Tag Archives: Residential Building Code

Building Code, “Barndos”, and Barn Doors

This week the Pole Barn Guru answers reader questions about which building code applies to a residential “pole barn,” a “Barndo” for Betty, and stall doors for a horse barn.

DEAR POLE BARN GURU: Planning to build in Fremont County, CO. This will be a 2 bedroom residential cabin at 9400 ft. Which building code will apply, Single Family Residential or Pole Barn? JEFF in ATLANTA

DEAR JEFF: There is no “Pole Barn Code”. For one and two family dwellings (R-3) IRC (International Residential Code) will dictate, however it does default to IBC (International Building Code) for structural aspects.

In “Effective Use of the International Residential Code”:

Paragraph 4:

“It is important to understand that the IRC contains coverage for what is conventional and common in residential construction practice. While the IRC will provide all of the needed coverage for most residential construction, it might not address construction practices and systems that are atypical or rarely encountered in the industry.”

IRC R301.1.3 Engineered design.

“When a building of otherwise conventional construction contains structural elements exceeding the limits of Section R301 or otherwise not conforming to this code, these elements shall be designed in accordance with accepted engineering practice. The extent of such design need only demonstrate compliance of nonconventional elements with other applicable provisions and shall be compatible with the performance of the conventional framed system. Engineered design in accordance with the International Building Code is permitted for all buildings and structures, and parts thereof, included in the scope of this code.”

 

DEAR POLE BARN GURU: How much would it cost for a barndo like the one in the attached picture? BETTY in RADCLIFF

DEAR BETTY: To get an exact price on this, or any, fully engineered post frame barndominium, please call 1.866.200.9657 and speak with a Hansen Pole Buildings’ Designer. Your Building Designer will ask you questions about your building footprint, ceiling heights, building slab-on-grade or over a crawl space or basement, number and size of windows and doors, how you will be insulated, etc. You can easily have changes made to any or all features and dimensions until you arrive at an ideal design solution meeting your family’s wants and needs.

If you do not yet have a floor plan, one can be crafted for you http://www.hansenpolebuildings.com/post-frame-floor-plans/?fbclid=IwAR2ta5IFSxrltv5eAyBVmg-JUsoPfy9hbWtP86svOTPfG1q5pGmfhA7yd5Q

 

DEAR POLE BARN GURU: I have a metal barn already with two door openings. I am in need of doors for these openings. It is meant a for stall doors for a horse barn. You can kind of see the barn door openings in the photo behind my son. Do you sell just the doors? BRENDA in BERTHOUD

 

DEAR BRENDA: Thank you very much for your interest. Due to challenges of shipping without damage we only provide doors with our complete post frame building kit packages.

Building Department Checklist Part I

BUILDING DEPARTMENT CHECKLIST 2020 PART I

I Can Build, I Can Build!

Whoa there Nellie…..before getting all carried away, there are 14 essential questions to have on your Building Department Checklist, in order to ensure structural portions of your new building process goes off without a hitch.  I will cover the first seven today, finishing up tomorrow, so you have a chance to take notes, start your own home file folder of “what to do before I build”.  Careful preparation will be key to having a successful building outcome (whether post frame or some other structural building system).

Provide answers to these questions to your potential building providers!

IMPORTANT SIDE NOTE: Building Departments’ required snow and wind loads are absolute minimums in an attempt to prevent loss of life during extreme events. They are not established to prevent your building from being destroyed. Consider asking your providers for added investment required to increase wind and/or snow loads beyond these minimums.

#1 What are required setbacks from streets, property lines, existing structures, septic systems, etc.?

Seemingly every jurisdiction has its own set of rules when it comes to setbacks. Want to build closer to a property line or existing structure than distance given? Ask about firewalls. If your building includes a firewall, you can often build closer to a property line. Creating an unusable space between your new building and a property line isn’t very practical. Being able to minimize this space could easily offset a small firewall investment. As far as my experience, you cannot dump weather (rain or snow) off a roof onto any neighbor’s lot, or into an alleyway – so keep those factors in mind.

#2 What Building Code will be applicable to this building?

Code is Code, right? Except when it has a “residential” and also has a “building” version and they do not entirely agree with each other.

Also, every three years Building Codes get a rewrite. One might not think there should be many changes. Surprise! With new research even things seemingly as simple as how snow loads are applied to roofs…changes. Obviously important to know what Code version (e.g. 2012, 2015, 2018, 2021) will be used.

 

#3 If building will be in snow country, what is GROUND snow load (abbreviated as Pg)?

Make sure you are clear in asking this question specific to “ground”. When you get to #4, you will see why.  Too many times we’ve had clients who asked their building official what their “snow load” will be, and B.O. (Building Official) replied using whichever value they are used to quoting.  Lost in communication was being specific about “ground” or “roof” snow load.

As well, what snow exposure factor (Ce) applies where a building will be located? Put simply, will the roof be fully exposed to wind from all directions, partially exposed to wind, or sheltered by being located tight in among conifer trees qualifying as obstructions? Right now will be a good time to stand at your proposed building site and take pictures in all four directions, and then getting your B.O. to give their determination of snow exposure factor, based upon these photos.

#4 What is Flat Roof Snow Load (Pf)?

Since 2000, Building Codes are written with flat roof snow load being calculated from ground snow load. Design snow load has become quite a science, taking into account a myriad of variables to arrive with a specific roof load for any given set of circumstances.

Unfortunately, some Building Departments have yet to come to grips with this, so they mandate use of a specified flat roof snow load, ignoring laws of physics.

Make certain to clearly understand information provided by your Building Department in regards to snow loads. Failure to do so could result in an expensive lesson.

#5 What is “Ultimate Design” or Vult wind speed in miles per hour?

Lowest possible Vult wind speed (100 miles per hour) only applies in three possible states – California, Oregon and Washington for Risk Category I structures. Everywhere else has a minimum of 105 mph.  Highest United States requirement of 200 mph for Risk Category III and IV buildings comes along portions of Florida’s coastline (although there are scattered areas nationally defined as “Special Wind Regions).  Don’t assume a friend of yours who lives in your same city has your same wind speed.  City of Tacoma, WA has six different wind speeds within city limits!

Vult and nominal design wind speed (Vasd) are different and an errant choice could result in significant under design (or failure). Make certain to always get Vult values.

#6 What is wind exposure (B, C or D)?

Please Take a few minutes to understand their differences:

(https://www.hansenpolebuildings.com/2012/03/wind-exposure-confusion/).

A Building Department can add hundreds, or even thousands, of dollars to your project cost, by trying to mandate an excessive wind exposure.  Once again, a good place for photographs in all four directions from your building site being shared with your Building Department.  Some jurisdictions “assume” worst case scenarios.  Meaning, your property could very well have all four sides protected and easily “fit” category B wind exposure requirements.  However, your jurisdiction may have their own requirement for every site in their jurisdiction to be wind exposure C, no matter what.  It’s their call.

#7 Are “wind rated” overhead doors required?

Usually this requirements enforcement occurs in hurricane regions. My personal opinion – if buying an overhead door, invest a few extra dollars to get one rated for design wind speeds where your building will be constructed. Truly a “better safe, than sorry” type situation.

I’ve covered seven most important questions for your Building Department Checklist, and they really weren’t so difficult, were they?  Come back tomorrow to find out the last seven!

International Residential Code and Tension Ties

International Residential Code and Tension Ties

Reader DENNIS in TRAVERSE CITY writes:

“ICC R602.10 is written to work with continuous foundations and vertical studs, not posts in holes and horizontal girts.
How does a person translate bracing into post-frame language?
An answer addressing tension ties would be helpful.”

From the 2015 International Residential Code (IRC):

R602.10 Wall bracing.

Buildings shall be braced in accordance with this section or, when applicable, Section R602.12. Where a building, or portion thereof, does not comply with one or more of the bracing requirements in this section, those portions shall be designed and constructed in accordance with Section R301.1.

R602.12 Simplified wall bracing.

Buildings meeting all of the conditions listed below shall be permitted to be braced in accordance with this section as an alternate to the requirements of Section R602.10. The entire building shall be braced in accordance with this section; the use of other bracing provisions of Section R602.10, except as specified herein, shall not be permitted.

  1. There shall not be more than three stories above the top of a concrete or masonry foundation or basement wall. Permanent wood foundations shall not be permitted.
  2. Floors shall not cantilever more than 24 inches beyond the foundation or bearing wall below.
  3. Wall height shall not be greater than 10 feet.
  4. The building shall have a roof eave-to-ridge height of 15 feet or less.
  5. Exterior walls shall have gypsum board with a minimum thickness of ½ inch installed on the interior side fastened in accordance with Table R702.3.5.
  6. The structure shall be located where the ultimate design wind speed is less than or equal to 130 mph and the exposure category is B or C.
  7. The structure shall be located in Seismic Design Category A, B or C for detached one- and two-family dwellings or Seismic Category A or B for townhouses.
  8. Cripple walls shall not be permitted in three-story buildings.

R301.1 Application.

Buildings and structures, and parts thereof, shall be constructed to safely support all loads, including dead loads, live loads, roof loads, flood loads, snow loads, wind loads and seismic loads as prescribed by this code. The construction of buildings and structures in accordance with the provisions of this code shall result in a system that provides a complete load path that meets the requirements for the transfer of loads from their point of origin through the load-resisting elements to the foundation. Buildings and structures constructed as prescribed by this code are deemed to comply with the requirements of this section.

Please keep in mind, the IRC is a prescriptive code – it calls out the approved methods to put a stick framed building together, within the prescribed load parameters. Post frame (pole) buildings are NOT covered by the IRC, other than:

R301.1.3 Engineered design.

Where a building of otherwise conventional construction contains structural elements exceeding the limits if Section R301 or otherwise not conforming to this code, these elements shall be designed in accordance with accepted engineering practice. The extent of such design need only demonstrate compliance of nonconventional elements with other applicable provisions and shall be compatible with the performance of the conventional framed system. Engineering design in accordance with the International Building Code is permitted for buildings and structures and parts thereof, included in the scope of this code.

Accepted engineering practice and in accordance with the International Building Code  would lead your RDP (Registered Design Professional – Architect or Engineer) to utilize the NFBA (National Frame Building Association) Post-Frame Building Design Manual Second Edition.

While it is possible a design utilizing tension ties could be done, it is probably far more practical to utilize the strength and stiffness of properly fastened steel panels to transfer shear loads from the roof through the endwalls to the ground.