URM Building Retrofit Applications
Explore Retrofit Applications
Parapet Bracing
A lot of damage to URM buildings can be attributed to parapet failures when a seismic or wind event occurs. The damage can occur not only to the building itself, but to nearby buildings, walkways, and driveways which poses a major risk to life safety and can increase recovery time. Bracing the parapets is a must when evaluating the needed retrofitting of a URM building.
Simpson Strong-Tie Products for Parapet Bracing
AT-XP® is a fast-cure, all-weather, high-strength anchoring adhesive and may be used to anchor threaded steel rods or deformed steel reinforcing bars in unreinforced masonry.
AT-XP High-Strength Adhesive
SET-XP® is a high-strength anchoring adhesive and may be used to anchor threaded steel rods or deformed steel reinforcing bars in unreinforced masonry.
SET-XP High-Strength Epoxy Adhesive
ET-HP® is an epoxy-based system for use as a high-strength, non-shrink anchor-grouting material and may be used to anchor threaded steel rods or deformed steel reinforcing bars in unreinforced masonry.
ET-HP Epoxy Adhesive
Screen tubes are used in hollow base material applications to contain adhesive around the anchor and prevent it from running into voids.
Steel Adhesive-Anchoring Screen Tubes
Holdowns are often used to resist out of plane forces, tying the wall to the roof or floor assembly. The HTT5-3/4 holdown uses a 3/4" diameter anchor bolt, which is typically required when anchoring into URM.
Holdowns
In retrofit applications, joist hangers might be used to support added blocking or might be installed horizontally to help resist out of plane anchorage forces in addition to their typical download and uplift load applications.
Joist Hangers
Retrofit and bearing plates are often used in out of plane wall to roof or wall to floor anchorage conditions and utilize a larger bearing surface on the side of an unreinforced masonry wall.
Retrofit and Bearing Plates
Straps may be used to resist out of plane wall to roof or wall to floor anchorage forces or drag forces when installed on the top or bottom of roof or floor framing. One out of plane force-resisting solution uses the MSTD Marriage Strap, an overlapping in-line splice between an HTT tension tie and a CMSTC16 coiled strap.
Straps
Angles transfer shear forces for wood to wood framing connections. The A35 with 1/2" long screws might be used to transfer shear forces from 1/2" minimum thickness sheathing to wood framing connections.
Angles
Hand-drive or collated screws may be used to enhance wood diaphragm strength. Strong-Drive structural wood screws may be used for connector or steel to wood connections.
Screws
Hand-Drive or collated nails may be used to enhance wood diaphragm shear strength or for wood to wood or steel to wood connections.
Nails