Chapter 18 Interior Wall and Ceiling Finish
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Explain wall and ceiling covering materials. Describe wallboard cutting, nailing, and adhesive techniques. Illustrate how double layer and predecorated wallboard are applied. Describe the characteristics of gypsum plaster. Explain how gypsum lath and expanded metal lath are applied. Objectives Construction Training School, St. Louis, MO
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Illustrate the use of plaster grounds. Describe plastering methods. Lay out ceiling tile and install furring strips. Describe methods for leveling and installing a suspended ceiling. Estimate quantities of lath, wallboard, and ceiling tiles for a specific interior. Objectives (Cont.)
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Interior Finishing Installation of cover materials to walls and ceilings Starts after mechanical systems and insulation are installed Ceilings can be covered with many of same materials used for walls Wagner
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Requires that studs and ceiling joists be perfectly straight and true Wood framing material must have proper moisture content Preferred by builders because it saves time Drywall Construction
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Handling and Storage Drywall should be delivered a few days before installation It can be transported manually or by machine Stack drywall flat on clean floor in center of largest rooms
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Types, Thicknesses, and Styles Wallboard types –Regular –Type X –Mold-resistant Variety of thicknesses and edge joint designs Drywalling requires some special tools
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Single-Layer Construction Used where economy, fast installation, and fire resistance are needed Methods of arranging drywall sheets –Parallel –Perpendicular
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Measuring Measurements should be taken where wallboard will be installed Use steel tape to take measurements Drywall square can be used to mark square cut line on panel Construction Training School, St. Louis, MO
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Cutting Score face of panel with utility knife Snap core and cut backing paper Portable power tool makes cutting holes in drywall for electrical boxes easier
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Screw Fastening More common for gypsum board than using nails Special screws are used for metal-framed wallboard systems Braces can be used to support large panels for ceiling St. Paul Technical College
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Nail spacing varies depending on materials used For single-layer construction, space nails no farther apart than 7″ on ceilings, 8″ on walls Drive nails straight and true Be careful not to break paper face of board Nail Fastening
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Drywall may be fastened with adhesive that is sold in cartridges Apply continuous bead over frame surface using hand or powered gun Some adhesives have flammable solvents Do not use where open flames are present Adhesive Fastening
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Concealing Joints and Fastener Heads Regular or pressure- sensitive tape is used to conceal and reinforce joints Apply two coats of fast- setting joint compound over tape Stilts are often used to reach high areas Loren LaPointe Drywalling
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Corners Outside corners are reinforced with metal corner bead Reinforcing tape is used at inside corners Bead or tape is concealed with joint compound
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Wide range of finishing materials available –Clear water repellents –Bleaching oils –Stains –Paints For paint, apply priming coat Apply first topcoat of paint within two weeks of applying primer Painting and Maintenance
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Use clean water and follow instructions on bag Mix only what can be used up within working time Adding water later will not prevent setting or increase working time Ready-mixed compound should be used as it comes from container Mixing Compound
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Attaching Drywall to Steel Framing Arrange panels parallel or perpendicular to framing Attach them with 1″ long Type S screws Leading ends must first be attached to open edge of stud or joist flange
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Double-Layer Construction Applications over wood framing ensure strong wall surface –Type X, fire-rated wallboard –Water-resistant backing boards –Sound deadening backing board
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Backing board is applied to framing with staples, nails, or screws Finish layer is laminated to base layer with adhesive or joint compound Finish layers can be applied parallel to base layer or at right angles to it Attaching Layers
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Cut and fit drywall sheets Apply adhesive to entire surface or in strips Trowels and powered devices for applying adhesive are available Strip lamination is frequently used for sidewall panels Temporary bracing may be used to hold panels until bonding takes place Applying Adhesive
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Joints should be taped, nails concealed, and corners finished on wallboard that will receive other covering material If plaster is to be applied, use reinforcing tape and single bedding coat of compound over joints Always use single length of corner bead to extend from floor to ceiling Finishing Double-Layer Wallboard
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Special Backing Used as base for tile in areas where walls are frequently wet Example: Cement board Some backing boards are rigid Others are somewhat flexible National Gypsum Co.
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Working with Cement Board Cement board can be worked with ordinary carpenter’s tools Score and snap panels apart or cut with saw Smooth rough edges with sandpaper Gold Bond Building Products
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Type of gypsum wallboard processed to withstand moisture and high humidity Covering is treated to be mold and mildew resistant Not used under ceramic tile Can be used in other areas of bathroom Mold-Resistant Wallboard
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Veneer Plaster High-strength material applied as coat less than 1/8″ thick Can be applied as one- or two-coat system Special gypsum board is used for base Proper mixing of veneer plaster is important
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Predecorated Wallboard Panels usually applied vertically Can be attached to furring strips, studs, or other solid surfaces Manufacturers recommend both gluing and nailing for 1/4″ panels ABTco, Inc.
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Wallboard on Masonry Walls Can be installed over metal or wood furring strips Can be directly laminated to masonry surface with adhesive Exterior walls must be waterproofed Insulation may be included
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Hardboard Has low moisture- absorption rate Face is often scored to form bead-board pattern Installation methods are similar to those for plywood Masonite Corp.
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Solid Lumber Paneling Makes durable and attractive interior wall surface Several patterns are available Allows boards to adjust to temperature and humidity before installation Western Wood Products Assn.
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Solid Paneling on Angle Diagonal paneling angles in only one direction Chevron paneling has V or inverted V pattern Herringbone paneling alternates angle direction at regular intervals Western Wood Products Assn.
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Be sure solid wood paneling has proper moisture content About 8%–10% for most regions of United States Store paneling in room and allow room air to reach both sides of wood before installation Pro Tip
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Plaster Gypsum plaster provides desirable qualities in wall and ceiling finishes Grounds serve as guides for plasterer Lath is applied to form plaster base Do not discard leftover plaster in sink or toilet National Gypsum
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Plaster Base Common plaster bases –Gypsum lath –Expanded metal lath Plaster can be applied directly to masonry surfaces Insulating fiberboard lath also used as plaster base
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Metal Lath Provides rigid wall surfaces Contains many small openings that allow proper keying of plaster Must be of proper type and weight for support spacing
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Reinforcing Wood frame structures can expect shrinkage May cause plaster to crack around openings Expanded metal lath is often used in key positions to minimize cracking
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Plaster Grounds Usually wood strips as thick as plaster base and plaster Used as gauge for thickness of plaster Window jamb extensions also serve as plaster grounds
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Furring strips usually installed on outside walls Prevents excessive heat loss through walls Carry plaster base materials and provide airspace Blanket insulation can be installed to reduce heat loss Plaster Base on Masonry Walls
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Plastering Materials and Methods Plaster is applied in two or three coats –Scratch coat –Brown coat –Finish coat Plaster that has started to set should be discarded National Gypsum Co.
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Tiles Used on walls, floors, and countertops in bathrooms and kitchens –Ceramic and porcelain –Quarry –Glass –Natural stone Make waterproof, long- wearing, attractive surfaces
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Preparing for Tile Installation Framing under tile floors must support floor, prevent flexing Cement board or other tile backing is used Knife with carbide edge can be used to score cement board
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Do not cut cement board indoors with power saw Cement board contains silica dust that is harmful if inhaled Wear dust mask when cutting cement board Safety Note
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Ceiling Tile Can be installed over strips or any smooth, continuous surface Various sizes and patterns are available Overlapping tongue-and- groove edge provides flange to receive staples
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Furring Should be nailed to ceiling joists Make sure strips will be centered over tile joints Make sure faces of strips are level with each other Large pipes or ducts that project below ceiling joists should be boxed in
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Adhering Ceiling Tile Tiles can be attached with stapler Staples should be at least 9/16″ long Adhesive can be used for installing ceiling tiles Keep your hands clean while handling tiles Duo-Fast Corp.
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Metal Track System Long metal tracks may be used rather than wood furring strips Tracks are nailed or screwed to old ceiling or to joists Clips snapped into track slides over tile lip Armstrong World Industries, Inc.
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Suspended Ceilings Have metal framework that supports tiles or panels Channels of suspension system are concealed by ceiling panels Panels have tongue-and- groove joints Spectra-Physics Laserplane, Inc.
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Find total number of square feet of wall or ceiling area Disregard regular-size door and window openings Subtract area of larger openings, such as window walls or picture windows Ceiling area is usually same as floor area Estimating Materials
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Specify length of sheets Plan to use longest practical sheets Divide total length of walls by width of sheets to find sheets needed Estimate each room separately Consult tables for estimates of joint compound, adhesives, and nails Sheet Materials
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Figure area (square footage) to be covered Round off any fractional parts of foot in width and length to next larger full unit Add extra units to balance installation pattern with border tile along each wall Estimating Ceiling Tile
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Construction Careers Plasterers Apply materials to form smooth, hard finishes on interior walls Most work for small-to- medium-sized specialty contractors Stucco masons are in related trade Most plasterers and stucco masons learn their skills on the job Revel Pix LLC/iStock/Thinkstock
Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Construction Careers Drywall Installers Measure, cut, and install drywall sheet for walls and ceilings Ceiling tile installers and lathers are in related occupations Most drywall installers learn their skills on the job Christina Richards/iStock/Thinkstock