Scissors Truss Design
Summary: A scissors truss provides the benefits of a vaulted ceiling in the same framing time as standard roof trusses. Structural engineers and special software customize the roof truss to your home roof pitch. Use standard trusses in part of your home and the scissors trusses or another special truss in other sections. Explore all truss options with your builder for custom results.
Scissors Truss Design
A scissors truss is a really cool roof framing option. You not only get the speed of framing that you get with common trusses, but also the added benefits of an interior sloped ceiling. The slope of the interior ceiling is always controlled by the slope of the exterior roof surface. The companies that fabricate the trusses use sophisticated software to design the trusses. You provide the span of the roof and the desired exterior roof pitch and the software does the rest. You can ask the structural engineer at the truss fabrication plant if there is a way to increase the interior slope, but I doubt you will get much more than one half the slope of the exterior roof surface.
Remember you can mix and match trusses! Over part of your home you can have scissors trusses, while over another part you can have common ones and over the garage you can have attic or storage trusses. The cool thing is that from the outside no one would ever know since the exterior roof slope of all the trusses is identical. Ask your builder to explore all truss options!
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Comments:
Randi Lansford 12 Dec 2007, 14:56
Hello - I have a house in Nampa, ID. It has a cathedral ceiling from back
wall to overhang on front porch with the bearing walls being the back and
front walls of the rectangular house. I want to bump out the back along
about 2/3 of that back wall. Plan is to knock out the interior walls
between a small back bedroom, small dining area and kitchen, add about 11
feet along their common back wall and make a 30x20 great room. I would like
the new cathedral ceiling portion to run at right angles to the existing
roof line. The ceiling of the kitchen - the last 1/3 of the new area will
be flat - at 9 feet. The original home builder tells me that sissor tresses
were used in the roof and he feels that will be a possible deal breaker.
Might you have any suggestions? Can the tresses be supported closer to the
top point, then reinforced and cut to redirect the pitch of the ceiling to
cover my extra 11 feet? Any help you could give would be really
appreciated!!
AsktheBuilder 15 Dec 2007, 08:10
Randi,
Take photos of the inside of this room and the outside of the house. Then call the closest truss fabrication plant. Ask the on-staff engineer if you could stop by for a chat about your photos.
Nadeem Thakur 24 Dec 2007, 02:18
Hi Tim,
This is Nadeem Thakur from Mumbai,India. Hope you are doing fine. I have a question. I am building a Factory Shed and I just want to know the design of the truss whihc 60 Ft wide. I would highly appreciate if you could please help me design this truss. Awaiting your reply. Thanks and Regards Nadeem
Harvey 13 Apr 2008, 19:41
How do I attach the scissor truss to the wall top plate?
Bill Leiper 14 Apr 2008, 09:40
I am in the process if building a 20 meter wide building and want to use
trusses. This building is in Ecuador at a wood products plant. We´ve
built some 11 meter trusses, but I need to see how I would design the
longer trusses. Is there a formula or a tutorial that I can use? What I
am looking forward to is a design.
John Cavandish 29 Jun 2008, 18:40
I have a porch with a vaulted roof. The porch is 8' wide/14' long/10' high
at the center. The walls are 82" all around. The slope of the roof on
each side is 30 degress.
I want to build a vaulted ceiling but I'm not sure what the distance should be between the roof and my new ceiling. Please note, I live in the twin cities and the winter gets cold. John C
Ehren Stellrecht 04 Aug 2008, 08:13
What is a Post and Beam Truss? I regret that this may not be the exact
term I heard used.
Troy Roberts 21 Aug 2008, 20:54
Yes I'm inthe process of adding on a rather large addition. It will be 13'
x 34'. My question is I would like it to be a cathrel ceiling running the
length of the 34 foot room. what is the max length that a scissor truss
can be.
craig 27 Aug 2008, 16:54
FYI. Wood trusses are engineered products that have to be designed per job
based on local building codes and the building designer's or owner's specs.
Trusses can easily free span 50+ feet, but the longer the span, the more
care must be taken in installing and bracing. I design trusses for a
living, and I can tell you that I do not recommend trying to build your own
with plywood gussets and nails unless you have had a licensed engineer
design them. Otherwise, go to your local truss manufacturer and have them
design and make them for you. Trusses can be used to do a lot of things,
but they MUST be properly designed by a trained professional or serious
problems WILL occur.
Troy C 27 Aug 2008, 23:46
I am building a roof over a new 10 x 8 porch and want to use scissor
trusses with open end to show off the entry door and transom. I am using 8'
pillars under 2x6 beams.I need to know what pitch scissor truss to order to
clear the 9' center of the half circle transom?
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