Truss Design

[Medeek]

Version 1.9.0 - 05.27.2017
- Added flat truss type, configurations: flat, monopitch, pitched.
- Metric input enabled for flat truss types.
- Added gable end trusses for flat truss types.
- Enabled the following end details for all flat truss types: None, Overhang, Cantilever, Mansard, Parapet, Mansard w/ Parapet.

Plates and advanced options are still in progress. With the amount of configurations available with this truss type it will probably be a while before these next elements are in place.

The flat truss type is very configurable and with a little adjustment of parameters you can also easily create a (non-attic) gambrel truss using the flat pitched option.

 

[Medeek]

The top chord bearing option is almost complete for the flat trusses. Here is a preview with a Mansard /w Parapet on the left side and a cantilever on the right side. The bearing widths can be set independently as can the parapets heights now.

I'm not entirely satisfied with the UI for this truss type, a proper html UI would be much more intuitive but time consuming to create. Yet another important item on the todo list.

The plugin is starting to stray into some fairly exotic truss territory.

 

[Medeek]

Version 1.9.1 - 06.09.2017
- Added plywood gusset plates for common fink trusses.
- Enabled a "WOOD" plate type option in the global settings.

*Note that the wood gussets are currently only available for the Fink truss, if anyone needs them enabled for a different truss please let me know.

 

[Medeek]

Raised Heel WGC Truss

Added plywood gusset plates for raised heel common fink trusses.

View model here:

https://3dwarehouse.sketchup.com/model/b21431bc-c3b6-4038-a81e-f27fc78f69b1/WGC-Truss

 

[1saxman]

'As an Architectural designer I never needed OR wanted to do all the work necessary to design a truss. And we always used trusses, partly because designing joist and rafter and the connections was a pain. And the truss mfg., and their engineers take all the liability.'

Same here. As a Civil Engineering technologist for 40 years I 'designed' a number of small buildings and always did the same thing; let the contractor provide the engineered truss design with an engineer's stamp. To me the purpose of the truss roof was to eliminate spreading force by transferring that tension to the horizontal element. Consequently I used it in certain applications where attic space was not a consideration. Its not a good solution for most residential uses.

 

[Medeek]

Advanced options are now configured: fascia, sheathing, cladding, gypsum, ceiling battens.

Girder trusses can be single or double ply, I can add more plies if requested.

I've also added the option to use a drop-in purlin frame, see image and model below:

View model here:

https://3dwarehouse.sketchup.com/model/f313c80f-fbe0-4a45-a086-6914319f3b26/Medeek-Office-Hip-Roof

Items still needing attention:

- Error check in metric mode.
- Internal webs for hip trusses
- Internal web algorithm for end and hip jack trusses.
- Raised heels
- Enable soffit cut for jack trusses and hip trusses.
- Enable plates for hip, jack and drop-in purlin.
- Setup the half-a-hip option (one end is a gable end).

 

[Medeek]

Using the stepdown truss set as a primitive it is possible to generate some fairly complex roofs:

In this case I created two hip sets and then tied them together with a valley set. View model here:

https://3dwarehouse.sketchup.com/model/1cd3ccf1-e7f8-492c-b4d0-f12286a6ba8e/Hip-Roof-9

This one way to do it but the more typical way would be to further customize the larger hip set so as to eliminate the valley set entirely.

Interesting how the larger girder truss ties into the smaller girder truss (3 ply). The smaller girder truss would need to be beefed up to handle this point load if there is no bearing wall below, and then the point loads from the posts supporting the girder truss (in wall) would probably need spread footings.

A few seconds to create the basic geometry and then about 10 minutes of trimming (with the trim function) and manual adjustments. I can see that the truncated hip set feature would be nice to have where hip roofs are tying into other roofs, similar to what I have enabled for the gable truss tool.

 

[Medeek]

It was pointed out that stick framing the valley set is often preferred in some locales (ie. California). This is an example of a "California Fill".

I've seen them done this way up here in Washington but probably not as often.

I haven't shown the vertical studs and their pads only the sleepers, rafters and ridgeboard are shown, view model here:

https://3dwarehouse.sketchup.com/model/fa645631-ede6-41c9-bbf4-74092fd8ea7a/Hip-Roof-10

Where the Fill connects back to the other roof do I have that correct? Do you install another rafter against the truss?

Notice that I did not bevel the 2x12 sleeper, just shifted it so that if lines up correctly with the roof plane, of course if this is mounted on top of the sheathing then the position will change accordingly.

Those double bevel cuts on the rafters would scare me, but then again I'm no carpenter.

Funny how everything has a "California" in front of it:

- California Corner (Ext. Wall Corner) http://design.medeek.com/resources/framing/FRAMING_CORNERS.pdf
- California Fill
- California Hip Set https://3dwarehouse.sketchup.com/model/97644895-c988-435c-bdc4-c7b8956a6d46/California-Hip-Set-Rev-2

I guess the Californians are innovators.

 

[Medeek]

Added energy/raised heels for stepdown hip set (3 variants: wedge, slider and vertical w/ strut).

View model here:

https://3dwarehouse.sketchup.com/mo...3ceee60652b/Commercial-Building-with-Hip-Roof

Now the possibilities are limitless since you can match the heel height of any other roof (ie. rafter, TJI etc...)

Adding in this feature was not as bad I thought it would be but each truss type in the set must be considered and dealt with separately:

- Common Trusses
- Hip Trusses
- End Jacks
- Hip Jacks
- Corner Jacks

 

[Medeek]

For those not familiar with truss hip sets, here is a primer:

6" raised heel with open end jacks and a drop-in purlin frame.

 

[Medeek]

Version 1.9.3 - 06.25.2017
- Added Terminal hip set trusses.
- Enabled advanced options for terminal hip sets.
- Added energy/raised heels for terminal hip set (3 variants: wedge, slider and vertical w/ strut).
- Added the option for open vs. closed end jack and single and double ply girders

View model here:

https://3dwarehouse.sketchup.com/model/40ac6469-0d4b-4462-914e-7f6f7ae0602f/Standard-Terminal-Hipset

This style of hip set is typically used for spans less than 20 ft.

 

[Medeek]

I think my love of trusses sometimes blinds me to the fact that most people don't really care to model the details of their roof. With that being said I don't think my time was wasted since I have learned an immense amount about programming a SketchUp Plugin and manipulating the API. However, I think it is now time to give the Truss Plugin a rest and focus my efforts on projects that will give me a better return for my investment. I'm not sure what exactly those projects are yet but I'm working on it.

 

[Medeek]

Here we go again:

https://www.kickstarter.com/projects/128644708/medeek-construction-plugin-library

 

[Medeek]

I've been looking at some floor truss layouts and it appears that within a given truss set or assembly the chase will line up across multiple spans as I have shown here:

View model here:

https://3dwarehouse.sketchup.com/model/25d2af3a-a5e6-498f-b2eb-8f4b773927ca/Floor-Truss-Study-3

Generating a new truss component for each separate span is not too difficult, similar to generating a new step down hip truss component every 24". One thing to note is that a polygon outline will only work for floor trusses if the angles are all orthogonal, at least the bearing walls where the trusses terminate.

I'm a little unclear how to deal with the ladder trusses at the transition between different spans, perhaps someone has a 3D model or pictures giving me some clarity in these areas.

It took me about 15 minutes to create this complex floor truss set using the rectangular floor truss tool (3 separate truss sets) and the trim tool, not terrible but it would be so much better if I could achieve the same result in a matter of seconds with no manual editing.

Cutting holes in the floor and having the hole cutting tool able to regen the proper trusses is also a hot item related to this discussion. That would make the floor truss feature actually functional as a real world design tool.

Another issue is multiple chases within a truss set. One central chase seems the most typical but two chases positioned within the central third of the truss span also appears to be quite common. So far I have not seen more than two chases in a given floor truss span, probably for good reason. The ability to create two chases rather than just one is now on the "todo" list.

 

[Medeek]

Tutorial 5: Hip Truss Sets (24:32 min.)

 

[Medeek]

If I ever do build my office I was thinking of doing some sort of cedar siding and then putting my logo or some of my other designs on the exterior:

View model here:

https://3dwarehouse.sketchup.com/model/1bc480bd-0bc9-4f5a-b6fe-441d73c84183/Medeek-Office-with-Logo

Some of my other designs are here:

http://www.wilkersonart.com

 

[American Locomotive]

Great work, keep it up

 

[mike93lx]

wow, very impressive

 

[mike93lx]

I've got to fix my wife's computer today so that will probably stop me from getting any real meaningful work done on the plugins but at least I've been able to throw together a first draft for the office I want to build. Any thoughts on improving the design, sometimes once you get an idea in your head it is hard to see outside the box.

I haven't shown the doors or the front porch which will probably be quite small and pressure treated lumber.

- 32'x24'
- 5:12 or 6:12 roof with asphalt shingles
- two rooms
- 9' ceilings
- stemwall foundation with crawlspace
- carpet throughout
- 5/8" wallboard
- 3068 doors, (1) 4040XO, (3) 5040XO
- 11-7/8" I-Joists at 16" o/c
- studs DF No. 2, 2x6 @ 16" o/c
- sheathing will probably be 1/2" plywood, I don't like OSB in our climate.
- Siding Hardiplank or cedar siding, my budget may call for T11 though.
- Electric wall cadet heaters
- 50 AMP sub-panel from house
- 16" overhangs at eaves and gables with gutters and downspouts and 4" drain lines away from building.

no bathroom? I think I'd want more windows too.

 

[Medeek]

Version 1.9.4 - 07.08.2017
- Added energy/raised heels for triple howe truss (3 variant: wedge, slider and vertical w/ strut).
- Metal plate connectors now enabled for triple howe trusses.

Below would be a typical example of a 60' span using a triple howe truss.

However, in most cases where the design calls for taller walls one would probably go with a steel building or CMU block walls. This was the case on a building I designed about 10 years ago (Wasatch Building Supply, Utah) that had 20 ft. walls. Its too bad I don't have an interior photo showing the trusses inside the warehouse roof, its quite a sight to behold.

 

[notlob]

Are you a licensed architect? If not, it is illegal in most states, including Washington, to represent in any fashion that you are an architect.

Just by making this truss design software available, you are setting yourself up for enormous liability if someone uses it to design a structure and it fails and injures or kills someone. That liability increases exponentially if you represent yourself as an architect and you don't possess the requisite license. I hope you have good insurance, and lots of it.

Washington state statute:

18.08.310 Authorization to practice required

(1) It is unlawful for any person to
practice or offer to practice architecture in this state, or to use
in connection with his or her name or otherwise assume, use,
or advertise any title or description including the word "architect,"
"architecture," "architectural," or language tending to
imply that he or she is an architect, unless the person is registered
or authorized to practice in the state of Washington
under this chapter.

 

[Medeek]

Version 1.9.5 - 07.11.2017
- Added energy/raised heels for quad fink truss (3 variant: wedge, slider and vertical w/ strut).
- Metal plate connectors now enabled for quad fink trusses.

This concludes the updates needed for common trusses. I still have a number of updates for all the other truss types to bring them up to speed.

 

[Medeek]

Are you a licensed architect? If not, it is illegal in most states, including Washington, to represent in any fashion that you are an architect.

Just by making this truss design software available, you are setting yourself up for enormous liability if someone uses it to design a structure and it fails and injures or kills someone. That liability increases exponentially if you represent yourself as an architect and you don't possess the requisite license. I hope you have good insurance, and lots of it.

Washington state statute:

18.08.310 Authorization to practice required

(1) It is unlawful for any person to
practice or offer to practice architecture in this state, or to use
in connection with his or her name or otherwise assume, use,
or advertise any title or description including the word "architect,"
"architecture," "architectural," or language tending to
imply that he or she is an architect, unless the person is registered
or authorized to practice in the state of Washington
under this chapter.

There is a certain amount of liability with anything you do. If I made guns and someone accidentally shot them self with it would I be liable? If I made a beam calculator and someone used it but the beam failed would I be liable? It doesn't matter what you do, there is always some risk associated with it.

The bottom line is people want the information, how and what they decide to do with it is entirely up to them. Whenever you are designing a structure that possibly requires engineering I strongly recommend contacting a local engineer and getting an educated opinion. You don't know what you don't know. Calculating and engineering trusses is a complex proposition, the truss designer attempts to expose all of the details of member and plate design.

A number of structural engineers and architects actively use this software, both the plugin and the truss designer. Both products are still a diamond in the rough but have already found some utility in the real world.

 

[Medeek]

The truss designer is a tool just like any other, used incorrectly it can cause harm. One can just as easily download a trial copy of RISA2D and attempt to design a common fink truss with it, given the same loads and geometry you will get the same axial, shear and moment loads as my truss designer. This is how I actually checked to see that my matrix analysis algorithms were working correctly, comparing with the same model in RISA2D. How is my software any different from any of these other structural softwares? It isn't, again there is liability with any product you put out in the general domain.

 

[Medeek]

Fixed a minor bug with the tail bearing truss module. The user should now be able to input a roof pitch up to 16:12. This was such a minor fix that I'm not rolling a major revision, just a sub-revision: 1.9.5b.

 

[Medeek]

Tonight I was thinking it might be kind of cool to enable an option for hip and ridge (cap) on hip roofs.

After about an hour of coding I generated this:

I've got the hip cap figured out at the eaves but I'm a little unsure how to terminate everything where the hips meet the ridge:

View model here:

https://3dwarehouse.sketchup.com/model/cf1c9a13-1b28-4a79-84cc-363b505ec34b/Hip-and-Ridge-Study

 

[Medeek]

Added a hip & ridge option for all gable truss roofs (sub. rev. 1.9.6b):

View model here:

https://3dwarehouse.sketchup.com/model/1c99964a-c4d5-482f-a58b-75e828ec5dd6/Ridge-Cap

 

[Medeek]

This afternoon I began to put together the HTML for the timber truss GUI (what I have so far):

I think I've reduced a metal plated (bolts) timber truss down to twenty (20) parameters.

Hopefully the preview panel will help simplify the entry of these parameters and give the user instant feedback on what each one does. With these sort of trusses the look and feel of the truss is every bit as important as the structural aspect so a preview is very important.

The preview panel will not only show the timbers but also the metal plates and exact position of each bolt.

Once the user submits "go", the timber truss module will draw one (1) timber truss with all of the timbers, metal plates, bolts, nuts and washers.

In the global options the user will be able to specify the bolt standard and the washer standard as well as set the material (color) for the plate and hardware.

As usual the design and programming is a little more involved than I originally anticipated but in the end it should be quite dramatic to be able to create a fully bolted and plated timber truss.

I'm probably going to need a full week to complete this, so given my current schedule and hours it will probably be 2-3 weeks before this is ready to release.

 

[Medeek]

Progress is slow but steady:

Now I just need to add the bolts to the peak and heal plates...

 

[manwithtools]

You have certainly put a lot of work into this. Great job, thanks for sharing.

 

[Medeek]

I've got all of the bolts working now for each plate as well as the extra logic to make sure bolts don't get too close to the scarf line at the heel joint.

http://design.medeek.com/resources/timbertruss/web_dialog_timber_truss.html

Please go ahead and test out the link I've given above.

If there are no major fixes then I am ready to implement this module into the plugin.

 

[Medeek]

This is would be the typical output of the html input for the timber trusses:

I may add in the L1 dimension and the heel height dimension.

EDIT:

No major complaints or concerns with the way I have it currently configured, so far. I've starting creating the ruby code that does the heavy lifting. By the end of the week I should have something ready to go for timber trusses.

My goal is to also add in the Queen Post and Howe configuration for timber trusses, these other two seem to be the most commonly used.

There is a number of ways one could arrange the bolts on these plates or even configure the plates. I am trying to come up with the mostly widely accepted method that will make at least 75% of the user base happy. Hopefully I can achieve that.

At another level I am really happy about this latest edition to the plugin, I now have a better understanding and comfort level with designing bolt connected timber trusses and I can better address local customer requests in this regard.

 

[Medeek]

The html webdialog is now integrated into the plugin and variables are passing correctly between the two:

Developing new modules, especially one with some many variables/inputs is a time consuming process.

 

[Medeek]

Version 1.9.7 - 08.26.2017
- Added king post timber trusses with bolts and metal plates.

There may be a few bugs to work out as I haven't had the time to test every possible configuration but it appears to be mostly working now. The metric version is not quite ready so the GUI defaults to the imperial units regardless of the template.

View model here:

https://3dwarehouse.sketchup.com/model/b9530289-89ff-40c4-ac55-754344864d3a/Timber-Truss-King-Post

I will add in the Queen Post and Howe configurations if requested by users and make any other corrections or adjustments as needed.

The permutations with this thing is ridiculous. The truss above has larger members with a wider plate width that allows for two rows of bolts.

 

[Medeek]

Looking at the code structure of the timber truss module and the html web dialog it doesn't appear to be too difficult to add in the Queen Post and Howe type truss. This addition will make this feature considerably more versatile and useful in my opinion since it should cover 90% of most timber trusses of this type used in residential and commercial construction.

I will make it a point to add in both additional truss types before moving on to something else.

Recently I have not had a lot of feature requests so please fire away.

The next big item on the list is the implementation of the straight skeleton algorithm and the ability to create any rafter roof shape, this is a big one. If I succeed, which I will, this should be tremendously valuable to many of the plugin users.

How to do this sort of thing for truss roofs becomes a bit more difficult since truss roofs are a bit more ambiguous and can be pieced together in a variety of ways. I think it is possible but I will need to give this one more thought.

The next big item which needs to be tackled is the ability to generate floor joists and trusses for any floor outline. I've already given this some serious thought and the path forward is clear to me but it will just take some focused coding time and debugging. Along the same lines, the ability to cut holes in the floor assembly (stairwells, access doors etc...) is also a hot item, I will address this at the same time.

Work on the Wall Plugin has begun in earnest but my free time right now is limited so meaningful progress is slow, especially as I am still devoting the bulk of my time towards the truss plugin.

I have exactly zero feedback on the timber truss module so I am curious if anyone has used it yet and if they are encountering any difficulties or other issues that they would like to see addressed.

- Is this feature useful?

- What would make it more useful?

- Would other timber truss types (timber rivets, etc...) be more useful?

Just because I find it fascinating and would like to add it to the plugin doesn't mean it has any real world utility, I've learned that through experience.

 

[MEngineer]

Medeek,

I am really impressed by your work and very interested in the opportunity to put your tools to work on some of my projects. I am especially interested in your recent developments associated with the timber trusses.

I cannot give you any feed back at this time as I am currently swamped with other priorities and have not had the opportunity to investigate your efforts at length. I hope that you continue with your developments (especially with the howe style timber truss) so that when the opportunity does present itself, the resources will be available for me to use.

Thanks in advance!

Charles

 

[Medeek]

Medeek,
I hope that you continue with your developments (especially with the howe style timber truss) so that when the opportunity does present itself, the resources will be available for me to use.

Charles

I will work on the Queen and Howe truss this next week and try to get it out the door as soon as possible. My biggest question with these plates is do I have it right? I'm using some examples I have from previous jobs and some other material and plans from some other structural firms but I am sure there is more than one way to configure these things so additional feedback would be valuable.

 

[Medeek]

Version 1.9.8 - 09.04.2017
- Added queen post and howe timber trusses with bolts and metal plates.

View model here:

https://3dwarehouse.sketchup.com/model/11b78080-be08-4492-805c-2d73c9871ec6/Timber-Truss-Yard

Timber trusses haven't seemed to garner much interest or feedback but I do feel like it is a worthwhile contribution to the plugin.

There is more to be done with the engineering side but I will move on to something else unless customer feedback brings me back to it.

The big prize right now is the straight skeleton implementation. I have been mulling this one over for at least a year now.

The truss yard now has 23 different truss types/profiles:

https://3dwarehouse.sketchup.com/model/828e8b19-fac1-418e-bc64-f00294f453d0/Medeek-Truss-Yard-5

 

[Medeek]

Version 1.9.8c
- Enabled option for F436 vs. F844 flat washers for timber trusses (in the materials tab within the global settings).

 

[Medeek]

Tutorial #6: Timber Trusses

View model used in tutorial here:

https://3dwarehouse.sketchup.com/model/38b48d10-1b18-46d5-8d6d-69bd446cdcd3/Timber-Truss-9