ENLARGING THE GROUND FLOOR--Opening the Common Wall

The opening between an addition and the house is easy to provide in most cases. Because many additions become separate rooms, you may be able to convert an existing door or window into an entrance. Or after the addition is weathertight, you can cut a new opening in the house wall and frame it for a door. A wider framed opening, one large enough to be considered an archway, serves well if a room is being extended for a distinct purpose—to add a dining area, For example.

- Removing the Whole Wall: When the addition is meant to expand a room, however, seamless walls and ceilings are often the goal. In the bearing wall of a one-story house, there is no easy way to support the house rafters except with a header below the ceiling. But in a nonbearing wall, or a bearing wall on the ground floor of a two- story home, a low-hanging header can be avoided.

To provide a seamless opening in a nonbearing wall, cut away part of the adjacent ceiling to reveal the joists, which generally run parallel to a nonbearing wall. Reinforce the joist above the wall by nailing to it a piece of i-inch plywood and a board the same size as the joist. Then remove the wall below.

- Opening Up a Bearing Wall: To provide a seamless opening in a bearing wall of a two-story house, proceed as shown here. The job requires reinforcing the header joist above the house wall with laminated veneer lumber, or LYL; consult the dealer for advice on how many LYL boards of what size to use.

If you are using a shed roof, as is usual for a room extension, fasten the ceiling joists of the addition to the rein forced header joist.

CAUTION---Check the siding and interior walls for asbestos and lead paint as shown; if either is present, take the precautions indicated there.

MATERIALS:

• Plywood (0.5”)
• Nails (3.5” and 4.5”)
• Machine bolts (0.5”) with washers and nuts
• Joist hangers
• 2 x 4s Laminated veneer lumber

TOOLS:

• Keyhole saw
• Chalk line
• Pry bar
• Handsaw or reciprocating saw
• Maul (0.5-pound)
• Stepladder
• Hammer
• Electric drill
• Auger bit (9/16”)
• Open-ended wrench

SAFETY TIPS---A dust mask is helpful when you are cutting into wallboard, and goggles are needed when you are sawing overhead. A hard hat offers protection as you reinforce the header.

A seamless opening.

64---

For uninterrupted walls and ceilings on the ground floor of the addition, the weight of the second floor—formerly carried by a bearing wall—must be sup ported by a doubled or tripled header joist resting on posts made from 2-by-4s. The reinforcement consists of laminated veneer lumber (LVL) bolted to the addition side of the existing header joist. The ends of house ceiling joists, which had rested on the top plate of the old bearing wall, are hung from the header with steel joist hangers, as are the ceiling joists of the addition.

A HEADER CONCEALED IN THE CEILING

1. Removing the wallboard.

65a---

• Support the second floor with temporary shoring.

• Remove the studs and sole plate of the existing wall from one side of the addition to the other.

• At each side of the addition where it joins the house, cut away existing wallboard between two studs as shown at left.

• Snap a chalk line across the ceiling, in line with the studs that you have exposed; saw along the line to free a section of the ceiling and remove it.

2. Prying out the last studs.

65b---

If a corner stud from the old wall protrudes into the opening you are making, proceed as follows (for clarity, the temporary shoring shown in Step 1 has been omitted here):

• Pry the corner stud away from the side-wall studs behind it, starting at the bottom and working up.

• With a handsaw, cut off the piece of sole plate on which the stud had rested and pry it from the floor.

3. Removing the top plates.

66a---

• Cut the top plates of the old wall flush with the side-wall studs as shown above; be careful not to saw into the header joist.

• Wedge a pry bar between the upper top plate and the bottom of each joist; pry the plates away and knock them free with a maul.

• Drive 4.5-inch nails through the end studs of the addition wall into house studs where the addition meets the house. Use two nails at the top of the studs, two at the bottom; in between, drive single nails every 6 inches in a staggered pattern.

4. Supporting the header joist.

66b---

• Cut two studs one saw blade-width longer than the studs in the wall of the addition.

• Hammer one of the boards tightly against the end studs in each side wall of the addition.

• Secure these support studs to the end studs with 34-inch nails following the nailing pattern described in Step 3. Then toenail the new studs to the top and sole plates.

TRICKS of the TRADE --- Toenailing Made Easy

67a---

Holding a nail at an angle when toenailing a stud to a plate, For example, can be frustrating; the nail’s point tends to slip when you strike the head. To simplify the task, place the head of the nail against the stud at the desired entry point and angle, then tap the point, blunting it slightly and denting the wood. Then turn the nail around and drive it through the stud using the dent as a shelf to keep the blunted point from slipping.

5. Assembling the header.

67b---

• With at least one helper, set the first LVL board beside the header joist, resting it on the top plates on each side. Tack it to the joist with a few nails.

• Toenail the LVL board to the top plates or secure it with metal rafter ties.

• Attach each additional board the same way, sandwiching rafter ties between boards as needed.

• Depending on the thickness of the header assembly, fasten the components together either with nails or 0.5-inch bolts. For bolts, drill 9/16-inch holes with an auger bit, and place a large washer between the wood and both the bolthead and nut.

• Connect both house- and addition ceiling joists to the header with joist hangers.

• Remove the shoring.