Slide 25 of 67
Notes:
- Successful Plywood Coverage
- This apartment building demonstrated the success of full plywood coverage. This building is located in the heart of the earthquake-damaged portion of Northridge. It was built in 1982 for about $1 million; an extra $50,000 was spent on the plywood and hold-downs. At the time, the builder took “heat” for his decision. After the quake, he was a hero. The lots on each side of this building are now vacant because of the damage in the quake, while this building stayed occupied and suffered very little damage.
- This building offers proof of the effectiveness of covering the entire building with plywood instead of just the corners. The way that it acted during the quake has served to change the design ideas for the whole of Los Angeles.
- What plywood performed the best?
- The best plywood sheathing is Structural 1 grade with a minimum of four-ply panel construction.
- Three-ply plywood panel construction tore at its inner ply seam.
- For this reason, prescriptive standards often specify five-ply plywood for shear wall sheathing.
