Match construction fasteners and anchors to the job
Metal construction fasteners and anchors will corrode and can lose load-carrying capacity when used in corrosive environments. The many variables in a single building environment make it impossible to accurately predict if, or when, significant corrosion will begin or reach a critical level. This makes it critical that builders and contractors know the potential risks and select a product coating or metal suitable for the installation. In addition, regular maintenance and periodic inspections should be performed, especially for outdoor installations.
To match construction fasteners, anchors or connectors for a job:
1. Identify the application – Consider the type of structure and how it will be used. Some fasteners have multiple applications, while others are designed for a specific installation type.
2. Evaluate the environment – The environment the connector or fastener will be used in is an important factor in the selection process. For example, indoor dry environments are less corrosive than outdoor environments. Exterior installations are categorized as dry in low rainfall environments with no regular exposure to moisture or wet in high moisture or rainfall environments. The most corrosive environments (called higher exposure environments) are areas where the fastener is exposed to ocean salt air, large bodies of water, fumes, fertilizers, soil, some preservative treated woods, industrial zones, and other corrosive elements.
3. Select the wood – The wood supplier should provide information on the wood being used, including the specific type of wood treatment used, whether ammonia was used in the treatment and the chemical retention level. If the data is not available, use stainless-steel connectors and fasteners.
4. Select the connector finish or material – When choosing the right fastener for the job, selecting the material is key. Determine what the fastener manufacturer recommends for the job and compare that to the wood supplier’s specifications. If they are different, use the more conservative recommendation.
Use load-rated screws for construction fasteners and anchors
Installing connectors with screws is easier, especially in overhead applications or when space is tight, and Simpson Strong-Tie has introduced load-ratedStrong-DriveSDstructural-connector screws. Designed to replace nails in some products, the SD screw has single-fastener load capacities that exceed those of 10d or 16d common nails.
A mechanically galvanized coating meets ASTM B695 Class 55 and is recommended for use in interior and most exterior conditions, as well as with certain preservative-treated woods.
The optimized shank is designed to match the fastener holes in Simpson Strong-Tie connectors. The hex head virtually eliminates cam-out and helps avoid stripping the head. The sharp point of the screw enables fast starts, and the serrated threads reduce torque for improved drivability.
SD screws are compliant with the 2006 International Residential Code (R319.3) and are available in two shank sizes – #9 and #10 in 1 ½- and 2 ½-inch lengths. For a list of Simpson Strong-Tie connectors approved for use with SD screws, visit www.strongtie.com/fasten (English only).