About Roofs and Slabs

Roof slab styles can contain more than one component, similar to wall styles; many of the conventions are therefore the same or similar. Roof slabs can also use roof slab edge styles.

Roof Slab Styles

Naming Convention:

Roof slab styles, like wall styles, include multiple components. The name should indicate the structure of the roof and the dimensions of the major components (minor components such as roofing felt can have the dimension omitted). The first component listed should be the major structural component. The last component should be the finish component (if any):

<Component name>-<Size in decimal units> + <Component name>-<Size in decimal units>...

Example Roof Slab Style Names:

Roof Slab Style Definition	Example Name
Roof Structure: 2x8 Rafter, roofing felt, asphalt shingles.	Rafter-7.25 + Shingles

Best Practices for Roof Slab Styles:

• Materials should be assigned to all roof slab components.
• Roof slabs should be defined with the baseline at the bottom of the major structural component.
• The index order of roof slab components should be indexed from top to bottom, with the top component having index 1.
• Thicknesses of components should always be positive. The thickness offset from the baseline should always be to the bottom edge of the component.
• You should consider classifying all roof slab styles to allow for more display control options.

Roof Slab Edge Styles

Roof slab edge styles are fairly simple and can contain a maximum of only two components: the fascia and the soffit. Unlike wall endcaps, roof slab edge styles are not applied to individual roof slab components, but to the roof slab as a whole.

Naming Conventions:

Roof slab edge styles should be named according to the fascia and/or soffit condition they define:

<Optional nominal fascia size> <Optional fascia> + <Optional nominal soffit size> <Optional soffit> - <Optional default edge cut condition> - <Optional edge overhang>

Example Roof Slab Edge Style Names:

Roof Slab Edge Style Description	Example Name
1x4 Fascia, no soffit, plumb cut, no overhang.	1x4 Fascia - Plumb
1x8 Fascia, 5/8” soffit, plumb cut, 1’ overhang.	1x8 Fascia + 5-8 Soffit - Plumb - Overhang 12
4x4 Cant strip edge style (for built-up roof).	4x4 Cant

Best Practices for Roof Slab Edge Styles:

• When creating the profiles for the edge, draw them for the right side of the roof when drawn in section.
• Exercise discretion when turning on “Auto-Adjust to Edge Height”. While this will cause the fascia to adjust to a variable width component in a roof slab as it changes thickness, the adjustment is proportional. The fascia will adjust both vertically and horizontally. The same consideration should be taken into account when turning on the option to adjust the soffit to the overhang depth.

Note: Roof slab edge styles can not be applied as a part of the roof slab style definition; instead you can apply them as a palette-based tool property. Many of the roof slab styles included in the sample content files that ship with AutoCAD Architecture 2021 toolset indicate in their names a specific roof slab edge style and when a tool is created from those styles, the slab style is already assigned to the tool properties. These styles originated in an earlier version of the software in which default roof slab edge styles could be assigned to a roof slab style. This capability was removed from the User Interface of the roof slab style editor, however the style properties were left in those sample styles.

Slab Styles

Naming Convention:

Slab styles, like wall styles, include multiple components. The name should indicate the structure of the slab and the dimensions of the major components (minor components such as vapor barriers, linoleum floor finishes, etc., can have the dimension omitted). The first component listed should be the major structural component. The last component should be the finish component (if any):

<Component name>-<Size in decimal units> + <Component name>-<Size in decimal units>...

Example Slab Style Names:

Slab Style Description	Example Name
Slab Structure: 6” Concrete, ceramic tile flooring.	Concrete-6 + Tile-Ceramic

Best Practices for Slab Styles:

• Materials should be assigned to all slab components.
• Slabs should be defined with the baseline at the bottom of the major structural component.
• The index order of slab components should be indexed from top to bottom, with the top component having index 1.
• Thicknesses of components should always be positive. The thickness offset from the baseline should always be to the bottom edge of the component.
• You should consider classifying all slab styles to allow for more display control options.

Slab Edge Styles

Slab edge styles are fairly simple and can contain a maximum of only two components: termed “fascia” and “soffit”. As with roof slab edge styles, slab edge styles are not applied to individual slab components, but to the slab as a whole.

Naming Conventions:

Slab edge styles should be named according to the fascia and/or soffit condition they define:

<Optional fascia size> <Optional fascia> + <Optional nominal soffit size> <Optional soffit> - <Optional default edge cut condition> - <Optional edge overhang>

Example Slab Edge Style Names:

Slab Edge Style Description	Example Name
6” Curb.	Curb
36” x 18” grade beam with brick lug.	36x18 Grade Beam + Brick Lug

Best Practices for Slab Edge Styles:

• When creating the profiles for the edge, draw them for the right side of the slab when drawn in section.
• Exercise discretion when turning on “Auto-Adjust to Edge Height”. While this will cause the fascia to adjust to a variable width component in a slab as it changes thickness, the adjustment is proportional. The fascia will adjust both vertically and horizontally. The same consideration should be taken into account when turning on the option to adjust the soffit to the overhang depth.

Note: Slab edge styles can not be applied as a part of the slab style definition; instead you can apply them as a palette-based tool property. Many of the slab styles included in the sample content files that ship with AutoCAD Architecture 2021 toolset indicate in their names a specific slab edge style and when a tool is created from those styles, the slab style is already assigned to the tool properties. These styles originated in an earlier version of the software in which default slab edge styles could be assigned to a slab style. This capability was removed from the User Interface of the slab style editor, however the style properties were left in those sample styles.

Palette-Based Roof Slab and Slab Tools

To apply a slab edge or roof slab edge style at the time of creation, you can specify them as default properties of a palette-based tool along with other properties:

• You may want to consider “Top”, “Bottom” or “Baseline” justification, depending upon the type of slab and its intended purpose.
• The Vertical Offset can be set to pre-determine an elevation for the slab.
• You can establish an edge style as a default.
  Attention: To pre-set the edge style, you must first specify the library drawing in which the edge style exists, then define the edge style to use. Even if the edge style already exists in the current drawing, it will not be used unless you specify the style location.

Slab tool properties, with a slab edge style set as the default.