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Al Whitley/5 min read

Creating a Roof Plan in CAD 301: Tracing Roof Outlines and Adding Overhangs

Roof Plan Workflow

1

Trace Roof Outline

Polyline along the building's exterior wall lines.

2

Offset for Overhangs

Offset 12″ to 24″ outward for typical eave/rake overhangs.

3

Show Slope Direction

Pitch arrows pointing downhill from ridge to eave.

4

Annotate Pitch

Slope ratio (e.g., 4:12) labeled near the arrows.

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This AutoCAD tutorial walks through creating a roof plan in cad 301: tracing roof outlines and adding overhangs, covering essential tools and techniques for your projects.

Let's begin working on our roof plan. Now, if you would please make sure that you are in your CAD 301 plan model file, because we're going to have the roof plan information on top of the floor plan information. Let's go to layers, and let's slide down, and let's make the layer A-Roof Outline, our current layer.

And then if you would please, do a right-click on the mouse, choose "Select All but Current, " turn all of them off by clicking on top of an on light bulb, and then you can just click again to clear the screen, and then if you would please, turn on the A-Wall layer. With the A-Roof Outline, what we're going to be doing is we're going to be tracing a polyline around the building. So I'll go into my OSnap settings, I'll type OS, and I'll do a Clear All, turn on End Point, make sure it's turned on, and go OK, and then I will just draw a polyline, and I'll start at a corner, working my way around the building.

Make sure you go around the fireplace, and I'm just continuing around the building, making sure that I'm seeing it go to the endpoint. I'll click here, and then C to close. I'll draw a rectangle and go around the columns, and once again, a rectangle and go around the column here.

CTRL+S to save. We have our roof outline done. Now, you might be wondering, why is the line showing up dashed? The reason is that our A-Roof Outline has a hidden line type is defined within it, so when we imported the layers from the extraction model, we brought in the A-Roof Outline layer, and we brought in the layer characteristics.

You might also be wondering, why is the line type scale showing up? The Line type scale factor is 48 because if I go to Format, Line Type, you can see that our global line type scale factor is 48, calculated in the model space environment, so we do not have paper space units for scaling set. We have the outline. Now, if you look at the drawing, at your handout, you will notice that if you look at the dimensions in the top right-hand corner, that it's showing a 2-foot typical overhang.

This is where the roof overhangs the building. So again, we're talking to the framers, which is why we have our masonry layer turned off, so we're talking to the framers, and we're saying, let the overhang be 2 feet beyond the building. So I'll go to Offset, type 24, press ENTER, pick, and go out, press ENTER, CTRL+S to save.

But, you can see that right now, we don't show the roof overhang on top of the covered porch. So what I'm going to do is this. I'll draw a line from here to there, and I'll draw a line from here up to here.

I'll trim. These are the cutting edges. I'll pick there, pick there, and I'll also pick here.

So the line segment that was there will be joining those two entities. So I have that geometry done. But, if you look right in through here, you can see that we have the polyline that ends there, and we have this other line that's joining up with that.

It's really not clean CAD drafting to have a polyline that goes there, and another segment that starts there, because again, you can see right here how it looks. We have a couple of options. The one I'm going to recommend is I'll use Erase and delete those segments.

I'll choose this polyline, pick the grip with Ortho on, drag it horizontally, choose this grip, and drag it vertically. Hit Escape, CTRL+S to save. I’ll now trim using these endpoints and choose these entities.

So I've now trimmed them, and I have a clean intersection, CTRL+S to save. Now, what I'm also going to do is to make sure that this, in fact, is a closed polyline. I'll choose the polyline, right-click, go to Polyline, Edit Polyline.

I'll check the command prompt. It says "open, " right? Since it says open, that means that we have an open polyline. If I choose "open, " notice it now says "closed." Do you see what it did? How it got rid of that segment.

Whereas if I close it, the polyline is now a closed polyline. The last thing I want to do is to offset for the gutter. While I'm here, I'll go to Offset.

The distance of the gutter is three inches. I'll pick the line, go out, press ENTER, CTRL+S to save. So I have my outline of the building, I've cleaned up the polylines to reflect the overhang for the covered porch, but you can see that these entities are on the wrong layer.

I'll zoom in, select the inner rectangle, and map it to the A-Roof layer. And it's put onto a layer that's been turned off. That's fine, we're going to turn it on in a minute.

I'll select the other outline, and I'll migrate it to the A-Roof Gutter layer, which again is turned off. So it's fine, to an extent, saved. What we're going to be doing in a second is to start working on the hips and ridges for the roof itself.

So I'll go to Layers, turn on my A-Roof layer, and make it my current layer. I'll keep my gutter layer off for the time being. I can turn off my Roof Outline, I don’t need it.

And I'll turn off my A-Wall layer. So again, what we're working with now will be the actual roofs, hips, and ridges. So let me give you a few minutes to get this done, and then we’ll continue on.