Archive for the ‘Myths & Legends’ Category

Single Family Garage Separation

November 16th, 2009

garage separation 003A separation between the dwelling and a garage is a subject full of misconceptions.  “It’s a firewall….it has to have two layers of 5/8 gyp board on the garage side…., the door has to be a fire door with a closer are popular fallacies.   I can only speak for the last 20 years of CABO and BOCA requirements for separations,  but none of these have ever been required.  Here is what is required by the IRC 2006:

  1. You can’t have an opening into a garage from a bedroom.
  2. If you have duct work penetrating into the garage, it has to be made of a minimum of 26 ga sheet metal and cannot open into the garage.
  3. Other penetrations of the separation wall must be fireblocked.
  4. The garage shall be separated from the dwelling (including its attic) by ½ inch gyp board on the garage side (you could theoretically have open studs on the dwelling side).
  5. If there is a habitable room above the garage, the separation must be 5/8 gyp board (type X).
  6. The supporting structure of item 5 shall be protected by ½ gyp board.
  7. If there is a door in the separation wall, it must be either 1 3/8 inch solid wood, solid or honeycomb steel minimum 1 3/8 inch thick, or a 20-minute fire-rated door. (Wouldn’t a fire-rated door require a closer and positive latching?)

Myths & Legends, Residential Code

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 ,