An Exterior Deck Structural Inspection

Penn Valley Engineering recently performed a structural inspection of an exterior deck in the Philadelphia, PA 19111 service area. The site visit included a limited visual inspection of a home with the purpose of examining the current structural condition of the rear exterior deck. Many homes, apartments, and condominiums in the Philadelphia area have exterior decks that add a wonderful amenity to an owner’s lifestyle. However, over time, their structural integrity can become questionable.

Exterior Deck Description

The exterior deck of this particular inspection was located at the rear of the home. The homeowner noted that the deck was installed approximately 34 years ago. The deck extended approximately 12’ 3” away from the rear of the home and was approximately 15’ 10” wide. The floor of the deck was approximately 8’ 3” above the rear exterior ground level. It was constructed of 2” x 8” dimensional lumber members at 16” on center. The deck was supported by a 2” x 10” dimensional lumber ledger board at the house. The rear of the deck was supported by a built-up double 2” x 10” dimensional lumber member beam resting on three 4” steel columns. The deck was accessed by a door in the rear wall of the home in the kitchen. Below the deck was a door access point to the basement and a garage door.

Modifications Made to the Deck

At the time of inspection, the entire structure of the exterior deck was viewable. The forward right portion of the deck (above the basement access door) had subsided by approximately 1-1/2.” This was due to a fracture in the ledger board at the forward right corner. The right portion of the ledger board (approximately 6’ in length) was modified to fit around the basement access door and the projection of the concrete foundation. The 2” x 10” dimensional lumber ledger board had been cut to a depth of 6-1/2” in this area.

Additionally, the ledger board had been significantly notched to accommodate a vent. The 2” x 8” floor joists had also been modified. They had been drilled and/or notched significantly to accommodate electrical runs. Furthermore, the deck subsidence in this area had periodically blocked the basement access door. The joist above the door had been shaved down significantly to allow the door to open.

Consequently, the above-noted drilling, notching, and shaving of structural members do not meet appropriate standards for modifications of structural lumber members. Additionally, the built-up double 2” x 10” dimensional lumber member beam that supported the rear of the deck was not plumb. The 4” x 4” lumber members supporting the deck railing had fractured at several locations. Overall, the deck deteriorated in accordance with its age and construction.

Risk of Collapse

Based on the present conditions, the rear exterior deck was at risk of collapse. PVE’s licensed engineer recommended that the deck be closed to use and not occupied or weight-loaded until properly repaired and/or replaced. The ledger board has already cracked and failed. Further use of the deck may lead to a sudden collapse due to the complete failure of the ledger board. The extensive structural issues and the overall deterioration of the deck due to age warrant a complete replacement of the deck in its entirety. The recommended structural engineering opinion is to remove and replace the existing deck structure with an appropriately designed deck structure.

Not only did our structural engineering firm perform an inspection of this exterior deck, we also provided an approximate construction cost estimate to the owner. Costs included the structural deck framing replacement and blueprints by our engineer.

Safety is a Priority

While an exterior deck is a wonderful thing to have on your property, complete structural stability and safety are of great concern. If you have structural questions about any feature of your home or property, call us. Put our observations and engineering experience to work for you. Schedule a visual inspection by a professional engineer licensed by the State of Pennsylvania. Fill out our form or speak with one of our engineers.

Call Penn Valley Engineering at (856) 829-8636 in the south Jersey/southeast Pennsylvania area. For exterior deck issues in Florida, our central Florida office is available at (321) 394-8026. Our structural engineering consulting firm would be happy to speak with you concerning any structural issue in your home or business. After that, we can schedule a licensed, professional structural engineer to meet with you and provide a summary narrative.

“I have been working with Penn Valley Engineering for several years at a Condominium Complex of 351 Units. They provided excellent service and at a reasonable price. I would highly recommend their services.”

– David K., reviewing structural engineering in New Jersey