Sloping Slabs

[glennw]

In this post Gene and Joe were asking about sloped slabs.

There have been numerous requests over the years for similar functionality, with no really easy or accurate method available.

Soo...I thought I would have a play and I came up with this easy peasy way to achieve sloping slabs.

Basically:

Locate points at the corners of areas that are level zero.

Now, using something like a pyramid, set any heights that aren't a zero height to set the various negative heights as needed.

Using the Face tool go around the various planes and snap to your points.

The great thing is that the Face corners will snap not only to the points at zero height, but also to the top of the pyramids that area't at zero height, thus creating continuously joined 3D sloping planes.

You can then Extrude the faces to provide thickness to the planes.

In the attached picture I have left the pyramids visible for demonstration purposes - these would normally be deleted.

It sounds more complicated than it is.

This one only took a couple of minutes and has 2 height control points.

 

 

A simple shower stall needs only one height control point:

 

 

 

 

 

 

 

[GeneDavis]

Nice work, Glenn, and thanks.  Let's see you work out a solution for the surface of the bottom of such a troughed-to-drain slab, and then the perimeter edges, so we've all the surfaces of the garage slab modeled in 3D.  

[Joe_Carrick]

Since Glenn showed how it can be done - CA should be able to program it. 

[glennw]

3 hours ago, GeneDavis said:

Nice work, Glenn, and thanks.  Let's see you work out a solution for the surface of the bottom of such a troughed-to-drain slab, and then the perimeter edges, so we've all the surfaces of the garage slab modeled in 3D.  

Gene,

I got a bit lost with your explanation.

Can you explain a bit more.

I am happy to give it a go if I can understand what you are asking for.

 

Ah...do you mean that instead of the bottom of the slab following the top of the slab, you would like the underside of the slab to be level - which is the way you would build it on flat formwork or level ground?

[GeneDavis]

A contractor prepping that garage with the compacted gravel would never ever slope it, if he sloped it at all, to match the way the slab is screeded and troughed.

 

Look at the pic.  The away-from-door end is level, and is level until the trough begins its fall.  For a typical 20-foot slope falling 1/8 inch every 12, the slab top as it goes out the door atop the stemwall, is 2-1/2" lower than the level area.

 

The simplest way to build that gravel base is flat all across the full width at that unpitched end, then sloped full width to the door end.  Sections of the slab at sides of the trough end up thicker.

 

Is it really important for the software to have tools to model all this 3D with precision?  I can't answer that.  I wasn't one of those saying Chief needs to do sloped slabs.  I was entering the room to say that the sloped slabs I see done are always troughed as I drew one, so of we're going to get the tools, we need ways to represent how we build.

 

I've been fine using CAD and anno to spec these out on con docs.