A Curved Truss?

Once again we are working on a unique project with a series curved glulam trusses with douglas fir struts.  As you move back into the structure the span of the truss decreases and the roof slopes down.  So, because of the curve each truss is similar in appearance but unique.  The architect on this project came up with a truncated cone on it's side for the geometry.

Here is the outer most truss on it's own.  The rods that you see sticking out of the top of the truss are there to attach the rafter system to.  When finish the roof system will also be curved.

This image shows the rest of the trusses in the structure.  You can see the change in the geometry in this picture as well.

I just wanted to share something unique that will be going through the shop.  As always, visit Vermont Timber Works website. 

A Sampling of Timber Trusses

Well, it has been a while.  Things have been busy, which is a good thing.  So, to catch up have put together several images of the truss that we have been designing.  Many different shape and sizes and that's what keeps my job interesting.

This truss is actually a bent view of a cedar pavilion that we did.  Even the curved pieces are cedar.  Actually, they are cedar glulams.  You can see at the end of the top chords the slope of the roof changes pitch.  We accomplished this detail by cutting the top chords down out of a larger timber.

This is a very traditional scissor chord truss.  These trusses are still in the design process, that is why you don't see any pegs or bolts on the surface of the truss.  This job is out of rough sawn white oak.

 Here is another more traditional scissor chord truss with the joinery shown.  This truss has a more shallow pitch than the previous truss.  Douglas fir #1 or better was used.

This is a decorative truss that we designed out of pine.  This is also a scissor chord truss but the bottom chords don't extend out to the exterior wall.  This truss also has a could of decorative finials.

Here is yet another scissor chord truss out of douglas fir timbers.  I guess I didn't realize how many scissor chord truss that we have done recently but that's okay because they are all very different.  They all do vary in size, material, loading, and configuration.

So, that's a little look at what we have been up to.  There are many more barns, homes, restaurants, and pavilions that we are working on.  Make sure you check out Vermont Timber Works and see what's new (besides the website).

Timber Truss with Double Chord

This truss has a double top and bottom chord and all of the webs and steel are sandwiched between them.  Because this truss is located in an area that has high wind loads, the steel was changed from rods to pipes.  The pipe can take the compression forces when the truss reverses in a high wind situation.  The truss material was specified as number 1, closed grain, redwood.  Are you wondering what the difference is in open and closed grain?  Check out The Nature of Wood for more information.

If you want to see more trusses like this, visit Vermont Timber Works.

Modified King Post Trusses

This week I'm working on the design of a modified king post trusses.  The trick to the modified king post truss is the design of the top chord.  Depending on where the tie is placed and the how much tension is being transferred it adds to the bending stresses of the top chord.  This typically increases the size of the top chord.

The image is from cadwork which is the drafting software I use.  Here are some other examples of modified king post trusses from Vermont Timber Works.