Estimating the amount of gypsum board to be used on a job is done by measuring the length and height of each wall to determine square footage. Amounts for large openings such as doors and windows can be subtracted from the square footage. The total square footage is adjusted to the size of panel to determine the number of panels. For example, 600 square feet of space could be covered with 19 panels that are 4 feet x 8 feet, or 15 panels that are 4 feet x 10 feet, or 13 panels that are 4 feet x 12 feet. The websites listed in the resources section provide calculators for gypsum board panels, fasteners, joint compound, and tape. To estimate the cost of installing gypsum board, calculate the amount of material needed and find its cost. Add 100 percent of the cost for hanging the drywall, and another 100 percent for finishing the drywall. For example, if the cost of material is $980, add another $980 for hanging it and another $980 for finishing it. installation methods Gypsum Plaster on Lath Lath is a perforated surface that serves as a base for plaster coats on walls. In older buildings it consisted of narrow wood strips, about 2 inches wide, nailed horizontally to wood studs or furring strips. After 1940, lath was made of wire mesh, galvanized to withstand the moisture in the plaster. Another type of lath is called plaster board, which is gypsum board perforated and attached to the studs in horizontal strips. Gypsum plaster is normally applied as a three-coat process, with each coat setting until partially dry. Finish coat (d) 1. The base coat is called the scratch coat for installation because it must be cross-raked while wet. The raking or scratching is done to form grooves to help the next coat to bond with it. When applied to metal lath, the base coat will have fibers in it to help it hang on to the metal and not be squeezed through the lath. For smoother types of lath (clay tile, concrete masonry, or gypsum), fiber is not needed in the base coat. 2. The next coat is called the brown coat. The brown coat is used to level the surface and prepare it for the finish coat. It may take several applications to achieve a level surface. 3. The finish coat is a smoother texture and is the last coat of plaster applied.
If gypsum plaster is applied as a two-coat process, the brown coat becomes the base coat. The second coat is the finish coat. Veneer plaster can be applied over gypsum board, usually blue board, on conventionally framed walls.
Gypsum Board over Framing Gypsum board is installed on the ceiling before walls. Screws are used to attach drywall to the ceiling because nails could slip out with gravity. The wall gypsum board should fit tightly against the ceiling board. It can be applied to either wood or metal wall studs, either horizontally or vertically, starting at a corner. When applied horizontally, the panels are started at the top of the wall. Panel seams are staggered and not placed directly above or under a window. Drywall can be attached with either nails or screws. Whereas nails could back out and loosen the drywall, screws will stay in place. The most common method in residential construction is to attach one layer of 1/2-inch drywall to each side of a wood stud wall. When screws are used, the drywall is attached with 1%-inch bugle head screws, long enough to go through the gypsum board Decorating Gallery 6.8 Residential Construction. In residential construction half-inch gypsum board is attached to each side of a 2 X 4 wood stud.
Decorating Gallery 6.10 Cut-Outs. Joints of the gypsum board have been taped and bedded with joint compound. The rectangular cut-outs are for electrical outlets above a kitchen counter. and into the wood studs (type W screws), or 1^-inch long screws for metal studs (type S screws). Panels should overlap at corners. Metal corner bead will be nailed into the studs to reinforce corner joints.
10 Home Decor Ideas For Apartments Photos
Click to Photo for Next Images of 10 Home Decor Ideas For Apartments
There are regional differences in the finishing of gypsum board walls. In the Northeast and Southeast, a smooth plaster finish is normal. It is achieved by applying thin skim coats of plaster over the entire gypsum board wall. The plaster finish is extremely smooth, and it is labor intensive, making it costly, but it does not need to dry between coats, making it a quick procedure.
In the Midwest and West, a taped and bedded finish is normal. This involves applying paper tape to joints and joint compound over the tape. First, all panel joints are covered with a coat of thinned joint compound using a 5-inch wide finishing knife. Paper tape is pressed into the wet joint compound, and more joint compound is applied over the tape. Joint compound is also applied to cover screw heads. The first coat is allowed to dry overnight.
Decorating Gallery 6.11 Orange Peel. A common texture for finish coat joint compound over gypsum board is a splatter pattern called orange peel. It is created by spraying the finish on the wall and leaving the small splatter pattern that resembles an orange.
Decorating Gallery 6.12 Knock Down. A common texture for finish coat joint compound over gypsum board is called knock down. It is created by spraying the finish on the wall and scraping the top with a trowel, thus knocking the top down.The second coat starts with scraping off lumps of dried joint compound. Wet joint compound is applied to the taped joints and screw heads with an 8-inch wide knife. The joint compound is spread a few inches past the tape to feather or gradually level it into the gypsum board. The second coat is allowed to dry overnight.The third coat starts with scraping off lumps of dried joint compound and lightly sanding it to a smooth surface. The third coat is applied with a 10-inch wide knife. This will be feathered 2 inches beyond the second coat. When the third coat is dry, minimal imperfections in the surface can be smoothed with a damp sponge. This type of preparation does not cover the gypsum board completely and is not perfectly smooth. It is intended for a sprayed-on texture to be applied on top, giving a three-dimensional quality. The texture can be sprayed in various patterns.
Decorating Gallery 6.13 Stipple. A common texture for commercial projects is stipple. The texture is applied as a spray over gypsum board. It is more uniform than orange peel or knock down.