Create Roof Trusses with Sloped Bottom Chords

Video Transcript:

Welcome! In this video, we’ll walk through creating trusses with sloped bottom chords. These components are commonly used on projects with vaulted ceilings or trays. Let’s get started!

Let's start by opening the component creation panel. Let’s select the scissor truss as a starting point. We will use 24 feet for the length. We’re going to change the top chord slope to 8/12. And we will set the bottom chord slope to 4/12. Press next and insert the component. Great, we will run a quick analysis, but it should pass. This is a simple example that you would commonly see in a vaulted room.

Now, let’s walk through a more complex situation that has a vault and an elevated bearing on one side. Click Create and select component. Here we will make sure the length is set to 24 feet.

Next enter 12 feet to create the line. And we will set the slope to be 8/12. Press Add line.

Then followed by a 12 foot line. With a negative 6/12 slope. Click to add this line.

For the bottom chord we want to insert an 11 foot, 8, and a half, inch line . Then set the slope to be 4/12. Click add line. Next we will click close profile.

We are going to set the right overhang distance to 0 in the shape details panel. Then click next. And insert, to wrap this part up.

Great.

Now that we have this truss inserted, we need to make some modifications to get our elevated bearing.

We need to remove the items that are labeled W3, W4, W5, W6, and EV2. Note these labels, as member labels will change as others are deleted. Remove the noted items from the component.

With those members now out of the way, we will add a horizontal member towards the right end of where T2, intersects the inside reference line, for the right side bearing. And then connect to B2.

Now we will insert a vertical member, at this new intersection up to T2. If needed fix the cuts so the splice is below this member.

Now we can add a member from W2. To where the inside edge of, W4 intersects with T2.

Next wrap up the webs, with a vertical at the center. After you start the member tool, double click on the reference line, to place it automatically.

Now, we need to update our right bearing.  This is an important step. If the member is not specified to be a bottom chord, bearing placement will not be possible. To do so convert W3 to a bottom chord. Select W3 and in the member properties info field for member type, set it to bottom chord.

Next we will clean up the truss. We will Trim the new bottom chord to the center of W4. By pressing shift while clicking.

Now select B2.   Look at the properties panel to see If a T2 Starboard cut is listed under B2 Right Cuts, if it exists, select it and delete this Right Cut.

We need to add a new, Right Cut, to the members properties window. Select the middle line from W4.

Next let's delete the existing bearing.

Here we will insert a new bearing at the right end of the updated bottom chord.

If the bearing jumps to the end, select the bearing, and from within the Bearing properties panel, click to check the bearing flipped box.

If needed, adjust the bearing to align with the right end of the bottom chord.  Next Click to analyze the truss.

Great...that all worked as it should.

All checks pass.

That wraps up this video on working with sloped bottom chords. See you in the next one!