blocking to secure the ply we'd and bolted and provided the connection with the floor i'm joined by thor madison >> thor structural engineers and thor knows more about sheer walls than anybody i've met in my life. >> it provides the stable ability that would rock before and after during around earthquake the nails along the edge of the plywood will reduce the chance of the building falling down. >> what else should we consider in getting ready. >> one thing about plywood a natural material that absorbs moisture and the panels can swell depending on the moisture if they swell they'll bulk out it is important probation officer leave a gap between the panels so before we install the next panel we'll drive in a couple of nails used to as temporary spares. >> what are the nails. >> 16 penny singers a good saying that and we don't need to be concerned with the exact nail size only the gap the next panel will be held with the existing panel we'll pull those down. >> we have peter from the construction why not go outside and cut our second panel so, now we've got the plywood let's go ahead and get it pu