> 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-top-chord-bearings.md). # Create Roof Trusses with Top Chord Bearings Before you begin, open Paragon Design. A top chord bearing truss bears above or below its bottom chord instead of on it. This article draws a vaulted 30' truss for a pole barn, then reworks each end for a different condition: on the left, the bearing drops 1' below the bottom of the truss (a leg down truss), and on the right, it sits 1' above the bottom of the truss on a bearing block. {% hint style="info" %} Note Distance fields accept values such as `30'`, `15'` or `14' 8-1/2"`. Slope fields take the rise per 12 of run, so enter `6` for a 6/12 slope and `-6` for a line that slopes down at 6/12. {% endhint %} ## Draw and Insert the Truss ### Step 1 - Click `Create` and choose `Component` You can also right-click empty space in the scene, or press `Ctrl + Q`, 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 `30'` in `Length` ### Step 3 - Under Left Heel, choose Heel Height for Heel Method and enter 3' in Heel Height The truss has a 3' heel at each end. If `Heel Method` already shows `Heel Height`, just enter the height. ### Step 4 - Under Right Heel, choose `Heel Height` for `Heel Method` and enter `3'` in `Heel Height` ![](https://2598702589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FzIkcl8vW0QKiqUIx7Xdc%2Fuploads%2FluvSlwL0LsQbZ8u7gBUr%2Ftcb-heel-settings.png?alt=media) ### Step 5 - Enter the pitch of the first top chord, such as `6` 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 6 - Click `Back Up` to remove the 8' line `Back Up` removes the last line you added. The slope stays at 6/12. If you pressed Tab in the previous step, there is no line yet and `Back Up` does nothing. ### Step 7 - Enter the run to the peak, such as `15'` in `Distance`, and press Enter Enter adds the first top chord: a 15' run at 6/12, from the top of the left heel up to the peak at mid-span. ### Step 8 - Enter the slope of the second top chord, such as `-6` in `Slope`, and press Enter `Distance` is still 15', so Enter adds the second top chord, 15' down at 6/12 to the top of the right heel. ### Step 9 - Enter the slope of the bottom chord, such as `5` in `Slope`, and press Enter Enter adds a bottom chord line at the current `Distance`, 15'. It needs to be shorter, so the next step removes it. ### Step 10 - 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 5/12. ### Step 11 - Enter the run of the bottom chord, such as `14' 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, a 14' 8-1/2" run ends directly under the peak, 15' from the left end. ![](https://2598702589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FzIkcl8vW0QKiqUIx7Xdc%2Fuploads%2FUhcOyptWRSfUzVLD7Fdt%2Ftcb-draw-profile.gif?alt=media) ### Step 12 - Click `Close Profile` The second bottom chord runs from the end of the first down to the right end, also at 5/12 and 14' 8-1/2" long, and the profile closes. The panel moves to `Shape Details`. ### Step 13 - Click `Next`, then click `Insert` This example keeps the default shape and structural details. ## Trim the Left Bottom Chord The left end becomes a leg down truss: the end vertical runs down past the bottom chord to a bearing 1' below the bottom of the truss. These steps are done in the scene. For more on trimming, see [Adjust Member Cuts to Improve Plating](/design/how-to/profile-truss/adjust-member-cuts-to-improve-plating.md). ### Step 1 - Select the left bottom chord, labeled `B1` under `Members`, or click to select it in the scene ### Step 2 - Hold Shift and click the right edge of the left end vertical The bottom chord is trimmed to the end vertical, so the end vertical can run past it. ## Add a Reference Line 1' Below the Truss ### Step 1 - Click `Create` and choose `Reference Line` You can also right-click empty space in the scene, or press `Ctrl + Q`, and choose `Reference Line`. There are a variety of Reference Lines you can draw, see [Create and Modify Reference Lines](/design/how-to/general/reference-lines.md). ### Step 2 - Click the line along the bottom of the truss, then click below it to place a parallel line ### Step 3 - Make sure the new line is 1' below the bottom of the truss If it isn't, select the new line and change its Offset to 1' in its properties. ## Move the Left Bearing to the New Line ### Step 1 - Select the left bearing, such as `Bearing A` under `Bearings`, or click it in the scene The `Bearing Properties` open in the right sidebar. `Bearing Reference Line` is in its `Geometry` section. ### Step 2 - Click `Geometry`, then under Bearing Reference Line, click `Select Existing` ![](https://2598702589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FzIkcl8vW0QKiqUIx7Xdc%2Fuploads%2FU9JpkvTy7ygcZq3QwTHx%2Ftcb-bearing-reference-line.png?alt=media) ### Step 3 - Click the new reference line in the scene, then press Escape The bearing moves down to the new line. ## Extend the Left End Vertical to the Bearing ### Step 1 - Select the left end vertical, EV1 in the video, under Members or in the scene ### Step 2 - Hold Shift and click the new reference line The end cut of the end vertical extends down to the new line, onto the top of the bearing. ## Change the Right End to a Bearing Block The right end bears 1' above the bottom of the truss. The end vertical becomes a bearing block, and a new end vertical takes its place inside it. These steps are done in the scene. Member names can change as you edit, so the names below are the ones in the video; check the labels on your truss as you go. To add members, see [Add and Modify Members](/design/how-to/general/members.md). ### Step 1 - Select the right end vertical, EV2 in the video ### Step 2 - In the member properties, choose Bearing Block for Member Type ### Step 3 - Add a new member along the left edge of the bearing block ### Step 4 - Select the new member and choose End Vertical for Member Type ### Step 5 - Select the right bottom chord, B2, then hold Shift and click the right edge of the new end vertical ### Step 6 - Select the web next to the new end vertical, W7 in the video, then hold Shift and click the left edge of the new end vertical ### Step 7 - Select the new end vertical, then hold Shift and click the top edge of the bottom chord The end vertical extends down to the bottom chord. ## Add a Reference line 1' Above the Bottom of the Truss ### Step 1 - Click `Create` and choose `Reference Line` ### Step 2 - Click the line along the bottom of the truss, then click above it to place a parallel line 1' up If the new line isn't exactly 1' up, select it and change its Offset in its properties. ## Trim the Bearing Block and Move the Right Bearing ### Step 1 - Select the bearing block, then hold Shift and click the new reference line The bearing block is trimmed back to the line, 1' above the bottom of the truss. ### Step 2 - Select the right bearing, such as `Bearing B` under `Bearings`, or click it in the scene ### Step 3 - Click `Geometry`, then under Bearing Reference Line, click `Select Existing` ### Step 4 - Click the new reference line in the scene, then press Escape The bearing moves up to the bottom of the bearing block. ## Analyze the Truss ### Step 1 - Click `Analyze` ### Step 2 - Click `Analysis and History` to see the results In the video, all checks pass. To view the results, see [Run & View Component Analysis](/design/how-to/general/run-and-view-component-analysis.md). ## Watch the video The video shows the same steps, except that each line is added with `Add Line` and both bottom chords are drawn by hand instead of with `Close Profile`. {% embed url="" %}
Video Transcript: Welcome! In this video, we’ll walk through creating a top chord bearing roof truss. For this scenario we are going to design a component for a 30 foot wide pole barn. The structure will contain some taller farm equipment so it needs to be vaulted. Let’s get started! Open the component creation subpanel and set the truss length to 30 feet. Next we will set both, left and right heel heights to be 3 feet. Our top chords will both have a 6/12 pitch. Remember to add a negative value for the right side. Both will be 15 feet long, so we will use the profile line tools to add both of these lines. Next we need to add the bottom chords. The bottom chords will have a 5/12 pitch. And the length will be 14 feet 8 and a half inches long for both. Add both bottom chords to close this profile. Accept the default settings and click insert. Let's look at two possible scenarios. For the left side, the bearing will be 1 foot below the bottom of the truss. Commonly referred to as a leg down truss. The other end will have the bearing 1 foot above the bottom of the truss. First we'll edit the left side. Let's trim the bottom chord to the right side of the end vertical. Next we will add a reference line 1 foot down from the bottom of the truss. Then we need to move the bearing to align with the reference line. To do this select the bearing, and in the properties panel under Bearing Reference Line click the Select Existing tool, then click on the new reference line. Press escape. Next, we simply need to update the end cut of the end vertical, so it extends to the new reference line. Select the end vertical, shift click on the reference line and that will extend the end cut to the top of the bearing. Move over to the right side and we will adjust this end. Let’s modify the end vertical member to now be a bearing block. Click the member and from the properties panel under member type select bearing block. Next we will add a new member. Place the new member to be on the left edge of the bearing block. Change this member to be an end vertical from the member type option. Now we need to trim up a few items. Let’s start by selecting the bottom chord, then shift click the right side edge of the end vertical. Next we will adjust the end of the W7 web to be cut to the left edge of the end vertical. Select W7, then shift click on the left edge of the end vertical. Now we need to extend the end vertical to the bottom chord. Click the end vertical and then shift click on the top edge of the bottom chord. We will adjust the bearing block end to be 1 foot up from the bottom of the truss. Insert a reference line 1 foot up from the bottom of the truss. Trim the bearing block back to the reference line. Click the bearing block and shift click the reference line. One last item, we need to relocate the bearing. Click the bearing, then in the properties panel under the bearing reference line tool click select existing, then click on the reference line. Now, we can analyze the truss to ensure all checks pass! That does it for this video on creating a top chord bearing roof truss with two different scenarios. We hope these two examples will help you when solving problems for your top chord bearing truss projects. We’ll see you in the next one!
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