ASCE 7-10 Components & Cladding

Online Wind Load Design Pressure Calculator Help

This article provides help and documentation regarding the Engineering Express ASCE 7-10 Components & Cladding Wind Pressure Calculator (Classic). Most questions can be answered just by watching the video tutorial below, but if there are still unresolved issues, please read through each section by clicking on the titles below to display them.

YouTube Video Tutorial

Can’t see the video? Click here to view it on YouTube.

General Use

This calculator is intended for use in calculating required wind load design pressures given certain inputs. It is also a primary means of submitting a design pressure project to us. Except in the case of printed and signed calculations, Engineering Express shall not be held liable for its results.

Submitting Projects

To submit a project, first make sure that all project information is correct, including building location and openings. Once certain that no changes need to be made, click on the “Submit Job” button at the top of the calculator and follow the instructions.

If you want to submit multiple projects (or a single project in multiple parts), you must refresh the page in order for the calculator to generate a new project reference number. Submitting more than one project at a time is not supported because for each reference number the latest submission data will overwrite any previous data. You can utilize the “Local Save/Load” button to temporarily hold your projects before refreshing the page, but be aware that all locally saved projects are reset every time the calculator is updated. These are both known limitations and we apologize for any inconvenience.

NOTE: The calculator will NOT send an e-mail to us automatically. This is the most common mistake we encounter. In order for us to receive your design pressure job request, YOU must send us an e-mail with the information provided in step 3; the calculator simply attempts to make the process simpler for you.

Frequently Asked Questions

Why can’t I see the calculator?
The most likely reason is that you do not have the latest version of Adobe Flash Player installed. You can probably find it on Adobe’s website. You may also want to try updating your browser to its latest version.

What’s the deal with ASD and LRFD?
In most cases, ASD (Allowable Stress Design) will be used over LRFD (Load Resistance Factored Design), but for an explanation, please see our article on the matter:
Engineering Express Deciphers the Mystery of ASD vs LRFD

Well what about K_d?
For K_d (Wind Directionality Factor), 0.85 is the accepted value for Components & Cladding under ASCE 7-10 and 2010 FBC. We offer the option for 1.0 just in case you want more conservative values.

I can’t make heads or tails of Exposure D.
That’s not strictly a question, but it’s an important point so I’ll explain. ASCE 7-10 now includes Exposure D, a change from ASCE 7-05. A rule of thumb for Florida coastal regions (very quick summary, not to be taken as law): if a building is within 600 feet or 20 times the mean roof height, whichever is greater, of the coast, the building is in Exposure D. For a more detailed explanation, see Exposure D – How Does it Work?

Why can’t I make the Default Opening Elevation higher?
This is probably because the Default Opening Elevation (z) is limited to being less than or equal to the Mean Roof Height (h); an opening can’t be higher than the roof.

How is the End Zone (a) calculated?
The End Zone, or the distance from the edge of the building which is considered zone 5, is determined by taking 10% of Minimum Building Dimension (L) or 0.4 times Mean Roof Height (h), whichever is smaller, but not less than either 4% of Minimum Building Dimension (L) or 3 ft.

How do I enter multiple openings?
By default you will be on the first tab, “Single Opening”, so notice the other tabs to the right (“Openings 1-10”, etc.). In short, enter up to ten openings at a time, starting with the “Openings 1-10” tab. To enter up to 20 openings, use the “1-10” AND “11-20” tabs. You can enter up to 20 openings in one submittal.

How does being a shutter make any difference?
This can be complicated to explain, so bear with me: if an opening is marked as a shutter, or if the opening width is less than one-third the opening height, the tributary area is determined by opening height squared divided by three (H^2/3); otherwise, area is determined by opening height times opening width (H*W). Checking off the “Shutter?” box forces the area to be calculated by H^2/3.

Why didn’t you receive my submission?
The most common reason is mentioned in the above section. If that is not the case, and neither the video nor the rest of the page helps, please contact us below.

Where did all my local saves go?
All data saved via the “Local Save/Load” button are reset every time the calculator is updated. This is a known limitation. (It bothers me too!)

Why can’t I print?
The official (and unofficial) story is this:

Engineering Express is glad to provide initial pre-calculations online for client and public use. We have been receiving word from building officials that printouts of unsealed work are being submitted with building permits and on occasion being approved, tying our name to a project without our consent and contract.

We continue to refine our online tools to limit this ability and notify building officials that they are not valid for use, and request that our services be hired for a professional certification of all engineering work as originally intended.

Thank you for your understanding and cooperation in this matter and please feel free to contact us to assist in your engineering needs. There is also our online store available to help for purchasing affordable pre-engineered wind pressure charts by visiting

I’m sincerely sorry about the inconvenience, and I hope you still find the calculator useful enough to use despite the lack of easy printing. Thanks for your understanding!

Known Limitations

There are certain annoyances that we cannot fix, primarily due to the program used to create the calculator. While we acknowledge their existence, there isn’t anything we can do about them at this time. We apologize for the inconvenience. Please be aware, the following list is not exhaustive; we will expand it as information is brought to our attention.

        • Double-clicking a number box does not select everything inside.
        • Submitting more than one project at a time is unsupported; the page must be refreshed between projects. You can utilize the “Local Save/Load” button to temporarily hold your data.
        • All data saved via the “Local Save/Load” button are reset every time the calculator is updated.
        • Scenarios loaded via the “Local Save/Load” button appear fine, but the fields are not really populated properly. When loading a local save, individually change each value in width, height and zone to a different value; then change them back. Having done that, the program should register the values.

Contact Us

Before contacting us, please watch the instructional video and read through this page. If your issue still has not been addressed, you can contact us via our contact form by clicking here. Please fill it out to the best of your ability, describing the issue as well as possible, and we will e-mail you back within 24 hours.

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