August 9th, 2009
Today InterNACHI released a free, online Deck Inspections course. The new course teaches the inspector to perform residential and commercial wood deck inspections. It includes a review of all common deck defects. And, in keeping with InterNACHI’s commitment to continuing education, this deck course is open and free to all members and can be taken again and again, without limit.
The Deck Inspections course includes:
- 35 sections;
- 80 photos, diagrams and custom graphics;
- 5 quizzes;
- a 25-question final exam (drawn from a larger pool);
- instant grading;
- a downloadable, printable Certificate of Completion; and
- accreditations and state approvals.
The course covers the following categories:
- Course Objectives
- Decks and Similar Structures
- Decks Defined
- From the Ground Up
- Deck Load
- Footings and Posts
- Wood Decay
- Moisture and Wood Decay
- The Pick Test
- Support and Connections
- Girders and Beams
- Ledger Connections
- Framing Around
- Cantilevered Decks
- Connections and Fasteners
- Posts and Rails
- Guardrails and Supports
- Board placement and Support
- Stringers, Risers and Treads
- Electrical Receptacles
- Receptacle Requirements
- Weatherproof Receptacles
- Other Considerations
- Location and Egress
Upon completion of the Deck Inspections course and passing of the 25-question final exam (drawn from a larger pool), the student can download and print their own Deck Inspections course Certificate of Completion which is auto-generated in their own name.
The student’s (InterNACHI member’s) information is recorded on InterNACHI’s servers for membership compliance verification, and automatically logs completion into InterNACHI’s online Continuing Education log. It counts as three (3) InterNACHI Continuing Education hours.
July 15th, 2009
More than 2 million decks are built and replaced each year in North America. InterNACHI estimates that of the 45 million existing decks, only 40% are completely safe.
Because decks appear to be simple to build, many people do not realize that decks are, in fact, structures that need to be designed to adequately resist certain stresses. Like any other house or building, a deck must be designed to support the weight of people, snow loads, and objects. A deck must be able to resist lateral and uplift loads that can act on the deck as a result of wind or seismic activity. Deck stairs must be safe and handrails graspable. And, finally, deck rails should be safe for children by having proper infill spacing.
A deck failure is any failure of a deck that could lead to injury, including rail failure, or total deck collapse. There is no international system that tracks deck failures, and each is treated as an isolated event, rather than a systemic problem. Very few municipalities perform investigations into the cause of the failure, and the media are generally more concerned with injuries rather than on the causes of collapses. Rail failure occurs much more frequently than total deck collapses; however, because rail failures are less dramatic than total collapses and normally don’t result in death, injuries from rail failures are rarely reported. Here are some interesting facts about deck failure:
- More decks collapse in the summer than in the rest of the year combined.
- Almost every deck collapse occurred while the decks were occupied or under a heavy snow load.
- There is no correlation between deck failure and whether the deck was built with or without a building permit.
- There is no correlation between deck failure and whether the deck was built by a homeowner or a professional contractor.
- There is a slight correlation between deck failure and the age of the deck.
- About 90% of deck collapses occurred as a result of the separation of the house and the deck ledger board, allowing the deck to swing away from the house. It is very rare for deck floor joists to break mid-span.
- Many more injuries are the result of rail failure, rather than complete deck collapse.
- Deck stairs are notorious for lacking graspable handrails.
- Many do-it-yourself homeowners, and even contractors, don’t believe that rail infill spacing codes apply to decks.
A proper deck inspection relies heavily on the professional judgments of the inspector. This article will help improve the accuracy of those judgments.
Many thanks to InterNACHI staffer Lisa Vega for creating the awesome deck graphics.