It is recommended to apply southern cypress siding over standard sheathing material with maximum stud spacing of 16 inches O.C. (off-center). Where building codes permit, siding may be applied over unsheathed walls. A suitable building or felt paper wind barrier is recommended and must be used where building codes require.

Foam and Foil-Faced Sheathings: Both rigid foam and foil-faced sheathings can be vapor barriers. Rigid foam sheathings, however, offer little or no resistance to sag caused by the weight of the siding on the nails. For application of southern cypress over rigid foam sheathing, use angular threaded ring shank nails long enough to penetrate at least 1 inch into framing members. For example, siding over 1-inch foam requires a 3-inch nail (10d). Note: southern cypress siding applied over foam sheathing may take on a wavy appearance if the siding is compressed by nailing with too much force.

Installed Siding Material Checklist

Nails: Hot dipped galvanized or stainless steel with 1/4 inch head; nails must be long enough to penetrate 1 1/2 inches in studs; ring shank or thread shank nails provide increased holding power and must penetrate studs at least 1 inch; siding nails should have blunt points to reduce splitting of the siding.

Caulking: Use high-grade, non-hardening polyurethane. Do not use latex caulks.

Paint and Stain: Use oil-based primers, paints and stains only. See finishing instructions.

Drip Caps and Flashing: Must be used over doors, windows, masonry, and other types of siding, and siding returns at dormers.

Corner Boards: Must be used at inside and outside corners (see illustrations).