i am going to build a sip over icf basement in boone nc--at 4300 ft altitude i must construct to 130 mph loads---can i build without a timberframe and meet this requirement---where can i get more info for wind loads and strapping---i want to use sip for roof, walls, and floor---i want high pitch roof but as i arthritis, i am building a single story home, but will have walk out basement--thanks ahead for any help

Van;

We build to 130 mph or greater with no additional frame work , feel free to send a direct email to [email protected] for additional information

I have read your post regarding wind loads. As a Texas Department of Insurance certified hurricane zone engineer, this is an area of my practice I work with almost every day.

In order to determine the windloads on any structure several items of information are required:

1. Design wind speed (130 mph as you stated)
2. Dimensions of the structure and the structures orientation on the site (North, South, etc.)
3. Type of roof (gable, hip, mansard, etc.)
4. Geographic location

Now we have sufficient information that we can began to populate the calculations to determine wind load (pressure) on the various areas of the structure. Wind load calculations are done using ASCE-7.05 Minimum Wind Load Design Standards. This is a tedious family of calculations and should only be attempted by trained professionals. Results, even correct results, must be interpreted by a professional.

Now all this work has only told us what the wind load pressures are on the structure, typically there will be both positive and negative pressures on different areas of the structure at the same time, depending on the wind direction and dimensions of the structure. Typically one portion of the structure will be in positive pressure and another area in negative pressure (suction), which can remove the dead load that is often used to calculate the Main Wind Force Resisting System (MWFRS). As the wind passes over and around your structure will be be speeding up and slowing down, thus creating positive and negative pressures in different locations at the same time.

But we still no nothing of how your structure will respond to the pressures. The determine how a specific structure will respond to a wind load, we must have a complete set of plans and perform an analysis the various pressure relationships on the materials through out the structure. Simply knowing the force values of various fasteners will not tell us any thing about what forces are being applied and in what locations. For example, a Simpson strong tie of some type in the wrong position will do us no good; however, the same fastener in the right position may add several percentage points to the amount of force a wooden member or joint may support. Many times builders rely upon printed advertisements and manufactures installation guides for where and how often a fastener should be applied. In reality, no one knows with out performing the wind load and MWFRS analysis that I previously described.

I would like to urge you to contact a local engineer who is familiar with your local building codes and SIPs to perform this analysis for you. The cost of competent engineering work seems high - until your roof blows off. If any one would like to discuss this issue further please contact me off list at any of my contact information listed below.

Good luck,

Matt


Matt B. Phelps, P.E., R.S.
SIPs Engineering & Testing, LLC
201 CR 138
Hutto, Texas 78634
512-670-9400
[email protected]

Mr. Phelps,

As a retired educator, I commend you.  Your explanation was succinct and yet easy to follow.  I agree with you wholeheartly about seeking professional advice regarding wind loading.

Matt and Alton;

I also agree, we do not rely solely on the manufacturer's stated wind load charts. 
 As needed we  have the entire structure engineered by third party engineers (licensed in the state where the sips to be used) to evaluate spans, connection details, design pressures and geographic location.
In some cases we have provided the actual calculations for code enforcement if required.

Van,

I think you have received some very good advice, retain a structural engineer. The few dollars you will spend will save you headaches down the road. Our Pre-Insulated Steel Framing system is a Miami-Dade Hurricane approved system. We have done simulated lab wind test on our panels and they stood up to 225 mph conditions. Yet… they are lightweight and easy to work with. No heavy equipment required.

David, Kwik-Build Panels