Tag Archives: International Residential Code

Building Department Checklist 2019 Part 1

BUILDING DEPARTMENT CHECKLIST 2019 PART I

I Can Build, I Can Build!

(First published six years ago, it was more than past time to update to reflect current code requirements!)

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 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 post frame building outcome.

#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 the small investment of a firewall. 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. IBC (International Building Code) only applies to post frame buildings, not IRC (International Residential Code:

(https://www.hansenpolebuildings.com/2018/10/what-building-code-applies-to-post-frame-construction/).

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 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 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. Now 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.  Don’t assume a friend of yours who lives in your same city has your same wind speed.  The city of Tacoma, WA has six different wind speeds within city limits!

Vult and nominal design wind speed Vasd are NOT the same thing. Make certain to always get Vult values.

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

Take a few minutes to understand the 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 the 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!

 

Bookshelf Girts for Insulation

In the land where I first became acquainted with pole barn (post frame) building construction, was used a term known as commercial girts. These are actually what is more appropriately named “bookshelf girts” designed so as to create an insulation cavity which would extend 1-1/2 inches outside of the columns. The commercial girt is sized so the wall columns do not project inside of the plane of the bookshelf girts. An example would be using a 2×8 girt on 6×6 columns.

Reader Matt in Poland writes:

“Hi Mike, I didn’t come across your blog until after we purchased our pole barn package (not from Hansen) and were getting started. Our mistake, but we have learned so much from your blog.

My question is around the “illusive” commercial girts aka Bookshelf girts. When I say illusive, it is because, there are only about 2 internet postings about them, both belonging to you. We put standard 2×4 girts on the outside with Housewrap then metal. Now we are working on starting the interior and are going to go with 2×8 commercial girts inside. My question is running exterior wall things such as some plumbing, Gas lines etc. I do understand the electrical can run down the face of the post and has a 1 1/2 channel to do such, but what about those other things for rough-in.

We have taken a lot of pictures, and hope to post more information about our current build so that others can hopefully gleam information too.

Thanks Matt”

Matt’s kind words are of course much appreciated. The Hansen Pole Buildings’ “Ultimate Post Frame Building Experience™” is crafted with the idea of delivering the best value post frame building kit package to best meet with the ultimate needs of the client. In the case of Matt, it sounds as though his particular supplier may not have asked enough questions to have truly given to him the best design solution.

I will surmise Matt’s building has 6×6 columns with 2×4 “flat” girts placed on the exterior of the wall columns. As the bookshelf girts are being used to provide a surface for interior finishing only, it is possible a girt size as minimal as 2×4 could be used, holding the girt flush to the inside of the columns. Not only would this prove to be a greater cost savings, it also eliminates the transfer of heat and cold through girts which would touch both the exterior and interior finish surfaces. This type of interior commercial girt only needs to be stiff enough to resist undue deflection of the gypsum wallboard. This deflection limitation is to prevent taped joints from cracking.

As much as possible plumbing should not be run through exterior walls, especially in climates where freezing is possible during winter months.

The are some Building Code limitations as to the size of holes which can be drilled through sawn lumber, this excerpt is from the IRC (International Residential Code):

IRC R802.7.1 Sawn lumber.

“Notches in solid lumber joists, rafters and beams shall not exceed one-sixth of the depth of the member, shall not be longer than one-third of the depth of the member and shall not be located in the middle one-third of the span. Notches at the ends of the member shall not exceed one-fourth the depth of the member. The tension side of members 4 inches (102 mm) or greater in nominal thickness shall not be notched except at the ends of the members. The diameter of the holes bored or cut into members shall not exceed one-third the depth of the member. Holes shall not be closer than 2 inches (51mm) to the top or bottom of the member, or to any other hole located in the member. Where the member is also notched, the hole shall not be closer than 2 inches (51 mm) to the notch.”

This would allow for a hole of up to 1-13/16 inches to be bored through a 6×6 column, without adversely affecting the strength of the column.

Planning on climate controlling your new post frame building? Discuss the options with your Hansen Pole Buildings’ Designer to arrive at design decisions which will best meet your needs today, as well as in the future.

Pole Barn Decks

A Decked Out Lesson

I keep telling people after over forty years in the construction industry I am still learning new things each and every day.

Today being no exception, I found out things I did not know about decks.

I’ve spent most of my building career immersed in post frame buildings, which (until the past few years) were rarely used as residences. And, even when they were designed to be dwellings, rarely were they designed with attached decks.

Then along comes the rise of the barndominium.  Read more about barndominiums here: https://www.hansenpolebuildings.com/2016/04/the-rise-of-the-barndominium/

My lovely bride and I happen to live in a post frame building. It has no decks at this point in time. However, the idea has been bandied about in regards to perhaps someday having one which would be located off our living room.

In the 1980’s I had a business located on Highway 99E in Clackamas County, Oregon. With this personal history, it was not surprising to me to find myself being schooled by this county’s Building Department. This happens to be the very same county which was responsible for the creation of “Arborvitae Green” tree paint (the somewhat comical story is available to peruse here: https://www.hansenpolebuildings.com/2015/06/painting-steel-siding/).

Chapter 16 of the 2014 Oregon Structural Specialty Code gives us this:

“1604.8.3 Decks. Where supported by attachment to an exterior wall, decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads as applicable. Such attachment shall not be accomplished by the use of toenails or nails subject to withdrawal. Where positive connection to the primary building structure cannot be verified during inspection, decks shall be self-supporting.”

The International Residential Code (IRC) does not apply to post frame buildings. But because it is a prescriptive code, and does not even mention post frame, it does address the deck to building connection.

The section from the International Residential Code (R502.2.2) says decks have to be designed for both vertical and lateral loads. This part has been on the books for years and is meant to keep the deck from pulling away from the house. But the 2009 IRC does have a new provision which gets specific about what’s required to support a lateral load.

The new code section (R502.2.2.3) states “hold-down tension devices” be installed in at least two locations per deck. Whether you are attaching a deck 3 or 30 feet long, it is required to use the hold-down tension devices in two locations.

Each hold-down device must “have an allowable stress capacity of not less than 1500 lb.” The hold-down devices might be tough to find, though, because right now, only Simpson’s DTT2Z Deck Tension Tie (www.strongtie.com) meets the design-load requirements.

All non-cantilevered Hansen Pole Buildings’ deck designs now include the above mentioned deck tension ties.

Oh, by the way, the plans reviewer did happen to note (in regards to our engineer’s deck attachment), “I’m sure his calculations are correct”!

Proposed Building Code Change to Add to Construction Costs

During each 3-year-cycle of the International Building Code (IBC) and International Residential Code (IRC), there exists an opportunity to propose modifications and improve the codes to recognize new and innovative construction.  During the final two weeks in April, the code proposal hearings were held in Louisville, Kentucky where several hundred proposals were discussed and considered for inclusion in the code.

large-span-trusses-150x150While post-frame construction is typically used in agricultural applications which are often (and in my humble opinion sadly) considered exempt from code compliance, more and more post-frame construction is either residential housing (IRC) or commercial (IBC) in nature.  In these cases, changes which impact the code may have an effect on how post-frame buildings are constructed.

Eight proposals were identified by NFBA (National Frame Building Association) staff as having a potential impact on post-frame construction.  While the majority of these proposals were defeated, the following action should be noted:

S138-16: Submitted by the Structural Engineers Association, this proposal was approved and will require special inspection for wood trusses with a clear span of 60 feet or greater or an overall height of 60 inches or greater.  While the clear span is not a major issue, the 60 inch height may impact a number of projects creating new cost/scheduling issues.  This change is scheduled to be included in the 2018 IBC.

Having spent my entire adult life installing, designing, selling, building, delivering and purchasing wood trusses, it would seem ludicrous to require a special inspection for wood trusses with an overall height of 60 inches or greater. This would add an extra layer of inspection to nearly every building (not only post frame) project, with seemingly no apparent rationale other than the employment of a large number of people to perform these inspections (most likely the same structural engineers who made this proposal).

Trusses spanning 60 feet or more, are already required to have special inspections, under the IBC: https://www.hansenpolebuildings.com/2013/12/wide-span-trusses/.

What can you do? Contact your local Building Official today and ask them to vote to repeal this costly measure which does little or nothing to improve the safety of buildings.

Prefabricated Roof Trusses Part One

Prefabricated Roof Trusses – They can Make You or Break You

This article (written by yours truly) was published in the May 2016 Rural Builder magazine (https://media2.fwpublications.com.s3.amazonaws.com/CNM/RB_20160501e.pdf and begins on Page 26). Although the article is written towards post frame (pole) building contractors, it gives a perspective as to the challenges of ordering something as apparently simple as a set of prefabricated roof trusses:

I worked for, managed or owned roof truss manufacturing facilities from 1977 until 1999 – so we only ever had to operate under the pre-International Building Codes, which made our lives easy. Regardless of roof slope, exposure to wind, roofing material, whether a building was heated or unheated, the top chord live load (or roof snow load) was the same within any localized geographic region, with the exception of differences in snow load caused primarily by elevation changes.

When a client brought in a set of plans, we took on the responsibility to insure the quantity of trusses, roof and ceiling profiles, etc., were correct. We looked upon ourselves as being the experts – rather than the builder or building owner who was purchasing the trusses.

Walk in the door of a truss company today with a set of plans for a truss quote and the expectation is the purchaser has to be “in the know”, which I personally find counter intuitive, but it is the current reality.

As a broad generalization, today’s truss manufacturers are looking out for one entity, and it is not the person writing the check to pay for their product.

I am going to share some secrets which should both increase your bottom line as well as allow you to sleep soundly at night.

First – do not assume the truss company is going to do it right. It is better to take the more realistic position of, they will do it wrong. Wrong can result in an increase in the probability of a catastrophic failure, having to pay more than one should, or both.

Secondly – if you are shopping various vendors, the best price on the truss order might not be the best buy for your building.

A little sharing into how to make sure the trusses you order actually meet the required load conditions.

I am going to put in a plug here for Registered Design Professionals or RDPs. If you are constructing post frame buildings, or providing post frame building kit packages, and are not using originally RDP sealed plans, which are specific to the address where the building is being erected, you are seeing the light at the end of the tunnel and the light is a speeding train.

Maybe you have built or provided hundreds or even thousands of buildings and never had a failure. Trust me, the failure is going to come, and may have nothing to do with how the building was designed, but if an RDP did not design it you are placing yourself and your business at a tremendous risk.

On to important stuff, the Building Codes.

The IRC (International Residential Code) is a prescriptive code for stick frame buildings within limited parameters of snow and wind loads. It does not address post frame construction therefore all post frame buildings should be designed using the IBC (International Building Code).

The International Building Code (IBC) identifies the appropriate Ground Snow Load (Pg) to use on a building based upon its location. When jurisdictions adopt the IBC, they should also be designating the Pg value or values within their area of coverage. Some Building Officials are still rooted in the 1900’s and (contrary to the current Code) designate a Roof Snow Load, which often defies the Laws of Physics.

A case in point, not too many years ago, we provided the post frame building kit package for the Nature Center at the Cheyenne Mountain Zoo in Colorado Springs, Colorado. The Building Department gave the ground snow load as 27 psf (pounds per square foot), yet wanted 40 psf as the roof snow load. When our engineer called the Building Department to discuss this, the explanation given was, “The snow is just different here!”

Hmmm, ‘the snow is just different here’. Sounds pretty scientific. How about I give you some guidance as to what to really pay attention to, so your building is not only designed correctly to stay up but also how to save you some money. Sound good? Well, come back tomorrow to read Part II and get those answers… and a whole lot more.