In this session, I am going to show you how to use the “Stair” tool to create stairs. Stairs element usually consists of runs, landings, supports, and railings. Before we start to sketch stairs, two important dimensions should be carefully calculated. One is the riser height, and the other is the tread depth. Revit uses two type parameters to control these dimensions; they are the “Maximum Riser Height” and the “Minimum Tread Depth,” respectively. In the following, I will introduce you how to accurately set the parameters of a stair type in Revit and what to pay attention to when we are creating stairs. Go to the “Architecture” tab, and on the “Circulation” panel, select the “Stair” tool. In the drop-down menu, select the “Stair by Component” tool. On the “Properties” palette, click on the “Edit Type” button, then duplicate a stair type. We should set the parameters of a stair type according to the requirements of the project. Let me explain these type parameters and the settings of them one by one. A stair riser is a near-vertical portion of a stair element, and a stair tread is the horizontal portion of a stair element. People walk on stair treads to go up and down the stairs. The “Maximum Riser Height” parameter specifies the maximum height of each riser on the stair element, and the “Minimum Tread Depth” parameter sets the minimum tread width along the center path for all common runs. Here comes a question. Why does Revit use “Maximum Riser Height” rather than just “Riser Height?” Let me use an example to explain it. Assume the level height is 240 cm, and we specify the riser height as 25 cm. Therefore, the number of stair steps will be 240 divided by 25, which is 9.6. That means the last riser of this stair will be only 15 cm high. This results in non-uniform riser height. To avoid this problem, Revit divides the level height by another parameter called Maximum Riser Height. Let us see how it works. Now we specify the Maximum Riser Height as 25 cm, and Revit automatically calculate the minimum number of stair steps,which is again 9.6. To make the riser height uniform in the set of stairs, Revit automatically choose 10 as the actual number of stair steps. After deciding the number of steps, Revit automatically calculates the riser height to be 240 divided by 10, which is 24 cm. Let us go back to Revit to create stairs, we set the “Maximum Riser Height” as 19 cm and the “Minimum Tread Depth” as 23 cm. After Revit’s automatic calculation, the “Actual Riser Height” is 18.44 cm and the “Actual Tread Depth” is 24 cm. Next, let us set the run type. Click on the rightmost button in the “Run Type” field. Then we can specify the materials and sizes of the risers and the treads. These parameters are used to determine the finishes on stairs, including their thickness and material types. After we specify the parameters, Revit will automatically deduct the thickness of finishes from the height of concrete of a riser, so that the riser height will be maintained as calculated. Nosing length controls the amount of tread depth that overhangs the next tread, mainly for the finishes on treads. In most cases, stairs have nosing length up to one or two centimeters long. Here we can set the nosing length and nosing profile. Next, let us look at the “Risers” field, where we can set the parameters of the risers. Note that here is a “Slanted” option. Risers are not required to be perpendicular to treads, and a slanted riser can make people climb the stairs more easily. Check the “Slanted” option if we want to make the risers slanted. Under the “Construction” field, let us see the settings of “Landing Type.” Click on this small button to adjust the “Monolithic Thickness” and the “Monolithic Material.” Once we have specified the parameters, click on “OK” to exit “Type Properties” window. Then we need to set the constraints. In the “Properties” palette, we can set the “Base Level,” “Base Offset,” “Top Level” and “Top Offset.” On the “Options Bar,” enter the “Actual Run Width,” and then go to the “Properties” palette to set the “Actual Tread Depth” as 24 cm. Now, we are ready to start creating stairs in the drawing area. Click to enter the run start point on the underlay and then move the cursor toward the direction of stair climbing. We can see the text below the light gray profile of the stair. This text shows the number of risers created and remaining. According to the underlay, there is no landing for this stair, so here we click on the run end point to finish creating this stair. Under the “Modify/Create Stairs” tab, on the “Component” panel, we click on the green check icon to complete creating the stair. Let us switch to the 3D view to see the stairs. In addition to the stairs, the railings of the stairs are also automatically established. This concludes the demonstration on how to create stairs in Revit.
