Latest Discussions : Miscellaneous

daydreamer99701

02:48AM | 12/01/04
Member Since: 11/30/04
3 lifetime posts
I am interested in finding plans for roof trusses. If anyone would know of any websites that give detailed, comprehensive information could you please pass this along.

In case anyone is wondering why I don't just buy trusses its because I want to strengthen rafters that are already in place and would like to determine how much webbing and what angles to place them at.

And, yes, I have consulted with several builders about this and have received a varity of answers which is why i'm hopeing to find a web site that explains truss construction concepts.

Thanks

Glenn Good

04:29AM | 12/04/04
Member Since: 09/10/03
314 lifetime posts
You are not likely to find a website that will give you the specifics of truss constructions for 2 reasons:

(1) Trusses must be designed by an engineer to meet specific load and span requirements unique to each specific project and location and the design drawings must be stamped with his/her professional seal.

(2) The calculations for truss design will vary in different parts of the country due to varying weather and geological conditions. For this reason, the engineer that does the design drawings and calculations must be licensed to work in the state the project is in.

Glenn

Moderator: Construction Systems, Foundations, and Masonry & Stone

For more information about me and/or my qualifications please visit my website at:

www.consultationdirect.com

daydreamer99701

05:19PM | 12/11/04
Member Since: 11/30/04
3 lifetime posts
Thanks for the answer. I was able to find several web sites that provided some very good information. I also found a person that was very familar with both truss design and the type of remodling project I am doing. He was able to give me the information that I needed.

I was rather suprised to learn that while trusses need to be designed by a engineer, a regular rafter roof system does not have very stringent codes. At least not in my area.

Thanks for the answer,

Craig

Piffin

02:52PM | 01/09/05
Member Since: 11/06/02
1278 lifetime posts
Glenn,

Another reason why this is a tender subject is that the weak link is the point of connections (gusset plate connectors) and it is nearly impossible to match the stresses gained buy the pressed pieces at truss plant when doing it by hand in the field. Even with site stick framed roofs using rafter ties, the pioint of connection is the weak link and often igniored, using onluy three sixteen penny nails at each, which is certtainly inadequate.

But if he has a roof structure in failure now, it shopuld be easy enough for any competent carpenter to come up with something to improve it.

Excellence is its own reward!


Glenn Good

04:50PM | 01/09/05
Member Since: 09/10/03
314 lifetime posts
Piffin,

True the connection points are the weak points in a roof truss. The nailess plates could possibly be replaced by structural plywood gussets secured with good quality wood glue and many 4d common nails. Many trusses were originally made in this fashion before the nailess plates were developed.

The main drawback is in the design. Without first hand knowledge of the local building codes, and possible problems posed by the geographic location of the project, a truss can and should not be designed through a website or over the internet.

I have designed and built trusses using plywood gussets in the past and they worked well and are still holding up after 14 years with no sag. I would never, however, attempt to design a truss to be used on a project that I do not have first hand knowledge of, and can not oversee the construction.

Glenn

Moderator: Construction Systems, Foundations, and Masonry & Stone

For more information about me and/or my qualifications please visit my website at:

www.consultationdirect.com


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