Wind Loading
Wind Loading
(OP)
I was looking through the OBC, and realized that values for q, Cp and Cg were not given. After getting the NBCC, I found the q value, but the Cp and Cg values were still missing. I realized now the values I need are in the NBCC Part 4 Structural Commentaries. Does anyone have the wind section that they can share as an attachment; or knows a link to where it can be downloaded?






RE: Wind Loading
Next, a few comments on your posting:
1. This is an international forum, so please be clear when you use acronyms. I will assume OBC means Ontario Building Code and NBCC means National Building Code of Canada. This will allow others to help you with a more pointed and appropriate reply. I am not familiar with either, so it would not be appropriate for me to offer a technical response.
2. Cross posting is against the rules of the forums. You have posted the same query in 3 different forums. Please select the appropriate forum and post your question or comment there. This forum is the appropriate one for your question. I have red-flagged the other two.
3. The documents you requested are protected by copyright and cannot be posted in the forums. You will have to purchase them or make a trip to a local library for reference.
Good luck.
RE: Wind Loading
RE: Wind Loading
Assuming you are in Canada, it is one country that respects copyrights. Yes, some countries allow downloading copyrighted documents...my personal opinion is that this is wrong. A lot of effort goes into the preparation of such documents. That effort costs money and provides jobs for some people. To circumvent the payment for such documents puts all of that at jeopardy.
Preaching done.
RE: Wind Loading
It's $94 and downloadable immediately at the nrc site. In your jurisdiction, as well as most others, using or possessing copyright material or pirated software in a professional office can result in your license being suspended. You are really dead in the water generating NBCC/OBC wind loads without the standard.
RE: Wind Loading
Just because someone needs something once, doesn't mean they shouldn't be doing it. Remember, we all need to start at square one before we got to where we are now. As far as I know, Canada is a country that allows downloading from the internet, as do many other countries. In my opinion, if someone wants to support the preparation of documents and the entrepreneurial spirit, they should make a donation, or speak to the appropriate authorities to make the changes to the laws that they want. At the end of the day, preaching to me will not change the laws, and gets little done for your cause. But in my view, I support the laws, because I think free access has allowed people to resources they never had before, and made people more knowledgeable, which is a positive benefit. But I will try my local library as you mentioned; but still hope someone can come forward to help me and others out with this particular "missing" resource.
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BA
RE: Wind Loading
If I recall correctly, to become a P.Eng. you need to have graduated from an accredited university and write an ethics exam upon gaining appropriate experience. Did that not sink in?
Good luck.
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It doesn't matter what your profession is, everyone needs to follow ethics in their profession, regardless if you are an engineer or not. If you have an ethical issue with the laws, you should have your voice heard with government. You are pointing fingers at the wrong people, and passing judgement about internet laws; but I can understand everyone has their own opinion. In my opinion, the internet has created a wealth of information, which is unfortunate that you don't want to take advantage of, and I think you are being left behind. The biggest consumers of these products are businesses, which is why downloading privately has never been a concern for the governments.
BAretired..I respect that you don't want to waste your time scanning information, but my query is for people who have the resource.
This thread has now changed to a discussion about the ethics of the legality of downloading information from the internet. Unfornutately, I don't see an appropriate place on this forum for this discussion, or I would create a new thread. Again, if someone knows of a link to my original query, then please do share.
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BA
RE: Wind Loading
I'm a published author. If my material is pirated, it reduces my income from that material. How would you feel if your income were reduced because someone took something from you illegally?
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Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
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Ron...It's legal to download copyright material in some countries, so I don't understand why you consider it an infrigement at the same time. At this stage, you only hold a view or opinion that it's wrong. As a publisher, you decide if you want your material to be in electronic format. You clearly understand the risk of it being distributed over the internet when it's in this format; (and you also understand that material will be distributed over the internet, because everyone has access to the internet nowadays). From a business point of view, you make the decision to make it available in this format because you know that you make more money from businesses inspite of it's availability. Also, you make money through lawsuits of businesses and schools that clearly infriged the copyright laws for using this material for business/teaching purposes (this needs to be distinguished from private use). If someone downloads something legally, and uses it without distribution or re-sell, then it's classified as personal use, whether or not it has translated it's effect in their work or career.
Concretemasonry...thanks for your comments, as this is the only response I got related to my post. The provincial code does not have any guidance related to q and CpCg values, which means someone must get both the National Code (for q values), plus the User Guide (for CpCg values), just to calculate wind loads (I think I'm not the only person who encountered this problem). I'm missing the third installment (the User Guide), and hoping someone can share.
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http:/
http://pu
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Wind Loading
I was merely responding to your "appropriate place on this forum" question.
Then you say:I have no intention of starting a new thread on this topic as the answer seems clear.
In Alberta, the q value comes from the Alberta Building Code. I would imagine it is the same in Ontario, but I don't really know because I don't reside in that province.
The CpCg values come from the User Guide which you can order on-line at www.nrc.gc.ca/virtualstore or you can Telephone 1-800-672-7990 or 1-613-993-2483.
BA
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BA
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BAretired...the same is not for the OBC. They don't have q or CpCg values in there. The q is in the National Building Code. CpCg is in the User Guide. For someone to calculate wind loading for Ontario, they must have all three books. Nice profit making idea, but I guess that's life.
woodman88....those are great links. Is the net pressure coefficient values in the International Code exactly the same as the Canadian CpCg values?
But still hoping for the User Guide, if someone has a free public link (filesharing link) for that.
RE: Wind Loading
You are incorrect, the q values are contained in the Ontario Building Code, in the compendium, which is another volume sold separately. Looks like you are going to have to add another publication to your list.
RE: Wind Loading
From the following government website I found the Cg factor.
http://ww
Which gives the following statements (Though I wonder why it gives no guidance for Cp)
"Section 4.1.7. Wind Load
4.1.7.1. Specified Wind Load
(1) The specified external pressure or suction due to wind on part or all of a surface of a building shall be calculated using the following formula:
p = IwqCeCgCp
where,
p = the specified external pressure acting statically and in a direction normal to the surface, either as a pressure directed towards the surface or as a suction directed away from the surface,
Iw = importance factor for wind load, as provided in Table 4.1.7.1.
q = the reference velocity pressure as provided for in Sentence (4),
Ce = the exposure factor as provided for in Sentence (5),
Cg = the gust effect factor, as provided for in Sentence (6), and
Cp = the external pressure coefficient averaged over the area of the surface considered.
..."
and "...
(6) The gust effect factor, Cg, shall be one of the following values:
(a) for the building as a whole and main structural members, Cg = 2.0,
(b) for external pressures and suctions on small elements including cladding, Cg = 2.5,
(c) for internal pressures, Cgi = 2.0 or a value determined by detailed calculation that takes into account the sizes of the openings in the building envelope, the internal volume and the flexibility of the building envelope, or
(d) if a dynamic approach to wind action is used, Cg is a value that is appropriate for the turbulence of the wind and the size and natural frequency of the structure."
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Wind Loading
Unfortunately, that is not how the system works today. There was a time in Canada when codes were free to any and all users. That was because codes were subsidized by the cement companies, steel companies and other affected industries. But it got too expensive, so they stopped doing it a number of years ago.
The document you require is available at a price (I don't remember what I paid, but it was not very much). I don't know of any way of obtaining the document other than buying it.
BA
RE: Wind Loading
You must be new to the internet and the related search engines associated with the internet because I found the file you wanted in less than a minute. I buy my codes and standards because I need a legal hard copy in case there is ever a legal dispute over one of my designs where I referenced the code. In my neighborhood the going rate for an engineer is between $80 to $150 USD per hour. It sounds like you could have purchased the documents you wanted to steal several times over for the effort you are expending.
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(By the way, I don't receive ANY fees for my work on the code, which is all pro bono. I even have to pay my own air fare and hotel bills when attending meetings out of town.)
However, at present, the codes have to be paid for. Deal with it. If you download and use something for private study or a hobby project, that is one thing. If you use it for designing something that you get fees for, that's a different thing entirely.
How difficult is it to add the cost of a code to your fees?
RE: Wind Loading
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Wind Loading
woodman88...That's an interesting link. It appears to be the same as the OBC clauses. As you mentioned, it doesn't tell you the Cp values; and many other values are missing. In fact, the User Guide that I am looking for tells you the CpCg values together, so I have no idea how someone is suppose to use the OBC information on it's own with all the missing information.
CRG...Can you tell me the search method you used, or share the link?
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I won't help you break copyright laws. I would hope the moderators on the site would kick anyone off if they did. In fact, I am a little surprised that this thread hasn't been red flagged because you are asking for folks to break copyright laws and ignore basic ethical principles.
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For this reason I feel that the commentaries are deliberately left out of the document so they can double charge you for the information they should be giving you in the first book.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Wind Loading
woodman88...I agree with you, the commentaries are only a guide that you use at your own risk. But I don't know of a better resource to use, so I think everybody is stuck in using it.
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BA
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RE: Wind Loading
BAretired...Good point, they are referenced; but unfortunately they don't provide the CpCg values in the same place.