Wednesday, January 26, 2011

How-To: Drywall Installation

HANGING THE CEILING
The first thing to hang is the ceiling. Keep in mind that there is no such thing as a perfectly square house, so your drywall won’t fit exactly square to the framework. Cut it to it as well as possible. When hanging the walls later it will fill up 1/2 inch of ceiling space. Any big spaces will need strips of drywall cut and nailed into place.

MARKING THE CEILING JOISTS
Before hanging the ceiling, mark the ceiling joists throughout the house. When you hold a sheet of drywall against the ceiling, you are unable to see the joists to which you will nail it. The joists rest on a horizontal board called the top plate. If you draw a line on the top plate directly beneath the center of the joist, you will be able to see where to nail. This must be done throughout the house, including the closets. Figure 2-1 shows ceiling joists and where to mark them.

CUTTING THE DRYWALL
After marking the ceiling joists, place your benches in one of the back rooms.


FIGURE 2-1

will not be as much drywall in the way when you get to the front. The drywall will be hung in the opposite direction that the joists run. Place the bench along the outside wall about two feet away from the end. If you do this, you will be under the center of the board when you are standing on the bench.

When you step up onto your bench, have your helper take the end of the tape measure and hold it against the top plate of the wall. You take the other end of the tape and stretch it to the last joist that a twelve-foot sheet of drywall will span.

Read the measurement at the exact center of that joist. Step down and go to the stack of drywall. Hook the end of your tape on the end of a sheet of drywall and pull the tape across the board, placing a mark at the correct length. Take a T-square and put it on the drywall with the edge touching this mark. Hold the T-square tight to the board by putting your toe on the bottom and your knee in the middle of the T-square. Hold the top of the T-square with one hand and score down the side of the T-square with your utility knife. Remove the T-square and bend the board back at the score line. Go around to the back side of the board and score along the groove made when it was bent back. Bend it again and it will break off. Set the excess aside to use later. Figure 2-2 shows how to cut the board. Rasp the end of the board so that it will be smooth. If you have any openings to cut out of the drywall, measure and cut them now. Do not draw the lines for a cutout until the board is cut to the right length.



Cutting Out Openings in the Drywall
To cut out a round hole in the drywall, you must measure from the outside wall to the middle of the hole. Then you must measure from the bottom of the upper board to the middle of the hole. Connect the two points on the drywall and use a circle cutter to score around it. Always allow an extra 1/4 inch. For example, if the diameter of a receptacle is four inches, the opening should be 4 1/4 inches. To cut a rectangular opening in the drywall, you must measure all four sides. After the lines are drawn on the board, use a keyhole saw to cut out the opening. If you put the point of the saw against the board and push against it, the saw will push through the board and you can start sawing from there.

DRAWING THE CENTER LINE
After the drywall is cut and the openings are cut out, draw a line along the center of the board. You will use this line as a guide for nail placement. One way to draw this line is to place a T-square on the drywall. Hold a pencil against the T-square at the 24-inch mark. While holding the pencil tight to the square, slowly slide the T-square across the board. A better way to draw this line is to use a tape measure as a guide. With one hand, hold the pencil at the end of the tape, placing the pencil on the 24-inch mark on the drywall. Hold the tape in the other hand, resting that hand on top of the board. Stretch the tape taut and slide your hands across the board, keeping your hands parallel to each other. This method takes practice, but it is worth learning. It is much faster than using the T-square. Figure 2-3 shows where to draw the line and where to place each set of nails.

HOW TO HANG DRYWALL ON A CEILING
When hanging drywall on a ceiling, you will use a special method of nailing. The proper way is to hold the hatchet in front of your chest with the head pointing up. Grip the handle so that your thumb is on the side pointing toward the head of the hatchet. To drive the nail, keep your arm straight and use a wrist action to drive in the nail. This will be awkward at first, but you will improve with practice. Screw attachment is not as difficult to learn. However, the worker usually will nail around the perimeter of the drywall, finishing the job with screws. Of course,
screw attachment holds better. When you are shorthanded, the tee brace can be a great help in hanging ceilings. The tee brace is simply a two-by-four board of ceiling height, with a two-by-four about end of the drywall and braces it against the ceiling, the tee holds one end in place while the worker hangs the drywall.



FIGURE 2-3 Drawing the guideline and nailing sets


Hanging the Board
Now you’re ready to hang the drywall. If the room you are hanging is longer than twelve feet, you won’t have any trouble taking the board into the room. Have your helper pick up one end of the board, and you pick up the other end. If you use your right hand, your helper should also use the right hand. Otherwise, you’ll be walking against each other, and this is very awkward. As you carry the board into the room, lift it up to the level of your head, as your helper does the same. Without breaking stride, step up on the benches. When you are on the benches, place the board tight to the outside wall and tight to the side wall. You should brace the board on the outside wall. Hold the board tight to the ceiling with your head as your helper does the same. Then reach out and drive a nail through the drywall into one of the joists, then into a second joist. After you have nailed the board to the joist, twist around and nail it to two more joists on the opposite side of the board. When you have two joists nailed on each side, you can stop holding the board with your head. Now you can nail the rest of the board. Each time you drive a nail, you must push up on the board to make it tight to the joist. If you fail to do this, the board will not be nailed properly.

The nails on the ends of the board should be seven inches on center, which means you should have seven nails there. the rest of the board. Set of nails is two nails driven one to two inches apart. Each joist must have three sets of nails in the area between the nails on the edges. These nails are placed at intervals of twelve inches. The fastest way to place the sets in proper positions is to nail the first set at the line you drew on the board. The second set can be placed approximately halfway between that set and the edge of the board. The third set will be placed between the center and the other side of the board. The illustration in Figure 2-3 shows the correct method of nailing sets.

After the first board is hung, you are ready to hang the other boards. To hang second board, measure from the end of the first board to the side wall. This board does not have to it tight to the wall, so you should allow 1/4 inch. If there is a small crack, the board hung on the wall will cover it. This board will be nailed the same way that the first board was nailed. You will also use the same method to cut this board as you did for the first one. When you hang this board, make sure that it butts up tight to the end of the other board.

The next row of drywall is hung so that the butt joint is on the opposite end of the room. The best way to do this is to hang the first row from right to left and the next row from left to right. Figures 2-4 through 2-7 show how to hang each board on the ceiling. All ceilings are hung using the same system.

Hanging in a Small Room
If the room you are hanging is less than twelve feet long, it will be difficult to get the board into the room. When you walk into the room with the board, the first person should hold the end of the board up to the top of the wall next to the ceiling, while the other person bends down with the other end. While the first person holds the board up to the ceiling, the other one walks around to a bench. After both are next to the benches, the second person can then raise the board up. Both can then lift the board up to the ceiling.









When hanging drywall in a closet, don’t use just little scraps. This is one of the worst mistakes a hanger can make. The closets should be done with the same care as the rest of the house. Too many small pieces of drywall can make the finished job look unsightly. For a more attractive appearance, use the largest excess pieces you can find for small areas like closets.

It’s important to check all the nails and pull out any that missed the stud. When you pull a nail out, it will leave a small piece of paper sticking out. This piece of paper should be tapped in with a hammer so that the finisher can cover it with joint compound. Any bent nails with the paper torn around them must be replaced because they won’t hold, and the board could crumble around it. Always use a screwdriver, not a hammer, to drive in or take out any screws that have missed studs. When you hang the first board, you may find that the wall is crooked. The way to alleviate this is to hang the board so it is square in relation to the center of the joist. You can put a piece in later if there is a space at the outside wall.

THE WALLS
After you have finished hanging all of the ceilings, you are ready to hang the walls. This section shows you how to hang a wall without any openings in it. The other types of walls will be discussed in the next section.

HANGING THE TOP ROW
Start hanging the walls in one of the back rooms just as you did for the ceilings. Hang the outside wall first, then the side walls, and the wall with the door opening last. This is done so that each board can fit tight to the previous one. When you hang a wall, always hang across the entire wall with the top boards before you start hanging the bottom boards.

The drywall on the ceiling needs three sets of nails in the field. The walls need only two sets. You can use guidelines drawn across the board in the same way you did on the ceiling, except these boards need two lines drawn on sixteen-inch centers.

After you have hung a few houses, you will find that you don’t need the lines for guides anymore-experience is the best teacher. Check the nails each time you finish nailing off a board. Pull out any nail that missed the stud, and replace any nail that tore or broke the paper. Make sure that all nails are dimpled (sunk into the drywall). Later, this indentation can be covered

If you are using screw attachment, use a screwdriver to place the screw deeper. Pull out any screw that missed the stud, and tap in any loose paper. Check and trim all outlet holes before nailing off the board. After the ceiling is hung, you will notice that the top plate runs the length of
the wall, just under the ceiling layer of drywall. The top plate is helpful because you can start nails on the top of the board before hanging it.

To measure the length of the board, have your helper hold the end of the tape to the side wall as high as possible. You stretch the tape out to the last stud that a twelve-foot sheet of drywall will span. Read the measurement at the exact center of that stud. Go to the stack of drywall and cut the board to fit, as you did for the ceiling board. Start a row of nails that will fit to the top of this board against the ceiling.

When you and your helper carry the board into the room, the first to enter the room should walk directly to the corner. Then both of you should pick the board up to the ceiling. After you have the board up, hold it tight to the ceiling, reach up and drive in a couple of nails that you started on the top of the board. Once you have two or three nails driven in, you can let go of the board, but you must push the board up tight to the ceiling each time you drive a nail in until the top
is completely nailed off.

Sometimes the ceiling may be bowed in places, and the top board may not fit tight to the ceiling. When this happens, make sure that the ends of the board are level. If there is a space at the top of the board, you can put a piece of drywall there.

When you need to cut a piece of drywall for a space, you should try to cut it from a piece of board that still has the factory edge. It will hold together better. When you nail off the board, the nails on each end should be eight inches on center, which means you should have eight nails there. The field is nailed with two sets of nails on sixteen-inch centers from the edge of the board. The best way to nail on the wall is to stand in front of the stud. Hold a nail against the wall in the approximate area of the stud. Glancing up and down a few times will enable you to see where to nail. To determine if the nail missed the stud, look at the head of the nail. If the head is sunk into the board more on its right side, then that means it is to the left of the stud and vice versa.

A good way to utilize time is to have your helper finish nailing off the board while you cut the next one. When you measure for the next board, remember that you can cut it a quarter inch short to make the board fit into the corner more easily. Also, a quarter inch leaves a little room for settling of the house.

HANGING THE BOTTOM ROW
After the top row is hung, you are ready to hang the bottom row. On the ceiling, of the first row. You should not do this on the wall because you must keep each board tight to the previous board. Hang from the wall that has already been hung, taking care not to break the joint on the same stud as in the first row. Butt joints should be at least three studs apart.

When you are nailing the bottom board to the wall, do not put the bottom nail any higher than three inches from the floor. The best way is to nail to the bottom plate on approximately twelve-inch centers. If you bend one of the nails, don’t worry about pulling it out because it will be covered by the baseboard. But be sure to sink each nail well.

The bottom of each wall usually will have one or two electrical outlets. You can measure and precut the hole for each outlet. This method works because you can get an accurate height measurement from the top. However, the side measurement often will be inaccurate if the wall is off the stud or if the stud is twisted. There is another way that is faster and easier, and the hole will be more on center than it would be by precutting.

Cut the board to the correct length. Then measure from the bottom of the top board (not from the floor up) to the top and bottom of the outlet, drawing a line at these points across the board. Carry the board into the room and put it in place. Using the hatchet, grasp the top of the board and hold it out from the wall just enough to see clearly behind it. Look down at the electrical outlet, then glance from the front side of the board to the back. This should enable you to see where to mark the front. Use the blade of the hatchet to mark the location for each side of
the electrical outlet. After making the marks, pull the board out from the wall and saw out the hole. The first few times you do this, you will probably miscut, but don’t be discouraged. It takes practice. For more guidance, refer to Router Tool, Figure 1-7.

When you are ready to hang the board, place the toe jack on the floor in the center of the board. Kick it under the board and then step down on it, raising the board up tight to the bottom of the hrst board so you can nail the board off. Before you finish nailing off the board, check the outlet holes and trim them if necessary. The side walls will be hung the same way, but be sure to keep each board tight to the adjacent boards. Some builders do not use baseboards. When this happens, the bottom row is set on the floor and nailed into place without picking it up to the
other board. A board % inch thick is usually ripped and used in the crack between the boards (Figures 2-8 through 2-12).

USING ADHESIVES
If you want to use glue on the wall, apply it only to the studs or to a board that you will be hanging within a few minutes. After the glue is in the open air for fifteen












FIGURE 2 - 12

the gun up the wall with the nozzle pointing forward. Hold it at an angle to the stud. Place the glue in the general area that the nail sets would be. Do not put glue in an area larger than this. The ends and sides of the walls still will have to be nailed, so there is no need to put glue in this area. After the board is nailed on the ends, go back and put one set of nails on each stud to hold the board tight to the wall until the glue sets.

WALLS WITH OPENINGS
You have seen how to hang a wall without any openings, but a wall with an opening, such as a window or a door, will be hung in a different manner. There are two ways to hang a wall with an opening. One way is called picture framing, and the other way is called headers.

PICTURE FRAMING
Picture framing is a method in which you hang the board all the way across the wall and then saw out the opening for the window or door. This is by far the you must make the joint over or under the window. The joint over or under a window is a butt joint, but it is much easier to finish than a regular butt joint. When you picture frame across a door, nail off around the door and then saw up the side of the door frame. Then step behind the board and score across the top of it, along the top of the door. Step back to the front of the board and pick it up as if it were hinged at the top. Score along the groove at the top and then break off the board. When you saw up the sides of the door, it’s much easier if you put pressure on the saw against the side of the door. This ensures that the saw will cut a straight line.

When you hang board across a window, you will not be able to get your hand behind the board to score along the top of the window. So you must score the board before you hang it. Measure from the ceiling to the top edge of the window. Score across the back of the board at this line. Do not score all the way across the board or it will break, but extend the score line the width of the window. After the board around the window is nailed, you can saw up the sides of it, pick it up, and break it the same way as you did the door.

HEADERS
The other way to hang a wall with an opening is to use headers. The corner of a door or window is a weak point in the structural framing. lf you hang drywall and hang only to the edge of the door or window, this joint will crack because there is movement at the weak point. However, if you hang the drywall past the edge of the door at least six to eight inches, the joint usually will not crack because the weak spot is tied in with the entire wall. You can hang farther over the door or window if you want to, but six to eight inches over is the recommended minimum. The electric router tool is helpful for the picture framing method. It allows you to cut around doors and windows with ease. The illustrations in Figures 2-13 through 2-18 show how to hang with headers.

KITCHEN WALLS

Kitchen walls that are under soffits are hung in a different manner than the other walls. Bathrooms and utility rooms often have soffits in them and are treated in the same manner. Most kitchens have a soffit running across the top of the wall for the cabinets













more electrical outlets along this wall than anywhere else in the house. These outlets are usually four feet down from the ceiling. To hang under the soffit, you will have to rip the sheet of drywall to tit. After you hang this first piece, the electrical outlets will be right in the way of the finisher when he or she is taping and floating (covering with joint compound) the joint. To aid the finisher, hang a full-width sheet first and then hang a ripped sheet under it. The illustrations in Figures 2-19 through 2-24 show how to hang a typical kitchen wall with a soffit. The edges of the soffit will be covered with corner bead, so be sure to hang the board to the edge of the frame. When you hang the soffit, use the end pieces left over from cutting the drywall. Remember to put a factory edge to a factory edge, and a butt joint to a butt joint.

Sometimes the two plumbing pipes sticking out of the wall are connected. If you cut a hole to go around both those pipes, there won’t be any drywall behind them. To avoid this problem, make a trap door in the drywall by sawing out holes for the two pipes as if they were not connected. After the holes are cut, use a keyhole saw to cut a straight line from the bottom edge of one hole over to the bottom edge of the other. Then go to the back of the board and score from the top edge of one hole to the top edge of the other. Then go to the front of the board, and pick up the drywall as if the top is hinged. You can then put the drywall in place over the pipes and let the trap door close. (Refer to Figure 2-25.)















HANGING STAIRWELLS AND CATHEDRAL WALLS
Two more types of walls require special hanging methods: the stairwell wall and the high wall in a room with a cathedral ceiling.

HANGING A STAIRWELL WALL
Most building codes require up to 3/4-inch fire-rated drywall in stairwells and under stairwells. Be sure to check building codes in your area. ln addition to this heavier drywall, there are three other problems you will encounter when you hang a stairwell wall.

First, the stairs go down the wall at an angle, so the drywall will have to be cut at an angle. Figure 2-26 shows where the upstairs wall and the downstairs wall join. No matter how good the framer is, these walls almost always sit in or out from each other.

If you hang the wall in the normal way, the second row of the drywall will be right on this joint. This is probably the hardest joint for a finisher to fix, but there is a simple way to alleviate the problem. When you cut the board for the first row, rip the board in half and hang the half-size sheet. If you do this, the second row does not go all the way down to the problem area. The third row of drywall will cover this area, and the edge of the board will be away from the problem area. When you hang the half sheet, remember to put the cut edge up next to the ceiling.
Figure 2-26 shows the half sheet and how it is hung.

The second problem is that the studs on the top wall will not usually match up to the studs on the bottom wall. You will have to put a stud in the wall so the end of the drywall can be nailed properly. (See Figures 2-27 and 2-28.) After you hang the third row of drywall, you will run into the third problem: angle cut. The illustration in Figure 2-29 shows how to use the T-square to find the first point for the angle cut. Hold the T-square against the bottom of the last upper row of hung drywall, keeping the lip tight against it. (Notice that the T-square has a lip on the top piece that keeps it from moving as you cut the board.) Move the T -square over until it stops against the stairs. Measure from the side edge of the hung board to this point. Mark a corresponding point, Point A, on the bottom of the board to be cut. Now measure from the bottom of the upper board to the point at which the stairs begin. Mark a corresponding point, Point B, on the board to be cut. Now measure from the bottom outside edge of the upper board
to the floor. Mark a corresponding point, Point C, on the board to be cut. Finally, draw a line connecting the points in order. Follow this line for the cut. (See Figures 2-29 through 2-31.)













To cut the board for the stairwell angle, use your utility knife and score along the line connecting B and C. Now you can lift the board up and cut this piece off. The board is now ready to hang.

HANGING CATHEDRAL WALLS
The angle cuts for the cathedral walls will be done with the same method, except that the T-square will be pointing up instead of down. The cathedral wall also will be hung with a board ripped in half, but you will start the board at the bottom of the wall and go up. You also will have to put a stud in this wall to match the end


FIGURE 2-32















HANGING ROUND WALLS
On the following page you will see an illustration of a typical round wall. Drywall that is 1/2 inch thick would not bend around such a wall without breaking. To hang a round wall, use two layers of drywall 1/4 inch thick. This thinner board will bend a little, but if it doesn’t bend enough, use one of the following methods to bend it more.

When a scrap piece of drywall is left leaning against a wall overnight, the piece will be bowed by the next morning. This is because of the moisture in the air. To bend the drywall, therefore, lay it across two sawhorses in the evening, and place a weight in the middle. By morning, the drywall will be bowed enough for you to hang it on the wall without breaking it (Figure 2-40).

A quicker but somewhat tricky method is to wet the board down. A problem that sometimes occurs with this method is that the paper is loosened from the inner plaster, causing blisters in the board.

A round wall is hung the same as any other wall, so there should not be any problems. When you hang the wall, make sure that the butt joints are away from the curvature of the wall for a better Ht. When a round wall is hung, the butt joints



of the first layer of drywall should not be on the same stud as the first. You will be able to nail the stud only on its edge, as it will stand at an angle to the board (Figure 2-41).



An archway or a tighter curve may need to be cut on the back at one-inch intervals as shown in Figures 2-42 through 2-44. Any metal corner bead needed for such a tight curve also can be cut at one-inch intervals on one side only, as shown in Figure 2-44.

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