2.3.5.  Create the roof slab of the first floor

In this step, you will create and place the slab on the roof of the Firtst floor, usig the tool Slab. It will has a thickness 0.20 (m), and it's bottom will be located at a height of 3.00, that is the base height of the walls of ground floor .

Open with AutoCAD Architecture the drawing, you created in the previous lesson, under the name h21190_groundFloor_openings, or if you wish you can download it by clicking here, unzip and open it.

In the first floor plan, draw with dotted line the polyline (mgD1Bm), which is the outline of the Attic slab, and the polyline (B1MEDB1) which is the outline of the hole that will open in the roof slab of the first floor to create the space for the attic, that you are going to create in next step (Fig. 2.3.6.1).
The roof slab of the first floor is in two levels, as shown in Fig. 2.3.6.0, and has as thickness 0.20 (m).

You will first use the first floor outline (kmghk) to draw the the roof slab, and then open in the slab the hole (B1MEDB1). You will then design the slab (BmgD1B), as shown in Fig.2.3.6.8, which is the floor slab of the attic and it is in a lower level. It is at the level of 2.20 m from the floor.

Fig.2.3.6.1 - First floor - Arrangement of the roof slab
h21190 firstFloor slabOutline mob800640

To Create the roof slab

With the tool Slab, you will use a closed polyline - the outline of the first floor - to create a single slab that has the properties of the tool (Slab) you selected.
After you create this object, you can then change its properties.

You can select the Slab tool on Ribbon > Home tab > Build panel > Roof Slab fly out menu (hover on ►)aca18 icon buildRoofSlab 9426 >select Slab, or for this example, you can select it from Tool palette - Design (Fig. 2.3.6.2).

 

  • Fig.2.3.6.2 - Tool Palette - Design
    toolPalet_designSlab t234388
  • Fig.2.3.6.3 - Tool Palette - Design - Slab
    aca18 thumbs designPalette slabLinework 480
  • Locate or design the closed polyline (kmghk), this is the outline of the first floor, at level 0.00 (Fig.2.3.6.1).
  • Open the Tool palettes- Design (Fig. 2.3.6.2) that contains the tool Slab - the slab you want to use - (you may have to scroll to display the desired tool).
  • Right click on the tool Slab, and click on Apply Tool Properties to ► Linework and Walls (Fig.2.3.6.3)
  • Select the closed polyline (kmghk), and press ENTER.
    It is possible to notice, that you can not select the polyline, because it overlaps with other objects. Use the Selection Cycling (status bar button), that controls the display behavior when you hover over or select an object that overlaps other objects. This button controls whether a badge or the Selection dialog box displays when you hover over or select an overlapping object. You can choose between overlapping objects by pressing Shift+Space or by using the Selection dialog box. Make sure that Selection Cycling is turned on. As you roll your cursor over objects, you will see an icon indicating that multiple objects are available for selection, from these objects select the  polyline.
  • Press n (No) to keep the polyline in the drawing.
  • For the Creation Mode: select p (Projected).
  • For Specify Base Height: type the value 3.00.
  • For the Specify Slab Justification: select Bottom.
  • At the prompt Select the pivot edge of the slab: select line (km) and press ENTER.
  • At the Properties palette of the slab that will appear,on category Dimensions locate tab Thickness (Fig.2.3.6.4), change it's value to 0.20 (it is, in meters, the width of the first floor slab), on category Location locate tab Elevation, change it's value to 3.00, and press Enter and Enter again.
  • Before you continue, open the Layer Properties Manager, select layer A-Slab that is created automatically with object slab, click on it's color and set it to 21.  (The only reason for editing this layer's color for slab, is to distinguish visually the slabs from the walls and other objects, while it is at conceptual view).
  • The slab of the basement floor has been created as shown in Fig. 2.3.6.5.
aca180 propSlab t325600
Fig.2.3.6.4 - Roof Slab - Properties
h21190 firstFloor 3dSlab 800533
Fig.2.3.6.5 - First floor 3DView - Roof Slab


The slab on the roof created as shown in Fig. 2.3.21.

Open a hole on the roof slab

The final shape of the roof slab of the first floor will be as shown in Fig.2.3.6.8. To do this, first you will create the hole (B1MEDB1) on the roof slab and then you will create a new slab at a height of 2.20, which will be the floor of the attic. For this reason, you have to lower wall (HG), changing it's height from 3.00 to 2.20. To do this select wall (HG), and on the properties palette that will open change it's Base height from 3.00 to 2.20.

To open the hole in the roof slab:
• Select the roof slab
• On Ribbon > on Modify panel > select Hole > and then select Add.
• At the prompt: Select closed polylines or connected solid objects to define holes : Select polyline (B1MEDB1), that is located on the floor (Fig.2.3.6.1), and press ENTER.
• At the prompt: Erase layout geometry? [Yes/No] <No>: Select No, (Pressing ENTER you select the default value that is No).
The hole on the roof created as you see in, (Fig. 2.3.6.6), press Esc to leave the command.

h21190 firstFloor 3dSlab 800533
Fig.2.3.6.6 - First floor 3DView - Roof Slab - Open a hole

Create the floor slab for the attic

The floor of the attic is at a height of 2.20 m from the level of the first floor (Fig.2.3.6.7), and has the outline (B1MEDB1), (Fig.2.3.6.1).
You have already drawn the polyline (BmgD1B), that is the outline of the attic, at level 0.00.

h21190 firstFloor 3dSlabSection 800291
Fig.2.3.6.7 - First floor - Section
  • Select the closed polyline (BmgD1B), that is the outline of the slab of the attic.
  • Open the Tool palettes- Design containing the tool slab you want to use and select it.
  • Right click on the tool Slab, and click on Apply Tool Properties to > Linework and Walls (Fig.2.3.6.3).
  • Select the closed polyline (BmgD1B) and press ENTER.
  • Press y (Yes) to keep the polyline in the drawing.
    For Creation Mode: select p (Projected).
    For the Specify Base Height: type the value 2.20.
  • For Specify Slab Justification: choose Bottom.
  • At the prompt Select the pivot edge of the slab: select line ( Bm) and press ENTER.
  • Select the slab, on the Properties Palette and in category Dimensions, define for Thickness = 0.20, for Elevation = 2.40, and press ENTER and then Esc.

The floor slab for the attic created as shown in Fig.2.3.6.8.

h21190 firstFloor 3dSlab 800533
Fig.2.3.6.8 - First floor 3DView - Roof Slabs