Archive

Posts Tagged ‘Building Codes’

2B or not IIB

October 15th, 2012

roman_numerals_2smWhat’s up with Roman Numerals in the International Building Code? Types of Construction (one through five) have been in Roman Numerals since the inception of the International Codes in 2000.  I have to ask…..Why? Is this their attempt to make the Code truly international?  Well if you have ever been to Rome, their building methods differ greatly from ours.  And although they use the metric system of weights and measure, they use regular numbers for those weights and measures.

Try composing a letter on your computer and talk about IB or IIIB construction. See what I mean, there is no top or bottom horizontal line on the I’s.  Is that 3 small “L” construction?

I know the Uniform Building Code used Roman numerals.  Did the International Conference of Building Officials negotiate away 4 hr exterior bearing walls just so they could keep the Roman Numerals?

Typical of the computer age, I Googled Roman Numerals to see what I could find on the subject. On the Math Forum site I found The Dr. Math Archives which stated three reasons why we use Roman Numerals:

roman soldier

  • to make writing look fancy (on clocks and official documents),
  • to make writing look old, and
  • to avoid confusion with ordinary numbers (in outlines and the introductions of books.)

Maybe they want you to think Types of Construction dates back to Hammurabi.  It could be they want it to look fancy. (I know I always get excited when talking about Types of Construction.)

My personal opinion is they should have followed through and made the code sections in Roman.  1008.1.8.6 Delayed Egress locks would be MVIII.I.VII.VI (I think).  This could be a new stimulus plan for the printing industry.

We do see Roman Numerals in some common things in America.  The Super Bowl for instance uses Roman Numerals.  I must say though I’m not a sports follower.  I can’t seem to make sense of paying a bunch of guys 100 times what a schoolteacher makes to run around a field with a ball.  Movies always use Roman Numerals at the beginning to show what year the movie was made, but I’m sure most of us need to check a movie guide to actually figure out what year they were made.

Finally, like the disclaimer I use for my code seminars, I use Arabic numbers when describing types of construction.  And I’m not even an Arab.

Editors Note:  When this article was transfered from Microsoft Word to the Web Page, the horizontal tops and bottoms were added to the I’s automatically.

Uncategorized

Construction Codes Explained

February 21st, 2010

With the Advent of the International Family of Codes, we have come closer than ever to having a uniform building code throughout the United States.  The International family of Codes came about when the three model code organizations Boca, ICCBO, SBC got together and worked towards developing a single building code.

A Little History

Hammurabi recieved a copy of the code from his Law Department

Hammurabi recieved a copy of the code from his Law Department

No story about codes would be complete if we didn’t talk about Hammurabi.  King of the Babylonian Empire, Hammurabi created the first known building code in 2200 B.C..  It was a little light on technical information, no span tables or egress requirements.  It simply stated that if a builder built a crappy house and it collapsed, whatever happened to the occupants would happen to the Builder.  If the homeowner’s son lost his legs in the collapse, then the builder’s son would have to have his legs removed.

The first codes in the U.S. were the results of massive fires in some of our larger cities. Chicago created a building code in 1875 after insurers threatened to cancel insurance for properties in that city. In 1915 Building Officials Conference of America (BOCA) was founded. They published the BOCA National Building Code.  This was used primarily in the east and Midwest.  In 1922 The Pacific Coast Building Code Conference (later the International Conference of Building Officials-ICBO) adopted the Uniform Building Code.  Finally, in 1940, the Southern Building Code Congress International (SBCCI) published the Standard Building Code. These were the three model codes that were used in the U.S. Today they are known as the legacy model code organizations.  In 1972 the Council of American Building Officials is formed and they produce the One and Two Family Dwelling Code.
In 1994 the three legacy codes created the International Code Council to develop a single set of model construction codes, publishing their first, The International Plumbing Code, in 1995.
One of the first orders of business for the three codes was to reorganize their codes to a single format.   This not only enabled the writers of the new International Codes to compare requirements of each code when creating the new code, it assisted users of the legacy codes to locate requirements in the new code easier.  An example is in the mid 90’s; all three codes’ Chapter on egress was changed to chapter 10.  When the International Code was published, users could easily find subjects although most found major changes to the subject matter.

What is a Code?

Building codes are regulations, when adopted by a municipality becomes law. Previously, most municipalities or states adopted one of the four model codes with amendments specific to their locale.
The purpose of building codes is to protect health, safety and welfare of the public by providing standards in construction.  I must stress that codes are minimum standards only.  The most important goal of codes is the protection of human life.  Property protection is also a concern of the code although life-safety always overrides property protection.  An example of this is slide bolts not being allowed on exit doors.  During the many inspections I’ve done of small commercial buildings, I have found rear exit doors secured with numerous “unapproved” locking devices.  I am told (by the owner) these are necessary to secure against break-ins. The code maintains life-safety over property protection and does not allow these locks. They must be removed.

Types of Codes

There are two types of codes-specification codes and performance codes. A specification code lists exactly what can be used.  For example Section 502.7.1 of the Residential Code requires Joist bridging to be …..”solid blocking, diagonal bridging, or a continuous 1-inch-by-3-inch strip nailed…..”  A performance code states a purpose that is intended and allows the designer to select the method of accomplishing this purpose. An example would be R801.2 “…..Ceiling construction shall be capable of accommodating all loads imposed…..”  The International Codes contain both types of codes.

Changes in the Code

The ICC publishes an updated set of codes every three years.  In the margin of the text you will see the occasional dark vertical line.  This means there has been a technical change in the code from the previous edition.  A small arrow indicates where an item has been deleted.  The State of Michigan, where I reside, makes state amendments to the ICC Codes.  The code is then published as The Michigan Building (Mechanical, plumbing etc.) Code.  In addition to the dark vertical lines and arrows, they use double vertical lines to indicate state changes to the code and an asterisk to denote International Code sections that were not adopted. While explaining how these changes are made to a code merits a whole other article, it is important to note that anyone can submit a code change, and hearings open to the public are held to discuss both sides of code changes.  Final say as to adopt or deny a change is left up to the “regulators”, those who enforce the code.

IBC vs. IRC

The scope of the International Residential Code and The International Building code is clearly defined.  Section 101.2 of the IRC defines it’s scope as construction, alteration……etc. of “detached, one- and two-family dwellings and townhouses not more than three stories above grade in height with a separate means of egress…”  The one and two family part is easy.  For townhouses we must look at its definition in chapter 2.  “….each unit extends from foundation to roof and with open spaces on at least two sides”.  Now we easily understand townhouses (remember separate means of egress and no more than 3 stories).  Let’s say we have a condominium complex where one building has units in the middle that meet the townhouse parameters.  On the ends of these units we have “stacked ranches”-different units on top of each other.  Even though we are providing a 2-hr horizontal separation (required 2-hr separation for townhouses in section R317.2), we are unable to use the IRC to build this building.  It must be reviewed under the IBC (bringing fire suppression into the picture).
Maybe not!! R317.2 considers each townhouse to be a separate building.  Could you secure permits for each townhouse and review it under the IRC and secure permits for the stacked ranches using the IBC for review.  I believe you can.  This is where the design professional should solicit the opinion of the local official in the predesign stages.

Referenced Standards

An interesting note on the IRC-it is an all inclusive document.  That is it not only contains the building requirements but also mechanical, electrical and plumbing codes.  Just read the 500 plus pages of the IRC and you’ll know all the requirements for building these dwellings.  Not really.  In chapter 43 of the IRC and in Ch 35 of the IBC we have a number of pages of “Referenced Standards”.  These standards become part of the code, sometimes partially or sometimes in their entirety, depending on how they are referenced.
An example of this would be “The Wood Frame Construction Manual for One-and Two-Family Dwellings” from American Forest and Paper Association (AF&PA).  This is reference in section R301.2.1.1 as one of the 5 methods of design for high wind/hurricane prone regions.  This document now becomes part of the code for these regions.

Free Advice

First and foremost, you should know which code the jurisdiction you are working in enforces.  You should have a copy of it also.  As far as understanding it, attending educational seminars is a great start but on any project I recommend you make contact with your local authority in the planning stages.  Contrary to common belief, most inspectors do not take pleasure in making you tear down what you have built.  Don’t wait until you’ve roughed-in 12 floors of a residential loft development before making contact with your inspector.

Articles

Access-Controlled Egress Doors

December 22nd, 2009

Nowadays security is a top priority for commercial properties due to terrorism, corporate espionage and threats to personal safety.  In the design phase of new buildings or renovations to tenant spaces, designers must take care that security measures meet the requirements of the building code.  I will talk specifically about Access-controlled egress doors (section 1008.1.3.4 of IBC 2006).

This section talks not only about entrance doors to a building, but any doors which are part of a means of egress.   In other words, if one has to go through a door to get out of the building, the following requirements must be met:

1)    A sensor must be installed on the egress side which detects an occupant approaching.  The door(s) must open either by a signal from or loss of power to the sensor.

2)    Loss of power to the access control system unlocks the door.

3)    Manual unlocking device must be placed on the egress side of the door.

4)    Activation of the building fire alarm (if provided) system shall unlock doors.

5)    Activation of building sprinkler or fire detection system (if provided) shall unlock doors.

6)    Entrance doors (not to be confused with entrance doors in a means of egress) in Groups A, B, E or M shall not be secured from the egress side when the building is opened to the general public.

We will look at three scenarios where security requires controlled access to a space.  First, we will look at the CEO’s office (figure 1). Her office is on the 32nd floor of a high rise building.  Security concerns require entry to the reception area leading to her office is gained only by keycard access. Placing the sensor and manual unlocking device on the reception side of the doors will not allow access to the office by an unwanted occupant(unless they know how to set off the fire alarm/ detection system, sprinkler system or cut power to that part of the building).  This scenario can easily comply with code requirements.

Figure 1

Figure 1

In the next two scenarios, meeting code requirements will defeat the purpose of providing the access control.  First we will look at locked doors in an elevator lobby (figure 2). In a multi-tenant high-rise, it is normal for tenants to restrict entry to their floor.  Locking stair doors from the stair side is allowed under certain conditions.  The only other access to the floor would be from the elevators.  If access control is installed at the elevator lobby, 2 of the code requirements would defeat the purpose of the locking devise.  Since the stairs (means of egress) are on the other side of the door (the tenant space), the sensor and the manual unlocking device have to be located in the elevator lobby.  The person you are trying to keep out just has to walk up to the sensor or manual unlocking device to get in.

Figure 2

Figure 2

Finally, we’ll look at a floor of a high rise building which has two different tenants (figure 3).  In this design, each tenant space has one stairway.  Two means of egress are required for each space so installing locking devices on doors leading to the other stair would require the sensor and manual unlocking device on the egress side,  again defeating the purpose of the locks altogether.

Figure 3

Figure 3

The solution?  Forethought.  By the time this issue is brought to the forefront, rerouting egress paths is impossible. A lot of the time, the controlled entry devices are installed by the owners without the knowledge of the general contractor and sometimes after final inspections.  I was once involved in a project that received a variance from the local authority.  They were not required to install the sensor or manual unlocking device (both of which would have defeated the security measure).  They did have a non-required sprinkler system in the building.  They didn’t, however, use the exception for pull station requirements (because of the sprinkler system) and placed pull stations throughout the building accessible to the public.

NOTE: Section 1008.1.4.4 of the 2009 IBC, access-controlled egress doors remains the same as 2006 except Group I-2 is added to groups A, B, E, M, R-1 and R-2 where access control is allowed.

Articles

Shafts

October 2nd, 2009

I recently made a visit to a new, 3 story retail development. The purpose was to inspect two 2-hr fire-resistance rated duct shafts.  The shafts were continuous from the rooftop HVAC unit to the first floor, with openings onto all floors. Two previous inspections had failed for improper support of the shaft wall and improper framing for the fire/smoke dampers.

The building was reviewed as 2B construction and therefore the floors and columns required no rating. As the shaft walls (typical core board/metal stud construction) were built on the concrete floor, it didn’t meet the requirements for support.

Shaft walls must meet the requirements of a fire barrier and Section 706.5 of The 2006 International Building Code states “The supporting construction for fire barrier walls shall be protected to afford the required fire-resistance rating of the fire barrier supported…”  This means the horizontal and vertical steel which supports the concrete floor adjacent to the shaft must maintain the 2-hr rating. In this case, the columns and beams responsible for supporting the shaft wall were protected with spray on fireproofing.

elevation

Framing requirements for the fire/smoke dampers are specified by the damper manufacturer.  These may include doubling vertical framing members for larger dampers, specific methods for corner returns on the horizontal members and minimum and maximum clearances between the framing and the damper.

The installation of these shafts exceeded the minimum code requirements in two ways.  First, the shafts connected less than four stories.  IBC 2006 section 707.4 only requires a 1-hr rating.  Second, the shafts were not required at all.  Section 716.6.3 Nonfire-resistance-rated floor assemblies (remember Type 2B construction=no floor rating) only requires a fire damper installed at the floor line when connecting not more than three stories.

Now the design professional, building owner or building insurer might have required this higher level of protection (remember the Code is only a minimum requirement). The cost of shaft wall construction, additional protection of structural steel and fire/smoke dampers (including the electronics for the activation of the smoke dampers) should have been considered.

PLAN VIEW

PLAN VIEW

It Pays To Know $$$

Separation between dwelling units and non-residential occupancies

September 10th, 2009

As you may remember, in the 2006 edition of The IBC section 419 was a new addition which provided scoping requirements for horizontal and vertical separations between dwelling or sleeping units in I-1, R-1, R-2 and R-3 Occupancy classifications.  The one-hour separation requirement had always been in Chapter 7 of the IBC but now there was a directive to send you to Chapter 7 when checking on special requirements for the occupancies in question.

Now in 2009, the IBC has added that the same “between-unit” requirements be met between these occupancies and others.  Why is this important?  In some instances, the previous versions of the code would allow you to have no fire-resistance-rated separation between say a manager’s office and the apartment next to it.  Let me give you an example:

7000 sq ft, Type 3B Construction

7000 sq ft, Type 3B Construction PLAN VIEW

Let’s take a 7000 sf building, with 5000 sf of 1st floor area and 2000 sf on the second floor.  The second floor contains 2 apartments.  In 2006, section 419 sends you to 719(fire partitions) and 711(horizontal assemblies).  Both of these sections talk about ratings for walls or floors separating dwelling units (or sleeping units).  It did not require any separation between dwelling units and other occupancies other than the requirements for separated occupancies in Table 508.3. Now, we’ll say we are going to put in a BBQ restaurant in our building with solid fuel grilles.  The Code allows us to have non-separated occupancies if the building does not exceed the most restrictive building area and height limitations (from Table 503) for the occupancies in question.  We have an R-2 which is allowed to be 16,000 sf and 4 stories and an A2, which is allowed to be 9500 sf and 2 stories.  Since the A2 is the most restrictive and our building has not exceeded this, no separation is required under 2006 IBC.

2006 IBC only required 1-hr separation between dwg units

ELEVATION

We could have an open ceiling with open floor joist between the restaurant and the apartments. (The requirements for the Sound Transmission Class requirements, oddly enough, have always required a “sound” separation (STC 50) between dwelling units and “public or other service areas”.)

All this changes in 2009.  Language has been added to require the 1-hr rating between dwelling or sleeping units and “other occupancies contiguous to them in the same building”. Now a minimum 1-hr rated floor ceiling assembly would be required between the restaurant and the apartments.

2009 IBC now requires at least a 1-hr horizontal separation between the lower level bar and the second floor apartments

2009 IBC now requires at least a 1-hr horizontal separation between the lower level bar and the second floor apartments

As before, in Types 2B, 3B and 5B, these separations can be reduced to ½ hr in buildings equipped with an NFPA 13 sprinkler system. (Has anybody figured out a ½ hour wall yet?)

Frank Bayer

New in 2009 , ,

Exit Doors Must Open Out

August 27th, 2009

All exits doors must open out (in the direction of egress).

We all know that.   We’ve either seen a television show or read a magazine article about the deadly fire at The Iroquois Theatre in Chicago back in 1903.  We’ve been told that one of the causes of the high death count (602 people, 575 which perished within the first 20 minutes) was the exit doors opened inward and in the panic, people were trampled at the doors, blocking the exits.  It was said that bodies were piled 7 ft high in front of the doors.

Well exit doors do not have to always open out.  The International Building Code allows an exit door to open inward if the occupant load is less than 50 persons.  As always, the occupant load is determined by calculation using table 1004.1.1.  (Since 2006, the IBC does allow the Building Official to approve a lesser load than those determined by calculation.)

This rule is especially useful in cases where a small commercial space is directly on the sidewalk.  The IBC does not allow doors or windows to “open or project into the public right-of-way”.

Door opens onto large sidewalk.  Is this OK?

Door opens onto large sidewalk. Is this OK?

Note: While researching this article I wanted to define “public right-of way”.  Is it municipal property used for a sidewalk, street or alley?  Is it a sidewalk in front of a strip mall (private property)?  Is there a minimum width of a sidewalk?  I could not find a definition in the IBC even though it contains a chapter on encroachments into the public right-of-way.  Webster’s Dictionary also does not contain a definition.  I found a definition of “right-of-way” in the current City of Detroit Zoning Ordinance which stated “a strip of land occupied or intended to be occupied by a street, crosswalk, railroad, sanitary or storm sewer, electric transmission line…….”

Door on narrow sidewalk. Definitely not allowed.

Door on narrow sidewalk. Definitely not allowed.

Door opening onto walking area of private property.

Door opening onto walking area of private property.

My assumed definition has always been the municipally owned sidewalk, street or alley. I have always exempted strip malls from the door opening clause.

Myths & Legends ,

Elevator Lobbies

May 11th, 2009


On a recent visit of a renovation of a high rise building, I noticed smoke dampers installed in transfer openings in a wall which formed a required elevator lobby.  As the construction documents were approved under 2006 Michigan Building Code, an elevator lobby is required at each floor where an elevator connects 3 or more  stories.  Previously, International Building Code and Michigan Building Code required these lobbies only when the elevator opened into a rated corridor.

elevator-shaft

Existing 2-hr masonry walls formed 3 sides of the lobby and approximately 6 ft of metal stud wall made up the remaining wall which I was inspecting.  2 HVAC penetrations were made in this wall one was ducted and the other was the transfer grille.

IBC/MBC 2006 require the walls that make up this elevator lobby to meet the requirements of fire partitions.  There is an exception, when the building has an NFPA 13 or 13R fire suppression system, that allows these walls to be smoke partitions.  The design professional chose to take this exception.  Let’s review the requirements for both.

fire-smoke-chart

As you can see, the fire partition will require a 20 min door, a fire damper and some firestopping, but by using the exception and denoting the wall as a smoke partition a smoke damper will be required for the transfer grill.  Smoke dampers are a more costly item, not only for materials but for labor charges because of its motorization and activation requirements.  The cost of the smoke damper would greatly outweigh the costs of upgrading to a fire door and joint/penetration firestopping.

It Pays To Know $$$

Welcome to michicode.com!

March 29th, 2009