Technical Library · Breyer
Design of Wood Structures
Ch. 1: Adjusting a lumber value: the table number is only a starting point
How long the load lasts, how wet the wood gets, and how many boards share the job all move the allowable stress. Here they decide whether a single 2×10 roof beam passes.
Ch. 2: Lag screws in the Ogopogo joints, checked against the NDS
What a 3/8 or 1/2 inch lag screw really holds in Southern Pine, why the grain direction can halve it, how many a joint needs, and the distances that keep the wood from splitting.
Ch. 3: Where the beam meets the post: bearing and notches
A beam can bend fine and still crush its own end on the post, or split at a notch cut to sit on it. Here is what the NDS says about both, worked on the roof beam.
Ch. 4: The roof post as an NDS column: stability factor and combined loading
Hibbeler used Euler buckling and a flat 1,000 psi crushing limit for the roof post. The NDS folds both into one stability factor, caps how slender a post may be, and has its own equation for weight plus wind.
Ch. 5: Fire tower legs: posts and timbers under the NDS
Hibbeler Chapter 7 sent the 16 ft tower legs to 6×6, and Chapter 12 offered bracing a 4×4 instead. Here is what each is worth under the NDS, and why a 6×6 is not just a stronger 4×4.
Ch. 6: Holding the roof down: bolts, steel plates and the uplift load
Hibbeler Chapter 3 found that wind wants to lift the foundry roof and said to use uplift-rated hardware. Here is what one through-bolt holds, what a steel plate adds, and why the net uplift is larger than first stated.
Ch. 7: Bearing at an angle and under washers: braces and bolt heads
A brace pushing into a post at 45° meets weaker wood than one pushing along the grain, and a bolt that pulls on its washer can crush the wood under it before the steel lets go.
Planned next, and what each is waiting on
- Shear at a bolted connection near a beam end (NDS 3.4.3.3), end-grain crushing of posts: The effective-depth definition for 3.4.3.3 is in Figure 3E, which could not be read; needs the figure from a text source before it is built. Compression-face notches (Ch. 3) and angled and washer bearing (Ch. 7) are done
- Steel plate and strap design, glued laminated timber, nails and screws: Breyer Ch. 6 covers bolts and 1/4 in steel plates on the wood side only; the plates themselves are AISC steel design, and glulam and nails are other NDS tables
- Rectangular timbers (6×8 and the like), eccentric loads on posts: Breyer Ch. 4 and 5 cover square posts; rectangular timbers are a different NDS category (beams and stringers, 4.1.3.3, graded for bending) and eccentric loads are NDS 15.4
- Wet and treated wood in service: Carries CM and incising into shear and the Ch. 15 sag check