Codes and Standards - Timber Engineering Forum https://timberengineering.org/community/codes-and-standards/ Timber Engineering Discussion Board en-US Tue, 05 May 2026 16:03:06 +0000 wpForo 60 Glulam with tension side milling/notches - Code Alt Design Method https://timberengineering.org/community/codes-and-standards/glulam-with-tension-side-milling-notches-code-alt-design-method/ Sun, 09 Mar 2025 01:52:21 +0000 There are situations where architects desire a tension side milling in lumber laminations of glulam beams, glulam planks, or NLT.   Doing this is not allowed per NDS or ANSI 117 as the lamination grades are voided.  Same is true for NLT lumber laminations which are graded to WWPA or PLIB.  That being said, the NDS (2024) Section 3.1.2 "Net Section Area" can mislead some engineers to think you just design for the net section.  I've confirmed this is not true with AWC Staff and APA Staff and WWPA Staff.  Does anyone have a suggestion on how to approach this issue with a Code Alternative design method, or testing methods to demonstrate safe design?  Examples shown below. 

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]]> Codes and Standards HEBlomgren https://timberengineering.org/community/codes-and-standards/glulam-with-tension-side-milling-notches-code-alt-design-method/ Statistical properties of the NDS Supplement values https://timberengineering.org/community/codes-and-standards/statistical-properties-of-the-nds-supplement-values/ Thu, 06 Mar 2025 15:51:50 +0000 When I study EuroCode, it is quite clear that EN1990 requires an explicit probability of exceedance value for strength of the material listed. If memory serves it is set at 5% (5th percentile) for characteristic values, which means if you pick up a wood and test it, there is 95% chance your test value will be higher than what is used in design (so design is conservative).

Do we know what is the statistical information on the values listed in NDS with regard to testing results? @drammer  

]]> Codes and Standards Shiling Pei https://timberengineering.org/community/codes-and-standards/statistical-properties-of-the-nds-supplement-values/ National Code vs. EuroCode question https://timberengineering.org/community/codes-and-standards/national-code-vs-eurocode-question/ Fri, 29 Nov 2024 11:00:25 +0000 I was teaching EuroCode 1995 in L'Aquila for some international students. While it is a good experience for these students who dont know anything about Eurocode (and myself), it looks like in Italy, there is another National code that people use in real project. By EU law the national codes must be "exceeding" and "compatible" with EuroCode. This makes some sense as it is similar in case of IBC vs. California code CBC, where a local code can take the model code and modify it a bit based on local condition such as seismicity.

However, there is a National Annex system for EuroCode that allows individual nations to add something when adoption Eurocode. Is that the National Annex of Italy or is it a different code?

So could anyone help explain this system a bit more for Italy? @angeloaloisio

]]> Codes and Standards Shiling Pei https://timberengineering.org/community/codes-and-standards/national-code-vs-eurocode-question/ NDS vs. EuroCode https://timberengineering.org/community/codes-and-standards/nds-vs-eurocode/ Fri, 25 Oct 2024 10:14:09 +0000 I have always heard good things about EuroCode, but never had a chance to look into it.

I had the opportunity to teach EuroCode 1995 during my Sabbatical in Italy. So I was able to look into it briefly. I am by NO means an expert, but more like an entry-level user. These are some differences that strike me:

1. EuroCode is more reliability based

It is true EuroCode is sitting on a more robust reliability based framework, thanks to the EuroCode system. In fact, EN 1990 is a LRFD-type (they call it Partial Factor method) framework that ties all codes together. Pretty neat! 

The U.S. code... we all know the LRFD format is back-fitted using ASD. The design community has a very strong ASD tradition. I believe the difference here is more historical than merit.

2. NDS is more prescriptive

You got tables and simple design checks in NDS. The standard connections are all tabled up for you. The NDS came with the NDS Supplement. You have SPDWS giving you the unit shear value of different nailing patterns.... Grab and use!

You have NONE of that in EuroCode 1995.... It is more of a behavior-based code with different stress and stability checks. On the positive side you can be very flexible and design for all kinds of situations. On the negative side you dont have table to look up for simple, standard applications.

3. NDS is more accessible

Well, you can view NDS and NDS Supplement online for free. EuroCode is behind paywall. Even if you get EN1995, you still need to get individual standards for material properties...

 So in summary, I feel NDS is easier to use and learn, students can implement it more as a handbook. On the other hand, EuroCode needs a better understanding of reliability background, but is more flexible (for a price that the engineer needs to know what he or she is doing...) 

]]> Codes and Standards Shiling Pei https://timberengineering.org/community/codes-and-standards/nds-vs-eurocode/