Definition: The installation of cover materials to walls and ceilings Prerequisites to Construction: Utilities, heating, and insulation are installed Exterior doors and windows must be hung and installed. Interior finishing
Gypsum wallboard (drywall) • Def: • A laminated material with a gypsum core and paper covering on either side. • Has fireproof core • Variety of thickness, shown on right, and lengths (4’ x 8’, 7’, 9’, 10’, 12’, and 14’ • Also requires special tools (next slide):
Gypsum wallboard for plaster veneering • This is a base of gypsum board • Usually ½” thick • It’s applied as a backing for a thin coat of plaster
Predecorated gypsum paneling • This is the same as gypsum wallboard. • The difference: • Decorative vinyl finishes have been applied and edges have received special treatment so no other finish work is needed.
Plywood and particleboard • Picture to the right is fabricated in 4’ widths. • Lengths: 7, 8, 9, and 10’ • Prefinished in a variety of colors and patterns
Hardboard and fiberboard • These are produced from wood fibers in sizes and thicknesses similar to plywood. • The face finish is simulated to look like wood. • Variations of fiber board are used as ceiling coverings.
Solid wood paneling • These are boards or pieces of solid wood. • Widths: Vary from 2 to 12” • Thicknesses: Either 1” or 2” • Lengths: Vary from 4 to 10’ • Faces may be rough-sawed, plain, or molded in a variety of patterns.
The most popular wall covering. It is made of powdered gypsum to which other materials are added to improve drying time. A plastered wall system includes: A base support, such as metal or gypsum lath Coats of wet plater Plaster
Cement board • Definition: • A versatile fiber-reinforced cement panel material that is used as a base (underlayment) for finishing materials used on walls, floors, and countertops. • Fireproof, & water and impact resistant
Special Finishes • These include a variety of products and materials: • Brick • Stone • Glazed Tile • Plastic Tile • Plastic Laminates • Often found in kitchens and bathrooms
Ceilings can be covered with many of the same materials used for walls. • Composition tiles are especially suitable because they are easy to install.
Drywall Construction • Drywall materials, such as gypsum wallboard, (shown on left) are the most common coverings used in modern construction b/c: • It saves time • Dries faster than regular plaster
Method One: Parallel Long edges of panels run in the same direction as studs and joists. Method Two: Perpendicular Long edges of panels are at right angles to studs and joists. Generally more prefered method. Single Layer Construction* Cover ceiling first, then walls.
In either method, vertical wall joints must fall over and center on studs. • Both parallel and perpendicular are shown to the right • Carpenter will use whichever method has fewer joints.
Measuring and Cutting • Score face with sharp knife pulled along straight edge, cut should penetrate the paper and enter the gypsum core • Support main section of sheet close to scored line • Snap the core by pressing downward sharply on overhang.
4. Support the cutoff with other hand 5. Score the backing paper, as shown on right, and snap the cutoff upward 6. The cut can be smoothed with file or sandpaper
Nails and Screws • For single layer const., nails are spaced no further than 7” (ceiling) and 8” (wall). • Keep 3/8” from ends and edges • (On right) drywall fasteners
Walls Wallboard must be drawn tightly Start nailing at abutting edge Nail the field(area between edges) first Drive nails straight Ceilings Double nailing method of attachment ensures firm contact with framing Nails in field of board should be spaced 12” on center After panel is secured, another nail is driven approx. 2” from first
Adhesive Fastening • Produce a sturdier wall that is more resistant to impact sounds • Some have flammable solvents • Application: • Apply continuous bead to the center of all studs, joists, or furring. • Should be ¼ to 3/8” wide • Use temporary nailing or bracing to ensure full contact of the wallboard.
Joint & Fastener Concealment • Apply a bedding coat of compound into the depression formed by the tapered edges of board over all butt joints • Center reinforcing tape over joint and smooth out. • Press tape by drawing 5-6” knife along joint with pressure • Apply skim coat over tape. • Apply second coat over tape. • Feather edges and apply third coat. • Sand if necessary.
Corners • Outside corners are reinforced with a metal corner bead. • Fasten by nailing into wallboard and frame • Conceal with joint compound • Internal corners • Coat joint compound to both sides • Fold tape along center and smooth
Double Layer Construction • Also called two-ply • Double layer wallboard apps. over wood framing • Base can be drywall or backing board • A gyp. board with a gray liner paper on both sides
Attaching the Layers • Base layers are applied to framing with staples, nails, or screws • The finish layer is laminated to base layer with an adhesive or compound • Joints should be offset at least 10” from the joints of base layer • Adhesive is usually applied to entire surface
Boards • Cement board • Manufactured from a slurry of portland cement reinforced with polymer-coated fiberglass mesh embedde3d in both sides. • Rigid or flexible • Moisture Resistant (MR) Wallboard • Plywood processed to withstand the effects of moisture and high humidity • light green facing • can be used as base under ceramic tile and other nonabsorbent finishing materials
Veneer Plaster • A high-strength material applied as a coat less than 1/8” thick • Dries rapidly • one- or two- coat application • Predecorated Wallboard • Usually applied vertically • Walls must be dry before installation • Use of adhesive to bond panels is common
Wallboard on Masonry Walls • Two methods of preparing masonry walls for interior finish: • (top) Wallboard can be attached to metal furring channels. Rigid insulation is used • (bottom) Wood furring strips and blanket insulation
Installing Plywood • Before, panels should be adjusted to room temp. and humidity • Plan layout, begin at corner • Cut upward against the panel face • Attach directly to wall studs with nails or adhesives • Recommended use: ¼” plywood over ½” gypsum wallboard base
Plaster • Qualities: • Beauty, durability, economy, fire protection, structural rigidity, highly adaptive to shapes, and sound resistance • made from gypsum
Plaster Base • Sheet materials and metal lath • Plaster base materials: A. Gypsum lath B. Insulating fiberboard lath C. Perforated gyp. Lath D. Expanded metal lath
Plaster Materials & Methods • Three-coat work • Scratch coat • Applied directly to plaster base • It is cross-raked after having stiffened • Brown coat • Applied and leveled with the grounds and screeds. A long flat tool called and darby and rod are used • Finish coat • Applied when third coat is somewhat dry • Two-coat work • Scratch coat and brown coat are applied almost at the same time
Ceiling Tile • Can be installed over engineered metal strips, wood furring strips, solid plaster, drywall, or smooth continuous surfaces • Many materials can be used • Standard size is 12”X12”
Estimating Materials • Determining Area of Rooms • Ceiling area is usually the same as floor area • Multiply length times width • Wall area • add all the wall lengths together and multiply by the wall height • Sheet Materials • Always plan to use the longest practical sheet. • Divide total length of walls by the width of sheets to find the number of sheets needed • Estimate each room separately
Estimated Solid Paneling • Based on nominal and unfinished size • Calculate the square footage of the wall to be covered then multiply by the various factors taken from lumber tables: • For 1x6 tongue and groove boards, use 1.17 • For 1x8 tongue and groove boards, use 1.16 • On standard vertical applications, add 5% for waste
Gypsum Lath • Produced in smaller sections than full sheets • Figure the area of the ceiling and add to this the area of the walls (length of walls x height) • Prices are normally based on square yards • Ceiling tile are estimated by figuring the area to be covered (square footage) • Round up