| In a recent safety evaluation of residential decks | | | | the deck's band board, through the house band |
| in and around Charlottesville Virginia an alarming | | | | board or other framing member, and are secured |
| trend was noted. 7 out of 10 decks had at least | | | | with a washer and nut on the other side. When |
| one safety issue, and 4 of the decks had | | | | this is not possible, lag bolts must be used and |
| significant safety issues that were cause for | | | | must be secured into the framing members of |
| immediate action. Most homeowners either hire a | | | | the house. |
| contractor to build the deck, or the deck was | | | | The next serious issue noted was found with the |
| attached to the house when the home was | | | | fastening of the deck joists to the deck band |
| purchased. Some of the most serious issues | | | | board. Again, in nearly half of the decks inspected, |
| found were: | | | | the joists were merely toe-nailed to the band |
| - Insufficient methods of attachment to the | | | | board, and/or toe nailed and sitting on a 2X2 inch |
| house | | | | ledger block placed under the joist. The same |
| - Improper joist fastening | | | | issues of poor pull out resistance and load carrying |
| - Insufficient lateral bracing | | | | ability apply here. The only correct way to fasten |
| - Improper or non-existent post attachment | | | | deck joists is to utilize a metal joist hangar. They |
| - Undersized framing members | | | | are designed to carry the load and withstand |
| - Improper fasteners used | | | | lateral forces when used properly. Check under |
| The most serious issue, insufficient attachment to | | | | your deck. If you do not see joist hangars, nailed |
| the house, was found on almost half, 4 of 10, of | | | | at 90 degrees into the band board of the deck |
| the decks inspected. When a ledger board, or | | | | and into the joist, your deck is not safe! |
| band board (the framing member of the deck | | | | Most of the decks inspected utilized 4X4 treated |
| that is fastened to the structure of the house, to | | | | wood posts that were both buried in the ground |
| which the joists of the deck are attached) is | | | | below the frost line and sitting atop a proper |
| fastened to the house improperly, the deck is a | | | | concrete footing. A few of them were not. Two |
| critical risk for collapse. Ledger boards MUST be | | | | of the decks had 4X4 posts literally just resting |
| fastened to the house using either lag bolts that | | | | on top of concrete, with no attachment method |
| fasten securely to the rim joist or framing of the | | | | to the concrete. If you are not burying the post |
| house, or carriage bolts that completely penetrate | | | | at least 2 foot below grade, then you must utilize |
| the framing of the house and are secured with a | | | | a metal post base bracket. The post base it |
| washer and nut on the other side. The issues we | | | | attached to the concrete using the appropriate |
| saw included the use of nothing more than 16 | | | | concrete fasteners, then the post is attached to |
| penny nails, lag bolts that missed the house | | | | the bracket using joist hanger nails or lag bolts. |
| framing members and were fastened only to the | | | | Next, a serious lack of lateral bracing on most of |
| exterior sheathing (plywood) and on one case, | | | | the decks was noted. Lateral bracing prevents the |
| standard wood screws. Improper fastening | | | | deck structure from moving sideways. If you |
| techniques and materials is the #1 cause of deck | | | | were to start out taking a few steps on one |
| collapse, leading to injury and death. When a deck | | | | direction on your deck, and stop suddenly with |
| is utilized for entertaining, the shift in load when | | | | force, your deck should NOT MOVE. If it does, it |
| people move about on the deck also shifts the | | | | is not properly braced. Your deck should be at |
| stresses on the deck structure. The more people, | | | | least as strong as the floor inside your home, and |
| the more weight, and the greater the forces | | | | often stronger. The exterior sheathing on the |
| involved. One of the decks we inspected was so | | | | structure of your house provides the lateral |
| poorly constructed, one person's weight was | | | | bracing. On a deck, it needs to be done with |
| enough force to cause to deck to sway slightly. | | | | dimensional lumber that is designed to withstand |
| Put 20 people on that deck, and everyone is at | | | | exposure to the elements. When properly planned, |
| risk. | | | | a deck's lateral bracing can be incorporated into |
| 16 penny nails are just not thick enough to | | | | the design so that it adds to the appearance of |
| withstand heavy loads and have very little | | | | the deck while providing a structural purpose. If |
| strength to withstand lateral forces to resist | | | | your deck is built on grade, or less than 24 inches |
| pulling out. Any adult can pull a nail with a hammer | | | | above grade, lateral bracing will need to be applied |
| claw using about as much force as is equal the | | | | before the deck surface is placed. On decks more |
| force of 30 pounds of weight. Put 20 people, over | | | | than 24 inches above grade, an angled piece of |
| 2,000 pounds of weight force, on a deck | | | | dimensional lumber should be fastened to each |
| fastened with nails, and you see the problem. | | | | side of each post, from the top of the post to |
| Nailing, bolting or even lag screwing to the exterior | | | | some point below the top, with a minimum of a |
| sheathing of the house is essentially useless. Most | | | | 30 degree angle. If you have a deck, get it |
| exterior sheathing products are less than 1/2 inch | | | | inspected by a professional immediately. An |
| thick. They are designed to supply lateral | | | | inspection should take about an hour, and cost |
| (sideways) strength to a structure, not to resist | | | | less than one hundred dollars if you call a |
| pull-out forces. The best method of attachment is | | | | contractor. A small price to pay for peace of |
| to utilize carriage bolts that go completely through | | | | mind. |