General Instructions for the Designer
These general instructions for the designer are provided to ensure the
proper selection and installation of Simpson Strong-Tie®
products and must be followed carefully. These general instructions are in
addition to the specific design and installation instructions and notes provided
for each particular product, all of which should be consulted prior to and
during the design process.
- The term “Designer” used throughout this website is intended to mean
a licensed/certified building design professional, a licensed professional
engineer, or a licensed architect.
- All connected members and related elements shall be designed by the
Designer and must have sufficient strength (bending, shear, etc) to
resist the loads imposed by the anchors.
- When the allowable stress design method is used, the design service
loads shall not exceed the published allowable loads.
- When the ultimate strength design method is used, the factored loads
shall not exceed the design strengths calculated in accordance with the
published design data.
- Simpson Strong-Tie® strongly recommends the following addition
to construction drawings and specifications: "Simpson Strong-Tie
products are specifically required to meet the structural calculations of
plan. Before substituting another brand, confirm load capacity based on
reliable published testing data or calculations. The Engineer/Designer of
Record should evaluate and give written approval for substitution prior
to installation."
- Local and/or regional building codes may require meeting special
conditions. Building codes often require special inspections of
anchors installed in concrete or masonry. For compliance with these
requirements, it is necessary to contact the local and/or regional
building authority. Except where mandated by code, Simpson
Strong-Tie® products do not require special inspection.
- Allowable loads and design strengths are determined from test results,
calculations, and experience. These are guide values for sound base
materials with known properties. Due to variation in base materials
and site conditions, site-specific testing should be conducted if exact
performance in a specific base material at a specific site must be
known.
- Unless stated otherwise, tests conducted to derive performance
information were performed in members with minimum thickness
equal to 1.5 times the anchor embedment depth. Anchoring into thinner
members requires the evaluation and judgment of a qualified Designer.
- Tests are conducted with anchors installed perpendicular (±6°) to the
surface of the base material. Deviations can result in anchor bending
stresses and reduce the load carrying capacity of the anchor.
- Allowable loads and design strengths do not consider bending stresses
due to shear loads applied with large eccentricities
- Metal anchors and fasteners will corrode and may lose load-carrying capacity when installed in corrosive environments or exposed to corrosive materials.
- Mechanical anchors should not be installed into concrete that is less than 7 days old. The allowable loads and design strengths of mechanical anchors that are installed into concrete less than 28 days old should be based on the actual compressive strength of the concrete at the time of installation.
- Nominal embedment depth (embedment depth) is the distance from the surface of the base material to the installed end of the anchor and is measured prior to application of an installation torque (if applicable). Effective embedment depth is the distance from the surface of the base material to the deepest point at which the load is transferred to the base material.
- Drill bits shall meet the diameter requirements of ANSI B212.15.
- Threaded-rod inserts for adhesive anchors shall be UNC fully threaded steel.
- Allowable loads and design strengths are generally based on testing of adhesive anchors installed into dry holes.
- Adhesive anchors should not be installed into concrete that is less than 7 days old. The allowable loads and design strengths of adhesive anchors that are installed into concrete less than 28 days old should be based on the actual compressive strength of the concrete at the time load is applied.
- Adhesive anchors can be affected by elevated base material temperature.
- Anchors are permitted to support fire-resistive construction provided at least one of the following conditions is fulfilled: a) Anchors are used to resist wind or seismic forces only. b) Anchors that support gravity loadbearing structural elements are within a fire-resistance-rated envelope or a fire-resistance-rated membrane, are protected by approved fire-resistance-rated materials, or have been evaluated for resistance to fire exposure in accordance with recognized standards. c) Anchors are used to support nonstructural elements.
- Some adhesives are not qualified for resisting long-term sustained loads. These adhesives are for resisting short-term loads such as wind or seismic loads only.
- Exposure to some chemicals may degrade the bond strength of adhesive anchors. Refer to the product description for chemical resistance information.
