To further clarify the framing details with regards to attic trusses and structural outlookers I've created a sample model with a proposed dropped top chord gable end attic truss:





Please download and review the model here:


https://3dwarehouse.sketchup.com/model.html?id=u8c3afc5c-482a-41ea-b223-988b1cccd8bc


I've also included the infill wall framing to help put everything into reference (light green).


Is this the appropriate way to frame an attic truss (gable end) with structural outlookers?

Just as a word of warning this plugin is far from a polished or finished product.  There are still a lot of loose ends that need tying up.  Case in point I have not yet enabled gable end trusses for the attic truss type.  The reason is the complication of dropping the top chord for structural outlookers where the attic truss has a spliced top chord.  Below is an example of a attic truss with a dropped top chord that I have encountered in the past but I don't know if this is the best method of handling this situation. 





I would like to enable structural outlookers for attic trusses in the next few days just to wrap this up.  Any thoughts or suggestions or examples of similar configurations are very much appreciated.

Version 1.4.7 - 03.28.2016
- Added Cathedral truss type, configurations: (4/X, 6/X).
- Metric input enabled for cathedral truss type.
- Added gable end trusses for cathedral truss type.



Note, that not all configurations have webs enabled however the top chords, bottom chords, gable end trusses and all advanced options are enabled.

A breakdown of the configurations for the Cathedral 4/X family:

I've been meaning to add in cathedral trusses for quite some time and I finally had the chance last night.  Configuration (3) shown below for a catheral 6/X truss:



Now I only need to code in the other six configurations and its ready to release as a new update.

Second look at cathedral trusses (6/X) family:



The logic required to triangulate these type of trusses becomes tedious.

Version 1.4.6 - 03.26.2016
- Added Cambered truss type, configurations: (6/X).
- Metric input enabled for cambered truss type.
- Added gable end trusses for cambered truss type.



Six variants of the (6/X) configuration dependent on the ratio of the camber width to span.  Notice that in all cases the top chord has six panels, the bottom chord varies from 4, 5 and 6 panels.

View model here:

https://3dwarehouse.sketchup.com/model.html?id=ued7e0d19-2843-4b3a-9786-3c15cf876fdf

Another look at the cambered truss:

I had someone ask me if it would be possible to create a small house or cabin based entirely on a raised heel attic truss profile, probably with some skylights for light.  I've never seen this type of design before but I don't see why it might not work.  Has anyone ever seen something like this done?  Basically an attic truss with a raised heel (48') resting directly on a stem wall foundation with post and beams or something similar.







The one issue I could see is if there were no windows for a bedroom (no egress) that was midway the length of the structure.  The design shown is 36' wide, 42' long with a 21' wide attic room.  6"x24" stemwall foundation, with a 12"x6" footing. 

Typically large attic trusses are quite expensive so it would seem that this would be an expensive way to build a house perhaps there is some other reason that makes this method of construction viable?

View model here:

https://3dwarehouse.sketchup.com/model.html?id=u88dea626-2d7e-45cb-8751-6f2f3b101fc5

Version 1.4.5 - 03.24.2016
- Structural outlookers (vert. & horz.) enabled under advanced roof options for Scissor (4/4) truss type.

I guess I somehow missed enabling structural outlookers for scissor trusses.  Anyhow this issue was brought to my attention this evening so I've tried to rectify it as much as possible.  After delving into the code I realized that the scissor truss module needs a major rewrite and cleanup so I was only able to get structural outlookers enabled for the 4/4 configuration.  Later next week I will jump back into this module and work on the 2/2 and 6/6 configuration.

Same truss as above but in SketchUp:



View model here:

https://3dwarehouse.sketchup.com/model.html?id=u93559996-8808-4186-9f65-3065a9d3f64f

A 9:12 barrel vault truss with a 16' wide barrel:

Using a typical Barrel Vault 8/7+4 or 8/7+2 configuration I come up with the following triangulations.  I'm sure there are other methods of configuring these webs but for the purposes of the plugin I think these solutions will suffice for now:



High Resolution PDF copy here:

http://design.medeek.com/resources/truss/BARREL_VAULT/BARRELVAULT_STUDY1_REVA2.pdf

Based on this matrix I've been able to come up with a simple algorithm for the triangulation of this truss type.  I'll admit the barrel vault truss is one handsome devil.

After adding Bowstring and Bow Barrel trusses the only common other round truss type is the Barrel Vault.  The problem with this type of truss is the webs get messy or at least hard to predicate because of the interplay between the vault and the pitched roof above it.  In an effort to better understand this type of roof/ceiling configuration I've created the matrix below:





High Res. PDF copy here:


http://design.medeek.com/resources/truss/BARREL_VAULT/BARRELVAULT_STUDY1.pdf


I am trying to predict the max. height of the vault given a specific roof pitch and and vault width to span ratio.  Perhaps I am recreating the wheel and some architect or designer has devised a method to create the perfect barrel vault given a roof pitch and other criteria.


I would be interested in what other opinions are on this matter.

Version 1.4.4 - 03.21.2016
- Added Polynesian truss type, configurations: (4/4).
- Metric input enabled for polynesian truss type.
- Added gable end trusses for polynesian truss type.



I'm not sure where this type of truss is commonly used but whenever I see one I think of a bus stop or train station:



Advanced options are not yet enabled for this truss type yet, so sheathing, fascia, rake will have to come later.