Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: 1991 NDS Values for Lumber

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Joe:

If  I understand you correctly, you are just plugging in the new NDS values
into the older code formulas. Or are you using the 1991 NDS formulas and
all of the adjustment factors that have to be considered?

Neil Moore, S.E.


At 03:22 PM 09/10/1999 -0700, From the desk of Joe Otto wrote:
>Everybody knows that the 1991 NDS published values for lumber which were
>significantly less than previously allowed.  I don't have any problems with
>this.  However, it has put a wrench into analyzing existing roofs.
>
>Calculations on existing roofs using the 1991 NDS values often don't work
>for the existing loads let alone any additional loads.
>
>Some jurisdictions require the use of the 1991 NDS design values on
>everything.  Others say that if it was built before 1986 you can use the
>"old" values.
>
>I think it would be helpful if there was a mandate made by those
>knowledgeable in the subject which indicated when the 1991 NDS values are
>required to be used in all jurisdictions.
>
>Any thoughts on this subject would be appreciated.
>
>Joseph M. Otto, P.E.
>Ireland Engineering
>Fremont, CA