Framing Techniques for Builders: Lessons Learned and Best Practices

Transcription

1 Framing Techniques for Builders: Lessons Learned and Best Practices Gary Schweizer, PE Weyerhaeuser August 29, 2017 Disclaimer: This presentation was developed by Weyerhaeuser and is not funded by WoodWorks or the Softwood Lumber Board.

2 The Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES), Provider #G516. Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 Course Description This interactive session builds on the idea that builders can improve framing techniques through the lens of others challenges and solutions. Recent commercial and multi-family construction hurdles related to issues with building framing schemes will be reviewed through case studies and lessons learned. Best practices that builders can employ to avoid similar issues on their own projects will be discussed, and the audience will be asked to participate and apply practices reviewed during the session. Attendees will leave prepared with design strategies to produce high-performing structures and methodologies that can be considered and applied in construction immediately. This is an interactive discussion; questions and comments are welcomed.

4 Learning Objectives 1. Highlight common framing issues in commercial and multi-family structures and discuss best practice solutions. 2. Discuss proper load path framing techniques for wood-frame structures. 3. Review lessons learned from five different project case studies. 4. Examine construction strategies that can result in high-performing structures in terms of durability, energy-efficiency and other quantifiable measures.

5 A bit about me Academics - BSCE - The OhioState University - MBA The University of Dayton Experience - - ConsultingStructural Engineer Columbus,Ohio (7 years) - Wood Products/Structural Engineering Trus Joist/Weyerhaeuser (30 + years) Registered ProfessionalEngineer/Structural Engineer Expertise Design & Analysis, Forensics, Litigation Support

6 Agenda - Lessons Learned Load Path Resolution Vertical & Lateral Lateral Stability Differential Deflection Unique Floor/Fascia Requirements Moisture Management Keep it Dry Preservative Treatments Protecting Products in Inventory & Jobsites Vibration Fire & Sound Design

7 Load Path Resolution Simple stated vertical and lateral loads need to be transferred to the foundation/ground. Load rationalization = Truss/Rafter/Joist à Beam à Column à Foundation Proper member selection Adequate support Appropriate load transfer details Foundation adequacy Software 2d analysis; 3d view; review of software operator design

8 Simplifying Visualize the Loading Tree Floor Joist ò Beam ò Column

9 Load Path Resolution Member Analysis what to watch for? Vertical Loads Increased Dead Loads lightweight concrete, tile or stone, non-load bearing walls Offset Walls & Cantilevers Concentrated Loads (Fc perp of Fc parallel) Beams & Headers Girder Truss Differential loading conditions Lateral Loads Location of Shear Walls connection design; manufacturer s limitations (o/c spacing) Blocking Screws vs. Nails Installation Review In other words - Sequence the Framing

10 Framer Instruction Guide

11 Assumptions Follow-up EXPECTATIONS OF THE CONTRACTOR OFA Review Framing for correctness Notes and deviations Notes are acceptable unless noted otherwise EXPECTATIONS OF THE SUPPLIER Highlight deviations Load rationalization Value engineering professional protocol Framing details

12 Failures Can Occur Apartment Project (student housing) Nashville, TN Initial Complaint Floor Levelness, Water Leaks Construction Issue Improper Load Transfer; Rim not under the load bearing wall Squash Blocks added to Stabilize the Structure What could the EOR/AOR have done better? Load Transfer detailing; wall stacking What could Weyerhaeuser and dealer have done better? Protocol communications

13 Differential Deflection Complaint Tile Cracking Excessive Deflection dropping 5/8 over 4

14 Differential Deflection

15 Field Investigation Results Transit Floor Readings Potential for Differential Deflection Beam set too high!

16 Best Practices - Differential Deflection Anticipate different span and loading conditions Feather framing - simple vs. continuous span Match deflection performance beam vs adjacent joists Acknowledge different support conditions (wall vs. beam)

17 Moisture Management Simple stated keep it dry or use preservative treated wood Guiding Principles Dry Usage is classified as 16% Reasonable construction rainfall is OK Service Life - Keep it Dry When in doubt Preservative Treated Wood Dry Use Conditions - what to watch for? Balcony/Deck Conditions Flashing, connections, detailing, etc. à waterproofing Allow for wicking don t encapsulate Installation Review Maintenance Program

18 Moisture Management Roof/Floor not Watertight Waterproof Deck Membrane Alberta, Canada 150 degree differential Waterproof Roof Membrane Sacramento, California Closed Plenum

19 Moisture Management Condos La Jolla, CA Balcony Framing Partial Roof Watershed Dry-Use not assured Moisture Intrusion/ Wicking

20 Moisture Management Berkley, CA Balcony Deck Collapse 2015

21 Moisture Management Selecting the Correct Preservative Treatment Exposure 4A Phillip Merrill Center, MD Exposed Heavy Timber CuAz Treated

22 Vibration Factors Affecting Floor Performance

23 Vibration Design Fundamental Frequency f (Hz) E MOE (psi) I - moment of inertia (in 4 ) W true dead load (lbs.) L - joist span (in) Virginia Tech Guidelines

24 Quick Rules of Thumb Floor covering/floor membranes Shorten the span Increase the joist depth L/480 + Glued/Screwed floor decking Bridging/Ceiling tied to a support wall

25 Fire & Sound Design

26 Product Application Assurance Specification Prescribed Code vs Preferred Standards Full Floor Specification - Finished Floor Coverings Sound Mats Perimeter Isolation Installation Matching Specification Manufacturer s Recommendation Isolation/De-Couple

27 Park Place; Fountain Hills, AZ

28 Fire & Sound Design Type 3 Construction Requires FRT Wood Framing (Type A Flamespread ¹FRTW) Fire-Retardant-Treated Wood Must be Impregnated with Chemicals (2018 International Building Code) FRTW in accordance with ASTM E84 or UL723. Field Applied Coatings ¹Manufactured FRT Products Quality Control, plant vs. field environments, etc.)

29 Type 3 FRT Wood Framing

30 Code Approved FRTW Field Issue Apartment projects in Minneapolis non-code approved FRT requires replacement (2x6 and 2x8 perimeter framing) On Big-D s watch, lumber that was not approved or code-compliant was used on the Hello Apartments project and Golden Villas will not tolerate actions that create any risk for future tenants," Golden Villas Chief Manager Traci Tomas said in a news release.

31 Summarizing - My Personal List to allow for caution Tight Construction Timeline (design/modify as you go ) à frequent communications, documentation Dimensional Issues/Construction Tolerances (field measurement, pre-cut holes/locations, concentrated load alignment) à design and installation review Floor Covering Lightweight Concrete Topping, Tile/Stone Cracking à expansion joints, differential deflection, concentrated loads Manufacturing Defect à urgency for communication and decision making Installation Issues à inspection, concurrence to architecturals and framing plans

32 Summarizing - My Personal List to allow for caution Deflection define client/customer expectations à differential deflection, Non-Load bearing walls Assumptions à Architectural Discrepancies, Framing Irregularities, Professional Protocol Floor Performance à define client/customer expectations; floor system parameters Moisture Design à Dry Use, correct preservative treatment Load Tracking à rationalize loads to the foundation

33 Product Application Assurance

34 Questions? This concludes The American Institute of Architects Continuing Education Systems Course Gary Schweizer, PE Weyerhaeuser