Design for Force Transfer Around Openings (FTAO)
Technical Note
Force transfer around openings (FTAO) is a popular method of shear wall analysis for wood-frame buildings. The use of FTAO analysis varies, as published design examples typically assume the wall is symmetrical around a single opening and this design method had not been tested until recently.
This publication is designed for: architects, engineers, designers, code officials
This technical note presents a rational analysis for applying FTAO to walls with asymmetric piers and walls with multiple openings. It is based on APA modeling and testing and uses methodology that assists the design professional in solving for the required sheathing, nailing, hold-downs, straps and maximum deflection.
In addition to this technical note, APA has developed a free, worksheet-based Force Transfer Around Opening calculator.
Key sections include:
Shear wall design challenges
History of FTAO research at APA
FTAO detailing
Design assumptions and procedures
Example: FTAO calculations with two window openings
Published by APA — The Engineered Wood Association.
