Since 2006, the North American Deck & Railing Association (NADRA) has annually promoted “Deck Safety Month” each Spring. The program raises awareness among consumers about the need to inspect their deck and can help them prepare for the outdoor entertaining season. Homeowners who are assessing the safety of their decks may ask an Architect to provide a more thorough inspection.
NADRA has produced a comprehensive, four-page checklist that homeowners can use to delineate any concerns found during a preliminary deck inspection. This checklist can ensure the homeowner that a thorough investigation of every aspect has been completed and all issues will be addressed.
The checklist notes these eight key areas to be inspected:
1. Ledger Connections: Older decks in particular are susceptible to pulling away from the home if this connection was installed incorrectly or has corroded. The type of connection (lag screw, machine bolt, etc.), its diameter and length, and the material supporting the deck should be noted. The deck should connect to a wood rim joist, concrete or block and not to a brick or masonry veneer. Flashing should also be installed above the ledge and behind the exterior cladding.
2. Posts and Footings: Note the post size and type of concrete to post connection. Footings should be at least 1 foot to 3 feet into undisturbed ground depending upon the local frost line. Check for signs of decay, corrosion or other weakening.
3. Post to Beam Connection: Determine if the connection has been bent or modified which can cause fractures and should be replaced. Also ensure that girders are not positioned alongside the posts and connected with a metal fastener (bolt or lag screw) providing the bearing. This is prohibited due to the chances of failure.
4. Joists and Connections: Look for a minimum of 1-½ inch of bearing as required by code. Nails in ledger strips are subject to withdrawal and are prohibited by the code. If used, ledger strips should be nailed directly underneath the joist with three or four nails (depending upon the standard). Also look for any modifications to the connections and any signs of corrosion.
5. Stairs: Check that the triangular opening formed by the riser, tread, and guard bottom is less than 6 inches. Also look for corrosion on connections and ensure all are in place and secure.
6. Deck Boards: Be certain that fasteners are tight and recessed. If composite or PVC deck boards are used, check that the spacing meets the manufacturers’ guidelines.
7. Railings: Measure the railings to be sure they are at least 36 inches high and ideally 42 inches high. Note what type of shear connection exists between the post and frame. Check that the opening is less than 4 inches between the balusters on the deck and on the stairs.
8. Other Areas: Check that all fasteners still have their finish, that all connector holes are properly filled and that all bolts have washers on both sides of the connection.
For copies of the evaluation checklist that can be filled out by the homeowner, visit the NADRA web site at: http://www.nadra.org/Deck_Evaluation_Form.pdf
For assistance in conducting a deck inspection at any time of the year, contact: Charles J. Collins, Jr./Architect at 609-654-2329 or at archcjc@aol.com.