Simple review can prevent hazards on Chicago porches

Recently, while completing a three-story stair tower and porch inspection, 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 structure 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 residents. This danger, all too common in Chicago, was made painfully clear recently when 13 young people were killed in the collapse of a wooden porch in Lincoln Park. 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 6x6 upright posts tied into the house or building face with a series of 6x6 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, or lookouts, of wooden porches, many other issues are of concern, per code standard, to Chicago residents. 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 shall 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.
Take a look at these above reference code standards and see how well your wooden porch measures up. Make sure the needed repairs are completed.

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 6x6 beams be missing within your wooden porch system, it is very possible that the floor joists or undercarriage is 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 2x8 or 2x10, needs to be secured to the exterior wall about every 6 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 4-inch maximum spacing requirement when measuring the outside of one picket edge to the outside of another picket edge.

As many as three quarters 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, Inc. a professional property consulting company specializing in commercial and residential property inspections and expert witness work.