Locate and drill bolt holes

Anchor bolts sometimes come out of the foundation at odd angles. You can straighten bent bolts with a length of pipe, as shown in the photo at left. Then set long, straight, pressure-treated sill boards in place for mark­ing and drilling. You can use a square and a tape measure to lay out the bolt hole locations

ІІІІШІІІІШШШШШШШШШІІШІШШШМШІМШІІІШІІІІІІШІІІШШІІІШІІШШШШШШШШІІІІМШШШШШІІШШШШІІІШШШШШШІІІІІІІІШШШШІМШШІІІ

POSITIONING SILLS ON THE FOUNDATION

Siding without sheathing

Nut and washer

Sill

Anchor bolt

Concrete foundation

ABC

Sill plates can be set flush with the edge of the foundation (A) and the siding nailed directly to the walls. When sheathing the house frame with OSB or plywood, though, hold in the sill plates 1/2 in. (B). When using rigid foam to insulate a basement or a crawl space (C), position the plates so that the outside face of the sheathing is in plane with the outside face of the foam.

A bolt marker comes in handy. Use a bolt marker to transfer the bolt locations to the sills so you can drill the bolt holes accurately. [Photo by Don Charles Blom]

An electric drill is great for boring holes. Use a spade bit in an electric drill to bore bolt holes through a wood sill.

MAKING A BOLT-HOLE MARKER

Select an 18-in. by 11/2-in. by 1/8-in. metal plate strap. Cut a notch in one end of the strap so that it will fit around a 1/2-in. or 5/8-in. bolt. From the center of the notch, measure back 31/2 in. for a 2×4 plate and 51/2 in. for a 2×6 plate. Drill holes at those points and insert 3/16-in. by 3/4-in. stove bolts. Put a bend in the plate strap to make it easier to use.

A bolt-hole marker makes it easy to transfer the bolt location to the sill in preparation for drilling a hole.

z/2-in. bolts. For 5/8-in. bolts, use a 3/4-in. bit.

on the sills, but it’s a lot faster to mark the hole locations with a bolt marker. You can make a bolt marker or buy a ready-made ver­sion (see the illustration on p. 59 and Resources on p. 279). To use this layout tool, place each plate directly on the inside of the chalkline.

Once the bolt locations are marked, set the sill plates on blocks of wood or sawhorses and drill the holes. Use a 5/8-in. bit to make holes for

Install sill seal and termite shields

Sweep the foundation clean of debris, then put down a layer of sill seal insulation where the sills will be located (see the photo on the facing page). Sill seal does just what its name says. As an alter­native, you can run two heavy beads of silicone caulk between the sill plates and the foundation. This also prevents cold air leaks between the foundation and the sill. In areas where termite infestation is a possibility, you’ll also need to lay down a termite shield over the foundation bolts and under the sill. As shown in the illustrations on p. 50, the shield edges must extend beyond the foundation (including the foundation insulation) and the sill.

Place the sills over the bolts, put on the washers and nuts, and tighten the nuts with a crescent wrench, taking care to keep the inside edge of the sill on its layout. (Note: When work­ing on a slab, drill holes in the plates but leave them unbolted until after the wall is raised— see Chapter 4 for details.) Codes in earthquake and high-wind areas often require the use of larger washers (galvanized, /4 in. thick, and 2 in. square). These larger washers help secure the mudsill and keep it from splitting when under pressure from lateral forces.

If the measuring work you did at the begin­ning of this step told you that parts of the foun­dation were out of level, you can expect the sills to be that way, too. To correct slight discrepan­cies (up to /4 in. or so), you can insert pressure- treated shims underneath the sills. For larger errors, it’s best to call in a concrete contractor.