Balcony / Deck Failure


A common design characteristic of the H.O.A. developments is the inclusion of balconies or decks, and, if needed, exterior stair systems to access above ground dwellings. Improper design, manufacturing, or installation could result in a construction defect and damage. Unventilated areas with water intrusion cause dry rot, fungus, and mold. These may result in failure to the interior structural framing and exposure of plywood decking that may cause failure of the deck membrane.

Common Types:

  • Tongue and groove wood plank deck (fully adhered system).
  • Wood framed deck with elastomeric type coatings.
  • Lightweight concrete decks.

Common Problems:

  • Improper flashing.
  • Improper deck to sliding glass door or front door threshold transfer.
  • Improper deck to wall transition.
  • Improper drainage or slope to drain.
  • Improper deck finishing (coatings).
  • Improper installation of deck scupper drains.

Possible Damage:

  • Dry rot.
  • Deck/structural failure.
  • Interior leaks.
  • Stucco staining/cracking.
  • Wood destroying organisms.
  • Surface cracks or cheecking.

Why Some Balconies Fail

There are four common problem areas in the construction of balcony surfaces. 

Balcony / Deck Failure

 1.  Not Enough Vertical Offset at the Door Threshold.

There should be 1-1/2 inch vertical separation between the interior and exterior surface is recommended:

  • to avoid wind-driven water from getting inside.
  • to provide a vertical surface to attach the waterproof membrane.
  • to provide continuous "Z" -metal flashing.

2.  No Waterproofing on the Sides of the Balcony. The waterproof membrane should be extended up the vertical surface about 1-1/2 inches to create a continuous waterproof membrane along the balcony sides.

3.  Insufficient Slope. Adequate slope of the balcony surface is needed to let water drain off fast. A 1/4-inch-per-foot slope from the wall to the drain and/or scupper is recommended for proper drainage.

4.  No Ridge to Deflect Water to the Scuppers is an Enclosed. Balcony Without a ridge, commonly called a cricket or saddle, at the low end of the balcony, the water will puddle between to the drains or scuppers.

Information provided by Building Analysts, a full-service architectural and engineering firm with many years of experience in construction litigation. Their services include: architectural and structural investigations, repair recommendations, preparation of exhibits and expert testimony. Contact Building Analysts Toll Free at: (800) 352-1497.