How would you all model this sloped garage floor?

How would you all model this floor slab? It hurts my brain trying to figure out how to angle the floor face.
Garage Slope.skp (11.3 MB)

It helps if you add a screenshot as well as the model so we can see what you are dealing with without downloading 11mb of model. Some of us are on metered internet and so need to be selective on what they download.
Plus it may only need an image to be able to give an answer.
Not saying attaching the model isn’t the right thing, just that an image helps too.

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Does your local code allow for a step into the house rather than the curb around the parking area?

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Thanks. Me do that now:

I’m pretty sure it does, but in this circumstance that is actually a non-issue. The county does not have any inspections. You couldn’t get one if you tried unless it was a commercial job.

It’s the boonies.

Are there no foundation walls? Or the slab turn down at all?

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Well then, just make a single slope from back toward the overhead doors and have a comfortable step into the house.

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Indeed, that’s exactly what I was going for! However, it’s not the “what” it’s the “how”. I literally don’t know the best approach to drawing this yet. Hence the new topic.

In general, a pitched floor isn’t really any different from doing a pitched roof. The same thinking goes into each.

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Not sure what you mean by

But the foundation isn’t done yet. Neither is the roof nor the floor of the second level. There will be some foundation walls that will be about 18" wide x 24" deep, but I haven’t drawn those yet.

This would require you change elevations on the back porch, pedestrian door and overhead doors but in it’s simplest form would look something like this


For me, with a garage, the most typical condition is footings below frost and foundation walls that are level on top, with walls framed on top of them, while the slab is formed, with a slope, in between the walls.

A building like this that’s all slab on grade, can have the walls framed on the slab, but it usually thickens up as it turns down onto whatever foundation/grade beam you have at the perimeter. Then you’d have to have a depression in the slab to make the slope, and @Shep has made a pretty good representation of how that would look.


Yes, this is an interesting suggestion, and I’m actually realizing that the slope is a hard thing to accomplish because of a closet that the customer wants near the garage door, a detail that I accidentally missed in the original model upload. (updated now) I don’t personally want the step to be any higher than the code for a normal step,

Now I’m not as sure about the “what” or the “how”… :thinking:

I just had a super facepalm moment. The door is 9’ WIDE, not 9’ tall…

That simplifies the issue a bit.

Model all the stem walls and foundation and group. Then create a polygon against the stem wall in a separate group. Start with a line matching the height of the garage threshold and draw that line to the back stem wall at 2%. Draw a parallel line 4” below and close to make a face. Then pull it across the space adjusting for any intermediate walls or posts.

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You wanna post a gif?
:smiley: I’ll give that a shot but I don’t know if I understand all the instructions

I probably can’t for a day or two. I’m skiing the next two days.

Basically you are drawing 4 lines against the stem wall to create a profile of the slab. You then simply pull it across the space until you hit something like your closet (which should also have a stem wall in a garage). Then cut the slab to pass around it. If there is another bay on the other side of the closet wall, copy the section of the face you cut and paste it on the other side of the closet and continue to pull to the next wall. I always have garages with stepped doors, internal closet etc. you can also do this with the solid tools, but I prefer this method as it naturally places control joints where they should be.

Once you have this down, it takes just a few minutes to accurately model a sloped slab.


In other words, think in section: make a parallelogram shaped vertical face, and push-pull it out to make the solid. Another way to make a parallelogram is to draw a rectangle, and grab one vertical edge and move it up or down by the amount of total drop.


Last night while fiddling with @LinearGraphs model, I was about to repair the door swing on the rear door (some sort of compulsion). I noticed this odd behavior. In the gif below I’ll use single or double clicks with the select tool. No modifiers. I don’t know if this is an issue with the model, the plugin that created the walls (guess) or Sketchup.
arc parts

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That’s really weird. I’ll forward this to the developer.