Drawing compound slope (Shower Pan)

I am trying to draw this shower pan (wedi Fundo Riolito neo, floor base, with channel drain). I can draw the basic box with 1/2" offset, but I cannot figure out how to draw it with the different slopes.

Here are the drawing specification (48" x 60" x 2 9/16").

I am just not sure how to start.
Do I draw lines on the face?
Then how do I get the slope.
I think the 2,3% means a 2.3% slope (maybe)?


You should be able to draw the outer rectangle and the inner rectangle and then connect the corners with the the line tool to make the valleys. You should be able to then push the drain rectangle down the right amount and it will all fold. Autofold might work, but the result may not be predictable if you don’t draw the valley lines first.

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Yes, it works when I tried it. I had to guess at the narrow dimension of the drain.

shower pan 20200820v17.skp (205.6 KB)

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You may want to start with only half the model. It is symmetrical and that will save you some work.

Draw the lower half of the rectangle.
Starting from each side edge draw construction lines ( with the ‘Protractor’ tool ) with the appropriate slopes:

  • the left one at 18.7:100 (up to the right)
  • the lower one at 12.3:100 (up to the screen top)
  • the right one at 2.3:100 (up to the left)

It’s a feature of the ‘Protractor’ tool.

That will give you the exact base along which you can draw your geometry.

Red, blue and purple are upright, G is at ridge height.

(I pictured this up but in fact all directions should be considered going down. The principale is the same though)

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There usually multiple ways to model anything in SketchUp.
This is how I would do this:


“Unfortunately” there are three different slope angles. ‘Follow Me’ leaves you with three sides with equal slopes.

I would just pulled the whole thing the same height and draw the slope lines and drain on top of it, select the drain part and move it down (⅜?) no need to worrie about slopes

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Ofourse if you start moving the indicated vertical face(s) the slopes will also change. But it isn’t the most accurate, nor most elegant way.
You need to create four accurate sloped faces that intersect and in the end have the channel drain brought in. I just mentioned the feature of the guides created by the ‘Protractor’. It’s something that is overlooked quite often. It is accurate from the start.

To me that sounds like OP is seeking for a way to create the slopes according to the drawing.
Just like @TheOnlyAaron was doing the machine parts, not to manufacture them.
So I was trying to help OP to get an accurate shape from his drawing information. Nothing wrong with that, I hope.
Eyeballing is certainly the easier way to achieve this.


That’s exactly how I did it. The amount down is 2 9/16 - 1 3/8" = 1 3/16" The width of the slot is the only dimension missing without needing any of the slope numbers at all.

This is how I did it. Make sure to move the drain down with the move tool not push pull.