highway6 wrote:You make good points... That being said, I'm not just pulling this info out of my hiney.
In the Dorf videos, He explains it like I do.. He assumes the dirt is sloping up to the corner of the slab.. No, he did not.and he says you have to take into consideration the slope between last contour line and slab edge. Correct. The last contour line is AT the slab edge.
Do you still not understand the part about the slab being 6" ABOVE grade?
I'm just passing on the info from the Dorf Video and ultimately, I trust the Norman Dorf's video series and his interpretation over yours.You can deny basic geometry all you want. You'll still be wrong.
Fin.
To the original poster.. better safe than sorry.. keep your wrap around contour 2'-6" away as you know that will not be a wrong way to go about it. See the section cut above.
highway6 wrote:Yo Sparky..
I literally watched the video again less than 10 minutes ago before posting to verify that this video was where I learned that bit of information.
Here is a screen grab from the Dorf Video where he is discussing that it only has to be half the 5' circle away because the elevation difference is only 6"
I'm done with this..
People can either put it MIN 2'-6" away and be 100% sure they are not wrong (In case Dorf, the former grader of vignettes, is correct).. or they can listen to you and needlessly put it right up on the slab and not only potentially get the slope question wrong, but also sets up the chance where they might actually put one of those contour points inside/under the landmark (which would be very bad and very wrong).
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