Simple review can prevent
As
spring rolls around and the weather improves, city residents will
take to the outdoors, and for many of us, that means making use of
that longstanding Chicago tradition, the porch. Unfortunately, as
we learned at great cost during 2003 when 13 young people died in
a Lincoln Park porch collapse, many of the city’s wooden porches
are not safe. Not
long ago, I was inspecting a three-story stair tower and porch in
Chicago when I reached out and grabbed the two 30-foot posts, or uprights,
and attempted to move the structure simply by shifting my weight from
one foot to the other while pushing on the posts. To my horror, the
entire thing shook as if it was on the receiving end of a gale-force
wind. This
porch had recently been repaired, though obviously not well, and like
countless wooden porches across the city, it posed a hazard to the
building’s residents. The following information is designed to
help condominium owners and renters decide whether their porches are
safe. If your porch seems unsafe, call the city for an inspection
at 312-744-4000. The
typical wooden porch includes a series of 6-by-6 upright posts tied
into the house or building face with a series of 6-by-6 lateral or
“lookout” beams. The lateral or horizontal beams hold the
posts in place through the use of metal ties and fire-cut notches
secured with nails. The metal ties are attached to the wooden lookouts
by nails or screws and rest firmly behind the building masonry wall,
leaving the ties buried in the brick surface. In
a well-designed porch, the lookout cannot be pulled away from the
building. This becomes important in case of a fire, as the secure
lookout, when burned through, will collapse into the building rather
than away from it. The
fire-notched section of the lookout is tied into the upright post,
leaving an exposed triangular section that is securely fastened to
the post, usually with nails. During a severe fire or collapse the
notched area will pull the porch into itself, helping to hold it together
and limiting the spread of fire. Look
for the fire notch at the end of the beams, and look for the steel
strap at the building’s wall, confirming that the porch structure
is tied into the building as it should be. In
addition to the uprights and laterals, every stair must be kept in
sound repair, and every stair more than two risers high must have
rails not less than 30 inches tall. Every porch more than two risers
high must have guard rails not less than three and a half feet above
the floor of the porch. Rails
and balusters must be firmly fastened and maintained. Supports and
porch floors must be in good condition, not rotting, and no flight
of stairs should have settled or moved from its intended position
by more than an inch. Every stair tread must be level and strong enough
to bear a concentrated load of at least 400 pounds without danger
of breaking. In
addition to the uprights or posts and laterals described above, your
wooden porch must typically meet minimum design load calculations
of 50 pounds per square foot. An architect, carpenter, home inspector
or city official can help you make sure your porch meets this standard. Should
lookouts or lateral 6-by-6 beams be missing within your wooden porch
system, it is very possible that the floor joists or undercarriage
are not properly attached to the building’s exterior wall. This
is dangerous. Before jumping to this conclusion look for metal u-shaped
brackets or saddles, which should be nailed into your floor joists
and into a porch ledger, which sits horizontally along the building’s
exterior wall. This ledger board, usually a 2-by-8 or 2-by-10, needs
to be secured to the exterior wall about every six feet. Nails are
not considered adequate fasteners when ledger boards are attached
to exterior walls. Wooden
porch stairs are usually limited to an 8.25-inch riser (the vertical
stair part) and an 11.25-inch tread depth. This design detail is evident
in more than 90 percent of Chicago wooden porches that this inspector
has seen. Should there be a deviation in riser height of more than
3/8 of an inch, the riser height is considered suspicious and the
flight of stairs hazardous. A
simple screwdriver can be used as a probe to check for wood-rot within
the structural components of the porch. Push the screwdriver blade
into the porch uprights or posts, the porch laterals or lookouts,
and the porch stairs. Should the blade easily penetrate the surface
and plunge into the heart of the wood, repair is needed. In addition,
confirm that the handrails and guardrails are secure and properly
joined to the porch structural members. Handrails and guardrails typically
have a four-inch maximum spacing requirement when measuring the outside
of one picket edge to the outside of another picket edge. As
many as three-fourths of all wooden porches that our company inspects
need some significant repairs immediately, but a quick inspection
by residents can make porches safer throughout the city. Thomas Corbett is president of Tomacor, www.Tomacor.com, a professional property consulting company specializing in commercial and residential property inspections and expert witness work. Questions can be emailed to TCorbett@Tomacor.com. |