> For the complete documentation index, see [llms.txt](https://docs.paragontruss.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.paragontruss.com/design/how-to/profile-truss/create-roof-trusses-with-sloped-bottom-chords.md). # Create Roof Trusses with Sloped Bottom Chords Before you begin, open Paragon Design. Trusses with sloped bottom chords are common over vaulted ceilings and trays. For a simple vault, start from the `Scissors` shape and give the bottom chord a lower slope than the top chord. For a vault with an elevated bearing on one side, draw the profile yourself and then rework the webs at the elevated end. {% hint style="info" %} Note Distance fields accept values such as `24'`, `12'` or `11' 8-1/2"`. Slope fields take the rise per 12 of run, so enter `8` for an 8/12 slope and `-6` for a line that slopes down at 6/12. {% endhint %} ## Create a scissor truss for a vaulted ceiling ### Step 1 - Click `Create` and choose `Component` You can also right-click empty space in the scene, or press `Ctrl + Q`, and choose `Component`. ### Step 2 - Choose the `Scissors` shape The `Component Insertion` panel moves to `Shape Details`. ### Step 3 - Enter the span, such as `24'` in `Length` ### Step 4 - Set the slopes, such as `8` in `Top Chord Slope` and `4` in `Bottom Chord Slope` The bottom chord slope must be lower than the top chord slope. An 8/12 roof over a 4/12 ceiling is a typical vault. ![](https://2598702589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FzIkcl8vW0QKiqUIx7Xdc%2Fuploads%2FnJNmVx6cdXxaefBD6Joj%2Fsloped-bc-scissors-shape-details.png?alt=media) ### Step 5 - Click `Next`, then click `Insert` ### Step 6 - Click `Analyze` A simple vault like this one should pass every check. To view the results, see [Run & View Component Analysis](/design/how-to/general/run-and-view-component-analysis.md). ## Draw a Vaulted truss with an Elevated bearing This truss has a vault and an elevated bearing on the right side. You'll draw its profile line by line. ### Step 1 - Click `Create` and choose `Component` The `Component Insertion` panel opens at `Basic Shape`. ### Step 2 - Under Draw a freeform profile from scratch, enter the span, such as `24'` in `Length` ### Step 3 - Enter the slope of the first top chord, such as `8` in `Slope` Under Profile Line, `Distance` is how far a line runs horizontally, and `Slope` is its pitch. Pressing Enter in either field adds a line straight away, the same as clicking `Add Line`, using the current values of both fields. Here, Enter adds a line at the default `Distance` of 8', which the next step removes. To set the slope without adding a line, press Tab instead of Enter. ### Step 4 - Click `Back Up` to remove the 8' line `Back Up` removes the last line you added. The slope stays at 8/12. If you pressed Tab in the previous step, there is no line yet and `Back Up` does nothing. ### Step 5 - Enter the run to the peak, such as `12'` in `Distance`, and press Enter Enter adds the first top chord: a 12' run at 8/12, from the left heel up to the peak. ### Step 6 - Enter the slope of the second top chord, such as `-6` in `Slope`, and press Enter `Distance` is still 12', so Enter adds the second top chord, 12' down at 6/12 to the right end of the truss. The right heel is added automatically, about 2' taller than the left heel. ### Step 7 - Enter the slope of the bottom chord, such as `4` in `Slope`, and press Enter Enter adds a bottom chord line at the current `Distance`, 12'. It needs to be shorter, so the next step removes it. ### Step 8 - Click `Back Up` to remove the bottom chord line `Back Up` removes only the bottom chord line. The top chords stay, and the slope stays at 4/12. ### Step 9 - Enter the run of the bottom chord, such as `11' 8-1/2"` in `Distance`, and press Enter The bottom chord starts after the seat cut at the left bearing. With a 3-1/2" seat cut, the default for a 2x4 bearing, an 11' 8-1/2" run ends directly under the peak, 12' from the left end. ![](https://2598702589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FzIkcl8vW0QKiqUIx7Xdc%2Fuploads%2F6cgl4vYypA6cLBgYCAqc%2Fsloped-bc-draw-profile.gif?alt=media) ### Step 10 - Click `Close Profile` The second bottom chord runs from the end of the first down to the right end, and the profile closes. The panel moves to `Shape Details`. ### Step 11 - Under Right Overhang, enter `0` in `Overhang Distance` The elevated bearing has no overhang at the right end. ![](https://2598702589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FzIkcl8vW0QKiqUIx7Xdc%2Fuploads%2FCjtTFxZ3R84wvgEq7AI8%2Fsloped-bc-shape-details.png?alt=media) ### Step 12 - Click `Next`, then click `Insert` ## Rework the webs for the elevated bearing These steps are done in the scene. Member names change as you delete and add members, so the names below are the ones in the video; check the labels on your truss as you go. To add members and bearings, see [Members](/design/how-to/general/members.md) and [Bearings](/design/how-to/general/bearings.md). ### Step 1 - Delete the webs and end vertical at the right end In the video, these are W3, W4, W5, W6 and EV2. Select each one and press Delete. ### Step 2 - Add a horizontal member for the right bearing and connect it to the second bottom chord Start the member where the second top chord (T2) meets the inside reference line at the right end, and run it to the second bottom chord (B2). ### Step 3 - Add a vertical member from the new intersection up to the second top chord If needed, fix the cuts so the splice sits below this member. ### Step 4 - Add a web from W2 to where the inside edge of the new vertical meets the top chord ### Step 5 - Add a vertical web at the center After you start the member tool, double-click the reference line to place the vertical automatically. ### Step 6 - Make the new horizontal member a bottom chord This is important: a bearing can only be placed on a bottom chord. Select the horizontal member (W3 in the video) and, under Info in the member properties, choose Bottom Chord for Member Type. ### Step 7 - Hold Shift and click the center of the new vertical to trim the new bottom chord to it ### Step 8 - Replace the right cut of the second bottom chord Select B2. In its member properties, under Right Cuts, delete the cut against T2 if there is one. Then add a new right cut and pick the middle line of the new vertical. ### Step 9 - Delete the existing right bearing and insert a new one at the right end of the new bottom chord If the bearing jumps to the wrong end, select it and check Bearing Flipped in the bearing properties. Adjust the bearing so it lines up with the right end of the bottom chord. ## Analyze the truss ### Step 1 - Click `Analyze` In the video, all checks pass. ## Watch the video The video shows the same steps. In the video, each line is added with `Add Line` after both values are entered. {% embed url="" %}
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!
--- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.paragontruss.com/design/how-to/profile-truss/create-roof-trusses-with-sloped-bottom-chords.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.