Connections

Attachment Of Scissors Trusses

Question: 

What is the correct method of attaching scissors trusses to the top plate? I read recently in a trade magazine that this type of truss should be toe-nailed on one end and attached with slotted clips on the other end. According to the article, this is to allow for movement of the truss. We require PE stamped spec sheets from the truss manufacturer to verify trusses meet wind and snow loads. These sheets give bracing requirements but never give recommended attachment requirements.

Metal Connector Plates In Fires

Question: 

I am thinking of using wood trusses for the roofing/ceiling structural systems on some houses I shall build. I remember, though, an engineer/volunteer fireman commenting back in 1989 that the connector plates are prone to expand and pop off, early on in a fire, causing catastrophic structural failure. Was this the case, and if so, has this problem been corrected?

Safety Issues With Design Dead Loads

Question: 

Can I safely install 3/4 in. T&G, OSB on 2x4 trusses that are 24 in. O.C.? My roof was installed over 5/8 in. plywood without clips that have caused a lot of sagging and the shingles need replacing. I want to “fix” it one time and install architecture type shingles, but the garage is 24 ft. wide and 28 ft. long without any load bearing walls. My concern is the weight on the trusses. 5/8 in. plywood weighs 52 lbs. and the OSB weighs 78 lbs. for each 4 ft. x 8 ft. sheet. The roof will require about 84 4 ft. x 8 ft. sheets to cover, which equals about 2,184 lbs.

Jack Truss Connections To Girder

Question: 

In a hip roof application where jack trusses connect to a girder truss using pressure blocking (power blocking), what is the proper installation and the span that is acceptable before a hanger is required?

Deck Ledger Attachment to Residential Wood Truss Floor Systems

This Research Report provides construction details for residential deck ledger attachment to metal plate connected wood truss floor systems. Proper attachment of the deck ledger to the house is critical for ensuring that an “attached” deck is safely and securely supported at this location. 

Exterior Brick Masonry Veneer Supported by Wood Trusses

Code compliant use of Metal Plate Connected Wood Trusses (MPCWT) to support brick veneer can be accomplished by both individual designs and by adhering to the recommendations that follow within this report. This discussion focuses on a common use of MPCWT’s; the gable end at the transition from a wider section of a building to a narrower section.

Overdriven Nails in Structural Sheathings - Educational Program

This presentation provides information on overdriven nails in structural sheathing.

Heel Blocking Requirements and Capacity Analysis - Educational Program

This presentation provides information on heel blocking requirements and related analysis.

Conventionally Framed Roofs & Roof Trusses: Code-Compliant Construction

This Research Report reviews pertinent sections of the 2006, 2009 and 2012 International Residential Code (IRC), the 2012 IRC Commentary, and additional sources in an effort to compile the related data and identify discrepancies or omissions. The focus is catered toward meeting and better understanding the requirements for conventionally framed roofs and roof truss construction per IRC Section R802. 

Heel Blocking Requirements and Capacity Analysis

Both the International Residential Code (IRC) and the International Building Code (IBC) require that the top plates of exterior braced wall panels be attached to the rafters or roof trusses above. This report will discuss the code requirements and provide alternate engineered designs and capacities, including heel/bird blocking, partial height blocking and blocking panels.