Engineering

2018 North Carolina Residential Code Prescriptive Tables for Selection of Support Elements for Beams, Girders, and Headers: Example Problems

The tables are intended as a practical tool to assist contractors in the selection of footing widths and the determination of the quantity of wood studs required for supporting the end reactions of beams, girders, and/or headers. 

Put Out the Design Fire Before it Starts

Getting information up front on sprinkler systems can ease the design process.

Rock the Block

CM increases profit with pre-designed shear blocking panels.

Thinking Through a Curve

A complex roof with multiple arcing panels provided design challenges both before and during construction.

The Best Way Forward is a Solid Path Downward

A best practice for building designers: find a friend to check your load paths.

Lumber Design Values

No matter the species, component manufacturers (CMs) purchase and rely on the accuracy and reliability of many different lumber design properties, including: bending (Fb); shear parallel to grain (Fv), compression perpendicular to grain (Fc^), compression parallel to grain (Fc), tension parallel to grain (Ft), and modulus of elasticity (E and Emin).

Wood Three Hour Fire Assembly

Question: 

Is it possible to construct an assembly for ceiling between first and second floors using 2x with few layers of gypsum to obtain a 3-hour fire rating?

Determining Earthquake Loads

Question: 

We are currently developing a project which specifies “Seismic Design Category C.” We are an East Coast truss manufacturer and have not encountered seismic requirements before.

Warning Poster Caution Notes

Question: 

We are concerned with SBCA’s BCSI-B1 Summary Sheet which under “Notes” makes a disclaimer. Our concern is if there would be an accident with our trusses and we point out that the bracing was not placed correctly according to SBCA documentation, which is sent with every job. If the accident goes to court, how will our attorney respond when the opposing attorney points out the disclaimer, which infers that the bracing we recommend must be flawed, otherwise it would not be disclaimed?

Truss Bracing At Supports

Question: 

I almost always see wood trusses erected with no stability bracing at points of support. It seems to me that common sense and section 3.3.3.4 of The American Wood Council’s National Design Specification for Wood Construction (NDS) require that lateral support be provided at points of bearing. Plywood decking doesn't provide any more restraint for a wood truss than it does for a roof joist. I doubt if it was a concern with short span trusses having 4 in.