Chapter 13 Exterior Wall Finish
Cornice • Definition: the overhang of a roof at the eave. • Includes the fascia board, a soffit, and any moldings. • Provides a finished connection between wall and roof.
Rake • Definition: Part of a roof that overhangs a gable. • Projecting roof boards support trim for boxed rake section. • Roof framing is extended when the rake projects a considerable distance.
Framing a Cornice • Install ledger strip along wall • Mark points with level that match up with bottem edges of rafters • Nail on the ledger strip • Cut the lookouts • Toenail one end of the lookout to the ledger and nail the other end to the overhang of the rafter • Apply the soffit
Prefabricated Cornice Materials • Various systems available • Ex. 3/8” laminated wood-fiber panels • Fasten with 4d rust-resistant nails spaced about 6” along edges and intermediate supports • Nail main supports first and then along edges • Always leave space for expansion
Metal Soffit Material • Provided in rolls and sheets in several widths • Aluminum systems are suggested • Widths vary from 12 – 48” • Edges are held in runner guides that are attached to fascia and walls • Consists of 3 basic units: • Wall hanger strips (frieze strips) • Soffit panels • Fascia covers
Hanging Metal Soffit • Snap a chalk line along the side wall, level with the bottom edge of the fascia board • Attach metal U-shaped wall hanger strip along line • Attach hanger strip flush with the bottom fascia or nail the metal soffit panels to the bottom of the fascia board as panels are installed • Insert the panels • Cut metal or vinyl fascia cover to fit and install it
Horizontal wood siding • One of the most common materials • Usually applied over a base of sheathing and a house wrap • Bevel siding is most common • Available in various widths • Made by sawing plain surface boards at an angle
Channel Rustic siding has shiplap type joints Drop siding usually has tongue-and-groove joints heavier, has more structural strength Wood Siding (Cont.)
Wall Sheathing and Flashing • Siding can be applied over various sheathing materials. • Solid wood, plywood, or nail-base fiberboard is nailed directly to the material at about 24” intervals. • Gypsum board and regular fiberboard sheathing cannot be used as a nail base and the siding should be nailed through the sheathing and into the frame.
Sheathing Substitutes • An insulation board of rigid polystyrene (13-17) can take the place of sheathing and sheathing paper • Metal flashings must be applied (13-18)
Installing Horizontal Siding(Preparing a Story Pole) • Lay out the distance from soffit to 1” below top of foundation. • Divide distance into spaces equal to the width of the siding minus the lap. • Adjust the lap allowance so spaces are equal. • Mark position of top of each siding board on the story pole when layout is complete.
Installing Horizontal Siding(Continued) • Start application of bevel siding by first nailing a strip along the foundation line equal to the thin edge of the siding. • Apply the first piece. • Allow the butt edge to extend below the strip to form a drip edge. • Inside corners can be formed with a square length of wood or metal corners. Outer corners are usually made of metal. Install. • After the corner boards are in place, fit the siding tightly against them. • Wood siding can be given a coat of water-repellent preservative before it is installed, or it can be brushed on after installation
Nailing • To fasten siding, noncorrosive nails are recommended. • Horizontal siding should be face-nailed to each stud. • For narrow siding, the nail is generally placed about ½” above the butt edge. • Different types of wood siding require different nailing patterns. (Fig. 13-26)
Estimating Siding • Increase the footage to make up for the difference between nominal and finished sizes. • The net square footage of the wall surface to be covered should be multiplied by the factor in the chart to your left.
Vertical Siding • Commonly used to set off entrances or gable ends. Also for main wall areas. • May be plain-surfaced matched boards, pattern matched boards, or square-edge boards covered at the joint with a batten strip. • Made from solid lumber, should be no more than 8” wide.
Wood Shingles • Sometimes used for wall covering, and a large selection of types is available. • Very durable and can be applied in various ways to provide a variety of architectural effects. • Most shingles are made in random widths • Shingles in side walls are frequently laid in double coursing • Double coursing- when you use a lower grade shingle under the shingle exposed to the weather. The exposed single butt extends about ½” below the butt of the under course.
Single Coursing of Side Walls • Similar to roof application—difference is in the exposures employed. • Present less weather-resistance problems than roofs. • Weather exposure of shingles should never be greater than half the length of the shingle, minus ½”. • Should have concealed nailing.
Shingle and Shake Panels • Shingles and shakes for side wall application are available in panel form. • Usually western red cedar. • Standard size = 8’ • Applied by following the same basic precaution and procedures described for regular shingles. However, takes less time.
Uses Provides a vertical treatment to gable ends. Provides emphasis as fill-in panels above and below windows. Establish a continuous decorative band at various levels along an entire wall. Must be made from exterior type plywood. Most common- Douglas fir Panel sizes are 48” wide by 8’,9’,10’ long Because large sheets of plywood and hardboard siding provide tight, draft-free wall construction, it is important to have an effective vapor barrier. This should be between the insulation and the warm surface of the wall. Plywood Siding
Aluminum Siding • Factory finished with baked on enamel and provides appearance that resembles wood siding • Offers low maintenance costs • For use on new or existing construction • Can be applied over structurally sound surfaces
Vinyl Siding • Definition: a rigid polyvinyl chloride compound that is tough and durable • Installed with a backing or insulation board • Panels have interlocking joints that are waterproof • No movement during expansion or contraction
Installing Vinyl Siding and Soffits(Preparing the old siding) • Nail loose boards & trim-replace rotted boards • Remove old caulk from windows and doors • Remove downspouts, lighting fixtures and moldings that interfere with new siding • Tie back shrubs and trees that can be damaged
Installing Vinyl Siding and Soffits(Continued) • Allow a ¼” expansion gap where siding meets accessories when cutting • Do not drive nails tight against the siding, leave a gap of about 1/8” • See fig. 13-61 for Installing Starter Strips and Trim
Installing Siding Panels • The first siding panel snaps into the bottom of the starter strip. • Work toward the front of the building, finishing each side before starting the next • Always cover largest areas first; smaller panels can be used up on the smaller surfaces, such as dormers • Overlap each panel 1”, face butt edge away from the main traffic areas.
Stucco • Base consists of wood sheathing, sheathing paper, and metal lath • Apply second coat when first is dry to give a smoother “pebbled” finish • Typically, the finished stucco wall is 7/8” thick
Definition: also called “synthetic stucco” and are similar in appearance to stucco. Available either as polymer-based (soft-coat systems, typically 1/8” thin) or polymer-modified (hard-coat systems, about ¼” and are mechanically attached.) Installation: Can be installed over wood, concrete, concrete block, and other substrates. Base coat should be at least 3/16” thick, apply two layers Mesh is installed with laps offset from edges of openings, joint, grooves, and corners. If base coat is required before applying the finish coat, it should e applied in 2 thin layers (1/16” each) Exterior Insulation Finish Systems
Brick or Stone Veneer • Veneer Wall- masonry wall, a wall framed in wood or metal to which stone, brick, or even concrete bock—are attached rather than siding
Trowel is the most used tool in the mason’s tool kit. Toe (or point) – pointed end of the trowel Heel – the wide end of the trowel Mason’s level is also an important tool. Has both vertical and horizontal vials, read from either side. Aluminum or wood with metal edges. Two rules, 6’ folding with a 6” sliding scale the other a 10’ steel tape Jointers or jointing tools are used to compress A brick hammer is used to drive nails, strike chisels, and break or chip masonry units Tools
Bricks are structural units made to several sizes from clay or shale. Material mixed with water then dried in large kilns Building or Common Brick A strong general purpose brick intended for use where strength is more important than appearance Three grades: SW grade resists freezing MW grade is used where there may be exposure to below freezing temp. but in dry locations NW grade is used to back up interior masonry Masonry Materials
Facing – used where appearance is important Three types: FBX is for general use in exposed interior or exterior walls or partitions. Color and size are uniform FBS is for general use in exposed exterior and interior walls and partitions where wider color variations and sizes are permitted FBA is used to produce architectural effects produced by lack of uniformity in size, color, and texture Mortar is mostly portland cement with the addition of hydrated lime and sand. Designed to bond bricks and block into a strong, waterproof wall. Masonry Materials (Continued)
Blinds and Shutters • Installed at sides of window units • Consist of frame assemblies with solid panes or louvers • Used to protect the glass, provide security when locked. Serves decorative purpose now • Attached to exterior wall with screws or other fasteners