Tag Archives: IRC

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.

Wood I-Joists for Your Barndominium

With many barndominiums being multi-storied, or at least having lofts or mezzanines, there are several methods of structural support. These would include dimensional lumber, wood trusses and I-joists.

In our own post frame barndominium, we utilized I-joists as rafters for both side sheds. They are also floor joists for my lovely bride’s mezzanine sewing loft – a partial third floor above our master bedroom.

When I began my prefabricated metal connector plated wood truss career back in 1977, one of my first jobs was cutting webs for wood floor trusses. Then, wood floor trusses were a fairly new concept, they allowed for much longer clearspans than dimensional lumber, were consistent in size and made for very fast framing.

Floor trusses were (and are) in direct competition with I-joists. I-joists were invented in 1969 and are engineered wood products used for both floors and roofs. They have a great deal of strength in relationship to size and weight.

I-joists require correct installation – meaning a requirement for more experience and training than a dimensional lumber framed floor. Most common mistake is misplacing or improperly sizing holes in OSB (Oriented Strand Board) webs. This can compromise I-joist strength, potentially leading to structural failure. Other common installation mistakes include cutting or chiseling flanges, improperly size joist hangers, improper nailing and wrong sized nails. Rim joists much also match I-joist size as mismatches can strain joists. When an I-joist crosses a main beam, squash blocks must be installed alongside I-joists to transfer loads from I-joist to beam. Missed nails and glue setting too fast can lead to an uneven or squeaky floor. Field modification or repairs usually require manufacturer’s consultation.

I-joists need to be drilled for mechanical installations (e.g. HVAC, electrical, plumbing, etc.) leading to lost-time and effort as compared to open web floor trusses. in order to meet IRC (International Residential Code), I-joists must be covered on both sides of their full solid web with fire resistive chemicals or cladding. I-joists often do not perform well when exposed to fire or water. Thin I-joist webs can be relatively easily damaged or burned through by fire. OSB I-joist webs can be swelled by excessive moisture absorption causing web weakening. Top and bottom flanges (usually 2×4) can exhibit cupping, warping or splitting from excessive swelling due to moisture absorption.

For vibration control, both web stiffeners and blockings can be necessary to obtain desired floor stiffness.

Floor trusses have a distinct advantage for being mechanical equipment friendly. With the ability to design chase openings for ductwork through them, this is a big advantage. But let’s say there is a job site change and the truss company was not informed (never happens right?) and the ductwork must be shifted. Openings in webbing will allow for this adjustment to happen seamlessly. With this type of flexibility, who wouldn’t want floor trusses?

With I –Joists, holes you can actually cut into each joist can be pretty small. These holes also must follow certain parameters. Sometimes this is very limiting and you must stay within certain locations to place holes. Let’s not forget if you cut into a flange, a big no-no, you’re going to need a new joist.

Floor trusses can clear-span with the same floor ratings much further than any I-Joist product. This is very beneficial to frugal barndominium builders and owners out there. Let’s face it though; aren’t we all trying to be more frugal with everything we do? Who wants to put in an extra steel beam and posts or 3-4ply LVL to carry some “I’s” those extra 3’ or 4’ because their span rating is good for distance required? Those beams could add up to several hundred (even thousands) of dollars.

I-Joists may need an increased depth or decreased spacing to span very same distances, using very same design criteria. Bridging and blocking can be increased to “shore” up a floor, but this runs a risk of them being omitted.

In my mind, floor trusses are a winning answer. Are they for you?