How to Drywall in an Attic - Applying and Repairing
Drywall can be installed either vertically or horizontally. Plan your installation so that the least number of seams are created.
Use this criterion to choose the size of drywall for your project, and plan the application before proceeding. Remember that when two boards butt up against each other at their long edges, both must have a beveled factory edge.
Use a scraping plane or rasp on cut edges to smooth any roughness.
When positioning the drywall panel, align the top of each panel with the ceiling edge or the angle break to assure a clean edge. To raise the panels you can make a foot fulcrum with two pieces of wood. Any gaps should fall close to the floor where a baseboard will cover them. All joints between boards should be positioned to meet over the center of a stud or rafter.
Start a couple of drywall nails at the corners and across the top of the drywall panel before you lift it into place. This way, once the panel is positioned, it will be easier to attach. You will still need another person to hold it in place, though.
The best drywall nails have cupped heads, which make them easier to cover when mudding and taping. Those with barbed shanks increase holding power and reduce "nail popping." Nail along the edge of the panel about every six inches, hammering the nail into the stud. In the middle of the panel, nail about every 12 inches. Check local codes for variance. It is advisable, if the studs are new wood, to double nail in the field.
Hammer each nail until it is forced slightly below the surface of the panel—this is called dimpling. Also, be careful not to ding the edge of the panel when nailing or handling. Dings require extra mudding and finishing work. If you are using drywall screws, be sure you screw them to just below the surface of the panel, but do not break the paper when you do this. If the paper is broken, drive another nail nearby to assure a good hold.
It is advisable to have a special drywall hammer or a cordless electric drywall screw gun for speed and ease of handling. Place nails in adjoining sheets directly across from each other where they meet at a stud. This makes mudding easier. If you miss the stud, pull out the nail or screw and dimple the hole so as to be able to mud and tape over it properly.
Another alternative is to glue the drywall with drywall adhesive. The glue is used in the center of the board with nails used around the edges. Follow the manufacturer's instructions when gluing. The glue avoids seams that need to be taped and finished.
As you apply the drywall, try to leave no gaps between boards more than 1/8 to 1/4 of an inch—smaller if possible.
If required, get your nailing pattern inspected (check local code) before covering with tape and spackling.
Cutting Drywall for Openings
Applying drywall around openings like doors and windows calls for extra care and accurate cutting. Never try to fit around a large opening with just one panel. Work with two pieces about the same size, with a seam that meets in the middle over the opening.
Seams must always meet at a stud, but should never occur at the edge of a door or window. The door opens and closes at this point, and the seam will eventually crack from the movement. Be particularly careful not to damage the board when cutting a notch or corner.
For right angle openings, use a drywall T-square or a chalkline to mark the board for cutting.
Cut the shorter length with a wallboard saw or keyhole saw. Use a utility knife to score the longer cut. Use several fight strokes with the knife to cut into the core. Position the cut over the edge of your work table and snap the panel. Finish by cleanly undercutting the paper on the back side with the utility knife. Always cut with the good side up.
To cut an opening around a window, place the panel in position and mark on the edge of the panel to indicate the top and bottom of the window opening. Measure and record the distance from the top mark to the edge of the window and from the bottom mark to the edge of the window. Use a drywall square to connect the points, and make your cut accordingly.
For smaller openings like outlets, an efficient trick is to outline the opening with lipstick or colored chalk and then fit the panel into place and give it a couple of good whacks over the outlet area. The lipstick will transfer to the back of the panel for a cutting pattern.
Cut this patch out with your keyhole saw. Take care when cutting from the back side of the panel not to tear the paper beyond the patch hole area. Use the utility knife to finish cutting through the paper on the front side of the panel.
Drywalling Angles and Ceilings
Cutting a complex piece of drywall takes a bit of precision and may best be done with a paper or cardboard template. By taping something more flexible than drywall over the space to be covered and marking the dimensions on that, your fit will be more exact.
Ceilings and slants (like attic ceiling-walls) pose a serious problem in the form of gravity. More than one person will be needed to support each drywall panel as it is secured into place unless you use a 2x4 "T" cut to the height of your ceiling, less 3/4 of an inch, with a 3 foot section of 1x4 attached to it as a support.
Drywall screws used with a drywall screw gun are more efficient and convergent here. The pattern for fastening with screws is the same as when using nails—every 6 inches around the edges and 12 inches in the field. Check local codes.
Remember that ceiling pieces should always be installed before wall boards. The wall boards will then serve as added support for the ceiling boards. Angled ceilings may be installed after the walls.
Curves and Odd Spaces:
The easiest way to transfer the exact measurement from the stud system to the drywall is with a paper or cardboard template.
Tape the paper to the stud and use a chalkline snapped down the center of each stud to mark the proper measurements on the paper. Transfer these measurements to the drywall. Cut small triangular slits in the paper and tape over these to the drywall with masking tape.
To compensate for the angle being created, cut the template pieces slightly smaller (cut to the inside of the chalkline) than the actual space defined by the studs.
Use the utility knife to make long cuts and a keyhole saw for the cross cuts. Fasten the drywall to the studs. In these areas, beveled factory edges are not needed between adjoining pieces.
About Tape and Mud
To achieve a smooth finish, all screw and nail heads must be covered with mud and all seams must be covered with tape. Joint compound and vinyl spackling are both referred to as "mud." Vinyl spackling is recommended because of its quick drying time of about one hour or more, depending on the thickness of application. (Allow longer for deeper cracks and crevices.) Conventional joint compound has a drying time of 8 to 24 hours, depending on the thickness of application.
Work from a mud tray to keep any dried pieces and bits of debris out of the can. Cleanliness is very important. Keep the lid on the mud bucket air tight when you are not using it to keep it from drying out. Smooth the top of the mud flat and add ½ inch of water before sealing the can if it will be stored for some time.
Compound can be purchased in 1 or 5 gallon buckets. Unless you are doing a very small job, the 5 gallon bucket is a much better buy. While using, scrape the inside wall of the container often to keep residue from hardening and dropping pieces into the compound.
Drywall tape is available in paper tape, which is pre-creased and can be used on straight seams as well as corner taping. Self-adhesive fiberglass tape can also be purchased, which has the advantage of not needing a coating of mud underneath.
Application of Mud and Tape
Cover all nail dimples, applying the mud flush with the panel. If you are using paper tape, apply the first layer of mud with a 4-inch mud knife. Apply enough mud to the seams for the drywall tape to adhere and to cover the entire seam.
Apply the tape and embed it into the mud. While the mud is still wet, apply a second layer of mud to cover the tape completely. At the same time, draw your blade tightly over the surface to squeeze the mud out from underneath the tape so it is good and flat. Take care not to create any bubbles.
A popular alternative to paper tape is self-adhesive fiberglass or fabric tape. With this type of tape, an undercoat of spackling is unnecessary. Simply apply the tape over the seam and then add a layer of mud over the tape.
Inside corners must be covered with paper tape because the fabric tape will not fold. Again, apply a layer of mud first, covering each side of the corner and then embed the folded tape. Finish smoothing the mud over and around the corner using a special corner knife.
Outside corners require metal corner beads to provide stability and protection to the drywall. Cut them to fit the full height of the corner with tin snips and fasten it in place with nails or screws every six inches. Mud over it like any other seam, feathering the spackling out from the corner. This first coat of mud should be completely dry before you go on to the next. A heater with a fan will cut down the drying time considerably.
Use a knife blade to scrape off any dried chips at the seams and nail head areas. Sand the first coat smooth with an orbital sander or sanding block before applying the next coat of mud. Use 80 to 100 grit sandpaper. You can wipe it down with a large wet sponge in lieu of sanding, but take care not to soak the paper or wash away the spackling.
The second coat of mud needs to be thinned down with a little water and applied with a 6 inch mud knife. Each coat you apply should be thinner than the last. Apply the third coat with a 10 inch mud knife for a smooth finish. Again, sand or sponge smooth after each coat dries. (Only two coats of spackling are necessary for textured finishes.)
Once the final coat has dried and been sanded, use a flashlight to check for blemishes. The light casts a shadow, which makes it easier to see the irregularities. A good smooth finish is essential to a good paint or wallpaper job. Always do a final sanding or sponging before preparing to paint or paper the newly applied drywall.
A primer-sealer undercoat is necessary to seal drywall and unpainted plaster or wallboard compound. Priming also prevents the base wallboard and outline of mudding applications from "showing through" any paint or wall coverings you may apply.
Many primer-sealers are also "sizing," a preferred prerequisite to wallpapering. An oil-based primer is best for bare drywall, but be sure to check with your dealer for special considerations with your chosen wallcovering. See the DoItYourself categories on interior painting and wallpaper.
Use a keyhole saw and utility knife to cut out the damaged portion and clean out broken pieces around the edges of the hole.
Remove a strip of the paper ½ to one inch wide surrounding the perimeter of the hole and then cut a new piece of drywall that is slightly larger than the hole. Carve away the gypsum on the back side of the patch until it fits the hole opening but leaves the paper on the outside of the patch intact. This is called a "hat patch."
Apply compound to the inside and outside edges of the hole and fit the paper "brim" of the hat patch right over the bare gypsum. Now, all you have to do is mud over the hat patch and allow it to dry. With a knife blade, scrape off any dried chips. Lightly sand the patch and then apply another layer of mud. When this layer is dry, scrape it, sand it lightly, and then apply a final thinned-down coat of the spackling.
Remember to sand once again prior to painting or wallpapering. Bare spackling on any wall repairs should always be covered with primer before paint or wall paper.