Development and Updates for the Medeek Truss Plugin

[Medeek]

With non-structural lookouts would you frame them something like this?  This question is mostly directed at the contractors and carpenters out in the field who actually have to build these roofs.  Typically as an engineer I never worry about these details especially when they are non-structural.



In my opinion they aren't really doing a whole lot, much better to drop the gable truss and then cantilever them from the first in board truss (ie. structural outlookers).

[Medeek]

Hip Truss Algorithm:

[Medeek]

Outlookers oriented horizontally with gable end truss top chord dropped:



View model here:

https://3dwarehouse.sketchup.com/model.html?id=9f3dd430-1b90-435a-bfa6-f2bbe4d3e553

[Medeek]

Version 1.6.3 - 06.19.2016
- Added Gable Dormers to the Minor Roof Sub-Menu (dormer walls only).

For now only the walls of the dormer are created:



View model here:

https://3dwarehouse.sketchup.com/model.html?id=e17866e5-2e1d-4fb7-8203-fcb6484e8f08

I am still ironing out the details on how to best model the roof geometry.  I will probably offer either a rafter or truss option.  Other details such as multiple windows will also come later.

For now please test the metric and imperial wall creation.  I will probably need to post a tutorial video on how to use this feature since it involves selecting the main roof plane (top of a rafter or truss) and then two points that define the width/exterior corners of the dormer.

[Medeek]

Testing the dormer (wall) feature out with a gambrel attic truss:



These dormers have a typical gable profile but it might be useful to have a gambrel dormer option as well to match with a gambrel style roof.  Note that I have not shown all of the ladder framing in the model.  On a roof like this it could get quite extensive.

To generate the dormer roof I just used my rafter roof feature and then trimmed the elements back manually. 

View model here:

https://3dwarehouse.sketchup.com/model.html?id=315004e6-6c2e-427e-981e-dc891371c77c

https://www.kubity.com/p/uCN2F6

[Medeek]

Same barn with a few more details.  For gambrel attic advanced options I should also include the option for a crow's beak as shown in this model and the option to set the extension.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=1d1a6c57-08c4-46a4-a93e-9ae28b9f477e

https://www.kubity.com/p/uraGAJ

[Medeek]

Under advanced options for gable roofs (truss and rafter) I am thinking about adding a "roof return" option.  Any thoughts on "greek returns":





The images above shows a roof return with a gable termination, alternatively this could end with a hip termination as in below:



Or with a full greek which stretches across the entire span:



Does anyone have any specific framing details on how best to frame these roof elements?

As far as the logic to add them into the plugin it won't be a big deal, just an additional module that plugs into the advanced roof module.

To simplify things I would used the same pitch on the returns as on the main roof.  The three variables would be:

1.)  Return Type: Gable, Hip, Full
2.)  Length of the Return
3.)  Extension beyond Rake

[Medeek]

A quick study of a hip return:



Notice the inboard hip rafter does not terminate at the gable wall when the return length is too short.  This poses some interesting framing given this situation, note the return on the right side of the roof is this case, not entirely sure how one would support/terminate the hip rafter in this situation.

When the return length allows the hip rafter to terminate at the gable wall then the framing is fairly straightforward.

The hip rafter will terminate at the gable wall when the return length is greater than or equal to twice the total return extension (Rakeboard Width + Gable Overhang + Return Extension).

The other question that I have is how to apply the sheathing to these small odd shaped roof segments.  How far up under the overhang should the sheathing extend?

View model here:

https://3dwarehouse.sketchup.com/model.html?id=482d84f7-52a6-4b56-bf7d-4f373d825ec0

https://www.kubity.com/p/ytJPd4

[Medeek]

This is an excellent link:

http://spot.pcc.edu/~rsteele/BCT122_123/return_eave.pdf

They run the outside hip rafter back to the gable wall and don't run the barge rafter (rake board) to the fascia like I've shown, maybe I've got this wrong...

This method would allow for sheathing of the return without having to notch around the barge rafter.  I call this the floating barge rafter method:



Compare with extending the barge rafter all the way to the fascia board:

[Medeek]

Version 1.6.4 - 06.27.2016
- Added roof return option within the advanced options menu for common, scissor and vaulted trusses, configurations: (HIP).



View model here:

https://3dwarehouse.sketchup.com/model.html?id=790b256d-72fe-46c9-b49c-dd7da0209a02

This option is available for most typical triangular shaped trusses.

I will be adding the gable and full return at a later date, currently only the hip return is available.  Another limitation is that the return roof pitches currently default to the main roof pitch.  I need to add some additional code that will allow the pitch of the return portions to be set independent of the main roof pitch.

[Medeek]

12:12 main roof with a 8:12 hip roof return.  The interesting part is the hip rafter
where the return meets the main roof plane.  The dropped hip rafter is off center so that it supports the sheathing from both planes.  The calculations might prove challenging.

[Medeek]

Version 1.6.5 - 07.07.2016
- Added energy/raised heels for polynesian truss type (1 variant: vertical w/ strut).
- Fixed HTML truss selector menu so that window size no longer truncates truss images.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=c4ecc314-9702-4c99-9148-ca0790178583

[Medeek]

This is an example of a 24' x 24' garage that I would like to build on my property this summer or the next. 



View model here:

https://3dwarehouse.sketchup.com/model.html?id=77329ddc-a170-4dde-945e-4e413304f620

I created the foundation and roof with minimal effort using my own plugins.  The walls were created initially with the housebuilder plugin however I then manually edited the walls.  Note that the top plates overlap properly as they should.

Also note that the garage door wall is a double portal frame.  I would like for my wall plugin to automatically create this standard type of portal frame (PFH) both single and double (ie. Garage Door Option). Notice the embedded Simpson Strong-Tie STHD14 holdowns.

I like to use 2x jamb boards around the door perimeters when the stem wall projects above the concrete slab, this may be atypical constructon for others.  Local contractors like to embed a pressure treated nailer into the concrete.

In theory I should be able to create this exact model using the Foundation, Wall and Truss Plugin and do it all within 5 minutes or less.  That is the goal.

With the wall plugin I will have the standard linear wall tool but I would also like to have a rectangle wall tool that will immediately throw up 4 walls given three user selected points, similar to the truss and roof plugins.

[Medeek]

This is a quick study of a post frame roof using doubled trusses with 2x6 purlins @ 24" o/c.  This is pretty typical for a  pole barn or post frame building constructed locally:



View model here:

https://3dwarehouse.sketchup.com/model.html?id=0240f563-8350-460d-b07c-9f7dae117782

Notice how the rake and fascia boards are raised above the trusses so that they are flush with the roof plane and purlins.  The overhang can be achieved a number of ways but one method is to extend rafters from an inboard purlin and also attach to the post as shown. 



There are a number of other ways to frame the overhang, a quick search online will attest to this.  Sometimes a header is used between posts which allows for a truss spacing which is closer than the post spacing.

Purlins position right at the peak seems fairly standard, based on some plansets that I have.

When you add end walls with posts you can usually eliminate the doubled truss at the gable ends and you often will see a gable end truss that has girts (horiz. members) instead of studs.



With a purlin roof I almost need to create a separate menu item and module to properly deal with it.

Here is an interesting double truss design but with scissor trusses:

[Medeek]

Version 1.6.6 - 07.15.2016
- Added roof battens option within the advanced options menu for common, scissor and vaulted trusses.
- Battens can be offset from the fascia board.
- Battens at peak option enabled.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=e7f7a812-53da-4c57-b40a-b28bbacf96e2

Currently this feature is only available for truss roofs, I still need to add it to hip and gable rafter roofs.

If sheathing is enabled with battens, the battens are placed on top of the sheathing.