Truss Calculators

Started by Medeek, March 12, 2013, 06:33:08 AM

Previous topic - Next topic

0 Members and 6 Guests are viewing this topic.

Medeek

Raised/Energy heels add another level of complexity to the equation.  Below you can see that various heights of a raised heel on a simple King Post truss requires different configurations and hence separate plating routines:



This also affects the gable trusses as well, below is a fink truss with its gable counterpart:



View models here:

https://3dwarehouse.sketchup.com/model.html?id=91d8d78a-8e6c-4dab-9839-4d689c84c297
https://3dwarehouse.sketchup.com/model.html?id=89739563-049f-4277-bfca-75663724967e

I'm still house cleaning.  I've now got the King Post and Fink truss fully cleaned up with connector plates enabled for all possible configurations (raised heel, non-raised heel, structural, non-structural).  I've only got 10 more common truss types to work through, see list below:

Queen Post
Howe
Fan
Mod Queen
Double Fink
Double Howe
Mod Fan
Triple Fink
Triple Howe
Quad Fink

Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Version 1.7.9 - 01.15.2017
- Enabled metal plate connectors, materials and custom layers for the common king post and howe trusses.
- Added energy/raised heels for howe truss (3 variants: wedge, slider and vertical w/ strut).
- Metal plate connectors now enabled for king post, fink and howe raised heel/energy trusses.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer


Medeek

I'm still investigating "real world" applications of the plugin to determine where the weakness and deficiencies are.  Here is an example combining a dutch gable rafter roof with some raised heel trusses.  Now that the raised heel feature is fully active for many of the common trusses it is actually quite easy to measure and then match the heel height of the rafters.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=461e63b6-4965-4697-b864-a9fbe464d53a

I am interested in how others are actually using the plugin and where it is falling down for you, please feel free to send me models or post on the forum with your "real world" design issues with regards to the plugin.  This will help drive future development and prioritize the more important items on the todo list.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Don_P

Sweet, that will make it easier to tune in the overhangs and fascias between roofs. On a complex roof I'll start from the fascia line fairly often and work backwards from there.

Medeek

Raised heel double fink truss with connector plates:



I added this one today and will roll it into verson 1.7.9b.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer


Medeek

Another item I have been putting off is the heel blocking.  I'm planning on offering two variants (vertical and angled), with the option to draw in the ventilation holes (typically 2" in diameter in my region, with 3 holes per 24" o/c spacing) if desired:



Obviously this is not a hot item since no one has bugged me about it but I have not forgotten it, just put it aside up until now.

With raised heels this may become a bit more complicated requiring more options, (ie. a V-cut instead of the typical bird holes).  More input from builders would be useful in this regard.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Don_P

We typically do boxed soffits so I run the blocking short heighthwise 1.5-2".
Raised heels will get into where lateral bracing is required, if possible it might not be a bad idea to have the program alert you.

Medeek

I've got the plywood material working quite well in the plugin, and the ability to toggle between it and OSB in the global settings.  I have a few more other features and edits and then maybe I will role a revision tomorrow or Sunday.



I actually like the plywood look much better than the OSB.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

OSB or Plywood will now be an option for the floor sheathing:



The new sheathing tab in the global settings:



As time goes on I will probably add in more options for wall cladding and interior wall cladding (ie. gypsum) as well as the ceiling logic I discussed in a previous post.

I'm now working on the gable end wall sheathing option and the roof cladding option.

There are also two new options in the "General" tab which allow one to toggle the default setting for gable end trusses and advanced options (roof, floor etc...).
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer


Medeek

Version 1.8.0- 01.22.2017
- Enabled roof cladding for common trusses.
- Added nine "IKO Cambridge" architectural shingle colors into the roof cladding material library.
- Added "plywood" material for roof and floor sheathing.
- Added a "Sheathing" tab into the global settings.
- Added entries in the "General" tab of the global settings to toggle default settings for gable end trusses and advanced options.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=408cd4f0-26b0-416f-bcd0-c14e5565c97a

Initially I was just going to texture the exterior face of the sheathing for the roof cladding but then I realized that there may be cases where there is roof cladding but not sheathing or vice versa.  In the end I went with a separate layer, material and extrusion for the roof cladding, this allows one to get more granular with the structure and in my mind closer to reality. 
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Trying to find a good wood shake or shingle roof texture, this one is pretty good except for a bit of banding:

Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Thinking about sheathing and cladding advanced option for the valley truss set.  Typically the valley truss set is placed on top of the main roof sheathing:



View model here:

https://3dwarehouse.sketchup.com/model.html?id=c8b9995c-1649-4f2a-a769-9fdb685d0913

If I create the sheathing and cladding just right then it will be easy for the user to manually trim the secondary roof sheathing and cladding with my trim tool and then optionally union them up with the built in Union tool.  I may need to make a video showing exactly how to perform this task.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

The valley truss set now has sheathing and cladding added as an option.  You still have to manually trim the secondary roof's sheathing and cladding and then union it to the valley set's but with the trim tool this is very simple to do:



View model here:

https://3dwarehouse.sketchup.com/model.html?id=164baabf-f312-42b5-a1a9-97e7d8557dcf
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Here is the example building with the various layers in an animation.

https://youtu.be/uleFjJ5UQjk
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer


Medeek

Call me crazy but I want to build something like this on my 10 acres so I can see all the way to the beach.



Given my wind speed (155mph ult.) and seismic zone (D2) I am probably looking at some serious holdowns at the first level (HDU 11).  I would have to run the numbers but it would probably work.  I would probably also sheath it with 5/8" plywood inside and out for some serious shearwall action, at least on the the first two floors.  I would probably also frame the first two floor with DF No.2 2x8 studs or 2x6 studs at 12" o/c.  I'm thinking spiral staircases between levels to save as much floor space as possible and to make it more interesting.  Minimal windows on the first three levels and then the top level would have a lot of windows for the view.  11-7/8 TJI 210 for the floors with 3/4 sheathing T&G, 16" o/c. 

The structure is 16'x16' with grade to top plate height of 38'8".

The roof is 6:12 pyramid hip with 2x8 rafters, I may go with a steeper pitch though.

On a structure like this overturning is a serious threat, I would need to check the dead weight of the structure and see if the seismic or wind forces could potentially lift the foundation right out of the ground.  The solution is to increase the dead weight of the structure especially at the base, by upsizing the footing and stemwall.  You will notice my stemwall is 10" thick, 36" deep and a 24"x12" footing, even this may not be enough.

Anyone design something goofy like this before.  I don't know if my county building dept. would give it an approval though even if its engineered (stamped).
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Don_P

I think I'd look at the forest service firetower designs rather than platform framing it.

Medeek

Probably cheaper to build.  I was thinking outside of the box on this one, maybe too far outside of the box.

Both my wife and I would like a secondary storage structure and my wife was wondering if I could add some sort of perch onto the house so I naturally thought why not combine the two ideas...
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Since I have now have roof cladding enabled I figured it only made sense to have some sort of wall cladding enabled for the gable end walls:



The advanced options now allow one to specify wall cladding, the settings can be adjusted in the "sheathing" tab of the global settings.  I currently only have 4 different colors of Hardiplank Siding but I will add more as requested and I can find textures that I like or create.  It should also be noted that it isn't too hard to swap out the texture for the user's custom textures.

I'm also thinking about adding an option for an air gap between the wall sheathing and the wall cladding in the case that someone wants to use brick as their cladding option.  For standard veneer brick in the US the air gap is usually 1" if my recollection is correct.

I will try to roll these latest additions into a new revision here shortly.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Version 1.8.1 - 01.29.2017
- Enabled gable wall cladding for common trusses.
- Added four "HARDIPLANK Cedarmill" siding colors into the wall cladding material library.
- Enabled sheathing and cladding for valley truss sets.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Here is a simple structure created with the Truss and Foundation Plugins along with Housebuilder:

https://youtu.be/V-wUQrYOLOk

I like Housebuilder but I really feel like I need to develop my own Wall Plugin since it will tie in better with my Truss Plugin and allow the user to create the different sheathing and cladding options on the same layers.

Creation of the foundation and roof both took less than 30 seconds to create.  The walls, windows and doors did require manual editing.  I also realized that it would be useful to allow the option for wrapping the floor framing in wall sheathing and cladding so that this can be unioned with the appropriate sheathing and cladding on the walls above.  I will add this into the Todo list.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer


Don_P

Thinking out loud. I orient wall sheathing upright normally(option), typically hanging it below the mudsill about 1/2" (option), and I typically block with 2x4's flatways (option)

Medeek

When combining different roofs on complex structures I often find myself having to delete the outlookers, overhang and gable end truss on one end of the roof assembly. Then today I had a request from a user to enable the ability to limit the gable geometry to only one end. Based on this I will try to set up another option for the gable end truss option which allows for only the creation of one side with the gable end geometry. This means I will have to rework some of the advanced options to make sure it is compatible but I think I can make it happen fairly quickly.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

In response to a recent request about gable ends of the roof assembly I have created an additional option in the "Gable End Trusses" option when creating common trusses.  The new "Front" option only creates the gable end truss and gable end geometry on one side of the truss assembly and leaves the other side open as shown below:



This should come in handy when creating roof assemblies that butt up against walls and other complex configurations (ie. T-shaped buildings requiring Valley Sets etc...)

I've also been slowly working away at bringing all of the common truss types up to speed.  The Modified Qeen Truss (Mod Queen) now has plates, raised heels, structural outlookers, layers and materials:



Most of the non-common truss types still need me to go through and integrate plates, layers, raised heels and materials, the amount of work needing to be done is staggering.  This plugin is far from a polished, finished product, even after more than a year's worth of time and effort.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

I'm quite familiar with all of the industry names for various configurations of roof trusses (ie. Fink, Howe, Mod Queen, King Post, Queen Post, Double Fink etc...)  What distinguishes these trusses from each other is the configuration of the webs of the truss which is dictated by the number of panels of the top chords and bottom chords.  For example the Howe truss is four top chord panels and four bottom chord panels (4/4).  Most diagrams show up to a Triple Howe truss (8/8).  What is not typically shown is an (8/6) and (8/7) truss, is there any reason for this?  These two configurations seem perfectly valid to me, I would call them a Triple Queen and Fan Fink truss respectively.  Has anyone come across either of these two configurations?
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Actually I would change the name of the Fan Fink to Double Fan.

The next size up would be:

Quad Fan 10/5
Double Mod Fan 10/6
Triple Fan 10/7
Quad Queen 10/8
Quad Fink 10/9
Quad Howe 10/10
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer