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Q.We're remodeling a 1930s vintage San Diego home and have to seismically reinforce its cripple walls with plywood, shear transfer plates, and hold-downs. Because all the framing is very dry and most of the cripples measure only 1 foot to 2 feet in length, I'm worried that the 2x4s will split when I nail up the plywood. Is predrilling the nail holes necessary? Also, there are three full-length beams in the crawlspace supporting the floor joists, with short columns mounted on concrete bases supporting the beams on 6-foot centers. How should I address the connections between these joists, beams, columns, and bases?

A.Howard Cook, of Bay Area Retrofit in Berkeley, Calif., responds: Since the home was built in 1930, it's probably framed with old-growth, full-dimension, close-grain Douglas fir lumber, a framing material we've found practically impossible to split.

You can experiment on a cripple stud by nailing slightly staggered nails 2 to 3 inches on-center to see if it splits, but I doubt it will.

If it does, predrilling (typically with a drill bit sized slightly smaller than the 0.131-inch diameter of an 8d common nail) is an option, but it's slow, which is why we prefer to use 15-gauge electro-galvanized staples when fastening plywood shear panels onto short, new-growth 2x4 studs or blocking.

To meet or exceed APA guidelines for wood structural panel shear walls (see APA Research Report 154, Form Q260, available at www.apawood.org), we use 1 3/4-inch-long staples with 1 5/32-inch structural I-rated plywood sheathing, slightly staggering (by about 1 inch) the staples from the stud's centerline.

Because staples can rust through more quickly than thicker-diameter nails, we use stainless steel staples whenever we suspect moisture might be a problem.

While a lot of money has been wasted on fancy straps and connectors, it's interesting to note that none of the existing seismic retrofit guidelines (such as Chapter A3 of the International Existing Building Code) address the connections between floor framing support members.

Since even modern building codes address these connections with only a few toenails, check and make sure the tops and bottoms of the posts are nailed so that they cannot be knocked loose. They're sometimes hard to see because the rusted nail heads look like the surrounding wood.