The inside story on the stuff that makes up your walls
Published 3:29 pm Tuesday, April 17, 2012
Sheetrock, wallboard, plasterboard, gyp-board and drywall are the words used to describe the wall and ceiling finish material used in most modern homes.
Here, for your edification, are a few fun facts about its history and how to install it.
According to Wikipedia, the predecessor to modern-day drywall was known as “Sackett Board.” It was invented in 1894, and was made by layering plaster within plies of wool-felt paper.
About 25 years later, drywall took a giant leap forward with the introduction of gypsum board. Gypsum board came with wrapped edges and had paper facings. Installation was improved because it was thicker and each sheet covered more area. It was quick and easy to install, incredibly durable and required only simple repairs when damaged.
Drywall was, and still is, used to improve fire resistance at walls and ceilings, containing the spread of fire so people can evacuate more safely in an emergency.
When you ask for drywall, the store clerk will always offer regular unrated material that is typically used to cover ceilings and interior walls. Even standard drywall has a fire resistant property. The following table denotes the various types of rated drywall and what each is used for:
Fire rated: Contains a special mixture of ingredients that resist fire much longer than regular drywall.
Impact resistant: Commonly used in schools. Ingredients make this drywall much stronger. Thicker paper is used to reduce surface damage.
Moisture resistant: Water-resistant paper covers the standard core. Commonly used in wet areas.
Sound resistant: Used to reduce the transmission of sound between walls. such as in multi-unit housing.
Lead lined: Most commonly used in X-ray labs and other areas subject to radiation.
Flexible: Quarter-inch thick drywall is moistened with water and used to wrap around surfaces. Once dry, the drywall holds its shape.
Plaster board: Used as a backing for a thin coat of plaster.
Button board: Each sheet contains myriad small holes spaced a few inches apart in every direction. It is used as the base for modern-day plastering and replaces the wooden lath of yesteryear.
Drywall installation involves only two steps: hanging and finishing. The first step in hanging is to cut the drywall to the needed size. Use a 4-foot-long aluminum T-square for marking and cutting. Measure the length/width needed and make a pencil mark as a guide.
Continuing to use the T-square as a guide, use a utility knife (razor knife) to score the drywall. Once scored the drywall is quickly folded away from the scored side breaking the drywall. Cutting the paper on the other side completes the process.
If this cutting procedure seems a bit difficult, a course-tooth saw may instead be used.
Once cut to size, the drywall is held firmly against joist or studs and attached with screws or nails. We prefer screws. They hold better and can easily be removed in the event of a mistake.
In either case, although the head of the fastener must be slightly countersunk, the fastener is not allowed to penetrate the paper surface. During a nailing (screw) inspection, paper torn by a fastener does not count toward the total fasteners required per sheet.
Each drywall installation requires a different and specific fastening pattern. Check with your local building official for the one that applies to your installation.
Finally, tape, sand and finish the drywall. This involves using a wide putty knife and joint compound to fill all fastener recesses. Joint compound is also used as an adhesive to affix joint tape to all seams. Then, a minimum of three layers of joint compound are troweled onto the taped seams, covering them and feathering out the lump created by the joint tape.
Each layer of compound is finer and smoother than the previous coat. An experienced finisher can perform the entire process without using sandpaper until the final coat. We DIYers usually are forced to sand every coat.
Caution: Be sure never to sand the joint tape.The next coat will be a mess wherever this occurs.
Keep in mind that at least a day of drying is required between each coat.
Deck finish
We are often asked to recommend a deck finishing routine that will ensure the longest-lasting result. Whether the material is redwood, cedar or pressure treated lumber; the following steps will ensure the longest-lasting finish:
• First, mix a cup of powdered laundry detergent into a gallon of water.
• Wet the deck with a garden hose, then spray on the detergent mixture with a pump garden sprayer.
• Scrub the deck thoroughly with a bristle brush and rinse with water.
• While the rinsed deck is wet, sprinkle on oxalic acid powder (skip this step for pressure treated lumber).
• Scrub until wood is bright, then pressure wash to remove the wood bleach (skip this step for pressure treated lumber).
• Wait several days in warm weather for the decking to completely dry out.
• Then, use a high-quality heavily pigmented deck stain, making absolutely sure that the finish doesn’t puddle during application.
A heavily pigmented oil stain finish should last for several years. Whatever you do, don’t use paint. It will sometimes last a little longer than stain, but it will eventually peel and chip. And when it does, it will be 10 times more difficult to refinish.
For tips from James and Morris Carey, go to www.onthehouse.com or call the listener hot line, 800-737-2474, ext. 59. The Careys are also on KRKO (1380-AM) from 6 to 10 a.m. every Saturday.
