Flat Roofs

Video: https://youtu.be/GWG29wowL68

Instructions from Video:

We will create a flat roof surface and the parapet wall. The automated roof routines allow for a sloped roof but if you are creating a built-up roof you use the Surfaces tool. This is an advanced lesson because we not only discuss inserting the flat roof but how to quantify the necessary materials too.

Select Insert>Surfaces>Surfaces

The Surfaces tool is a generic tool for the creation of horizontal surfaces. The default catalog will have a selection of floor, ceiling and roof surface options. Under the Roof Surfaces folder, select a surface and right-click and select Add Element.

First, give the new element the name of BUR Roof Surface. Beneath that categorize it as a roof type and gave it a thickness. None of the Details tab options are relevant, select the Appearance tab.

Give the Surface a material of gravel that is in the default catalog. This could be any image you want it to be.

Select the Line Work tab. It offers options for how the surface will appear in 2D. Give the surface a hatch pattern that appears like sand.

The last tab is the Quantity tab. Here add a group of assembled items to order every time the built-up roof is inserted. To add new assemblies, you click Add.

In the Assembly dialog box, it lists all the preassembled boxes of materials that we can add to our element. Right-click in the list and selected Add Assembly to create the BUR.

Give the assembly the name of BUR. Beneath that list all the parts to order each time this assembly is added to an element.  The assembled items are “parts”. Parts do not appear in 3D, they are just a name with a sku number, a unit of measurement and possibly a price. You can create parts to represent any product you need to order each time you create a flat roof. Each product has a corresponding formula to represent how much of the product to order according to its unit of measurement. In the video model sample, you can see that “Roofing Felt” is listed twice. One dry layer on the bottom and one mixed in with the hot asphalt. This could be a single entry since it is the same product. Left-click to select the formula and then click the button that appears.

Left-click in the formula window to edit the formula to  ((2 * Area )/ 400)*1.1.   2 layers of felt for the area of the roof divided by the coverage of one roll of felt and then multiplied again by 1.1 as a waste factor or overlap factor.  Click OK to update this one product.

Select the other roofing felt entry and click the delete key on your keyboard to remove it. Now let us look at adding a new product – curb product that will run the perimeter of the flat roof. Click Add.

In the Parts portion of the catalog, all parts are visible. If another part is required right-click and select Add Element.

Name the new part Roof Curb. You can see that a part only has a Quantity tab. A part is only used to quantify a nongraphical element that you need in your material list. The Phase and Usage are important to put this Roof Curb in the correct part of our material list. Give it a sku number of CURB. The unit of measurement is also important. Select LF for linear feet. Once that is all created, click OK. Click OK again and a new product is added to the list.

Now a formula is needed to specify how much Roof Curb is required. Click in the formula area and select the button that appears.

In the Formula dialog box, we know that the Roof Curb product is in linear feet. We need to know the length. Click the Length variable and it is added to the formula window. That is a simple formula. Ensure the Length parameter at the bottom of the dialog box is set to Feet and then click OK.

You can see the other formulas can be more complex depending on how you need to quantify an element, or it can be just simply Length. Click OK in the Edit Assembly dialog box and click OK again in the Assembly dialog box. We are now ready to draw the BUR Roof surface. Click OK to save all the changes.

Place the plan in a 2D view. Select Insert>Surfaces>Surfaces or select the Surfaces icon under the Building tab.  Select the BUR Roof Surface from the catalog. Move the cursor on the drawing screen area and left-click on every corner of the built-up roof. Once done, right-click and select Finish.

The Define Surface dialog box appears. Since a surface can be sloped we need to define the height of the surface where we started inserting it and then lock its value so it doesn’t change and then insert the height of the surface where we stopped inserting it. When they both are the same the slope will change to 0. Once complete click OK. The flat roof is in.

Now let’s work on the walls surrounding the built-up roof. Left-click to select one and then right-click and select Select all Similar to select all the exterior walls. Right-click again and select Properties.

The properties of the walls will appear. Select the Top and Bottom tab.  Here we specify the height of the wall. As a default, it is set to automatically extend up to the surface of the roof. We want it to extend past that to form the parapet. Select the Level option and change the wall height to 9’.  Click OK.

Now let’s look at everything we did in a 3D view. We can see the roof surface and the walls extending past. Now let’s review the material list. Select Tools>Analyze>Generate a Material list.

The list appears and scrolling down we can see the Roof items in our list.  I hope that makes you work easier!