×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

1907 Lumber Values.

1907 Lumber Values.

1907 Lumber Values.

(OP)
The Carnegie Pocket Companion-1923 which SlideRuleEra has talked about before, gives design values for wood.

Those design values are quiet high, so I am unsure of how to apply them for use in evaluating wood from a building built in early 1900. Does anyone have any suggestions?

I am trying to get an estimate of what design values may have been use in order to determine the orginal loads that a building was designed for.

RE: 1907 Lumber Values.

- rule of thumb is wood that old is select structural or dense select structural.  You can get the species through your local APA or agriculture extension office.

RE: 1907 Lumber Values.

RARMBJ - The note at the top of the table of "Working Unit Stresses for Structural Timber" (page 289 of CPC-1923) gives this guidance:

Quote:

For building and similar structures, in which the timber is protected from the weather and practically free from impact, the unit stresses may be increased 50 per cent.
I agree that this would make the allowable working stresses quite high by today's standards. Engineer's in the early 20th century do not appear to have had knowledge of "load duration". I have never seen that issue even discussed in publications from that time. Also they were willing to accept a much smaller safety factor then (typically 6 to 1, and if the 50% increase is taken into account it becomes only 4 to 1). This probably had to do with the fact that almost all timber used at that time was high quality, not the wider variability seen today.

In summary, IMHO, for a building that meets the above requirement, I would apply the 50% increase. This would be to determine what the ORIGINAL design loads were. But... I certainly would not say that the structure is safe (by today's standards) at those loads.

www.SlideRuleEra.net idea

www.VacuumTubeEra.net r2d2

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources