Saturday, May 25, 2013

Three Minutes with Floor Sloping

I wrote a reply to a thread at the other day so this is really just an echo. In the context of choosing a method for sloping floor slabs (or roofs for that matter) see which approach best fits your current situation.

1) Slope Arrow - This is very effective when you know what sort of offset is required from known points but they are not necessarily at the start and end edges of the slab or in the same direction as any slab edge. Slope is defined by the location of the tail and head "endpoints" of the slope arrow. Revit will slope the entire floor according to the offset/slope parameter values you provide, between those points. It is perhaps the most versatile method other than shape editing but it is also a bit harder to become comfortable with.

2) Define one edge as slope defining - This is very easy for slabs that slope consistently overall in one direction, from one edge, and you don't really care where the other edge "ends up", it is what it is. You just pick one edge, set a slope. It is just like roofs except we are limited to one edge defining slope with floors.

3) Defines Constant Height - This too is very easy when the start and end edges of the slab also define the floor's lowest and highest elevations (and what we see as the slope value isn't the priority). You just set two parallel floor sketch lines to the appropriate elevation values, whatever values define the required offset.

Fwiw, for structural floors/roofs - Pick Supports (shape editing) - This will slope a roof according to the structural elements you select.

I took a few minutes to record a video of each approach, embedded here. It also touches on using the cantilever settings to extend the edges of a floor slab beyond the structural support members.


Justin said...

any idea how to make a variable thickness floor over sloping structural system?
Case: I have a roof built on sloping structural element to provide an overall slope, then adding crickets to provide localized slope in different directions (foam layer in roof is variable thickness).

The problem I run into is that if I slope the floor, I cannot use the "modify sub elements" tools to create crickets. On the other hand I cannot create a floor on a sloping reference plane (though I can pick sloping structural support).

Steve said...

Justin - Probably a combination of both techniques. Use a slope floor for the largest consistent volumes you can. Then use separate floors and shape editing to fine tune other locations. Use join geometry to get the floors to look as if they are one volume.