Tempo:
Exterior Trim and Millwork
Exterior trim and millwork include window and door trim, soffits, rake, gable and fascia trim that are cut and installed on site and other accessories such as louvers and shutters that are usually shop-manufactured. Trim should be low maintenance, resistant to weathering, workable and dimensionally stable (low tendency to warp, shrink or contract and expand). Prefinished sheet metal is now widely used because it is impermeable to water and can maintain its finish for many years without having to be repainted. Correct detailing and sealing are a must to prevent water from running behind the metal trim. When wood trim is used, seal the end joints or mitres of lumber exposed to moisture. Nails or screws used for fastening trim should be corrosion-resistant, aluminum, galvanized or stainless steel. They must be compatible with the metal trim to avoid galvanic reaction
between dissimilar metals, such as aluminum and steel. If finishing nails are used, they must be countersunk and then sealed after the prime coat is applied to prevent rust stains at nail heads. When the siding is prefinished, matching pre-painted nails may be used.
EAVE PROJECTION The eave overhang gives some protection to the wall. Soffits are usually clad with prefinished perforated metal or vinyl panels (Figure 136). These are low maintenance and provide ample area for venting roof spaces without permitting insects to enter the space. A narrow eave projection is sometimes used on roofs with steep slopes. Soffits should not be used to vent rainscreen wall spaces. Plywood was once commonly used for soffits and still is at times. Apply 6 mm (1⁄4 in.) sanded plywood nailed at 150 mm (6 in.) on centre along the edges and 300 mm (12 in.)
Exterior trim and millwork include window and door trim, soffits, rake, gable and fascia trim that are cut and installed on site and other accessories such as louvers and shutters that are usually shop-manufactured. Trim should be low maintenance, resistant to weathering, workable and dimensionally stable (low tendency to warp, shrink or contract and expand). Prefinished sheet metal is now widely used because it is impermeable to water and can maintain its finish for many years without having to be repainted. Correct detailing and sealing are a must to prevent water from running behind the metal trim. When wood trim is used, seal the end joints or mitres of lumber exposed to moisture. Nails or screws used for fastening trim should be corrosion-resistant, aluminum, galvanized or stainless steel. They must be compatible with the metal trim to avoid galvanic reaction
between dissimilar metals, such as aluminum and steel. If finishing nails are used, they must be countersunk and then sealed after the prime coat is applied to prevent rust stains at nail heads. When the siding is prefinished, matching pre-painted nails may be used.
EAVE PROJECTION The eave overhang gives some protection to the wall. Soffits are usually clad with prefinished perforated metal or vinyl panels (Figure 136). These are low maintenance and provide ample area for venting roof spaces without permitting insects to enter the space. A narrow eave projection is sometimes used on roofs with steep slopes. Soffits should not be used to vent rainscreen wall spaces. Plywood was once commonly used for soffits and still is at times. Apply 6 mm (1⁄4 in.) sanded plywood nailed at 150 mm (6 in.) on centre along the edges and 300 mm (12 in.)
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