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This section covers the construction of new walls and partitions for the extension or the existing house and the cutting of openings into existing ones. The preliminary design of load-bearing and non-load-bearing walls and partitions is covered here. Most interior partitions are constructed of 2 x 4 studs. The extension’s exterior walls, however, should be constructed of 2 X 6’s to allow for at least 5½” of insulation. Tools: CONSTRUCTING NEW WALLS and PARTITIONS LAYING OUT THE EXTENSION’S EXTERIOR WALLS: Take a long tape and a spool of chalk line to one side of the platform floor and measure inward 5 1/2” (or 3 1/2” if you are constructing 2 X 4 exterior stud walls) for the width of the sole plate. Snap a chalk line along the exterior wall at the 5 1/2” (or 3 1/2”) line (line A). Do the same for the adjacent exterior wall. Materials 2 X 4’s and /or 2 x 6’s for the studs and plates. Wall sections are constructed primarily of 2 X 4 and 2 X 6 stud stock. Most lumberyards stock lumber that's stamped “stud” at the end. Usually this lumber is of slightly poorer quality than the joist or beam material, but it's adequate for the job since most of the loads we will be supporting will be compressive. Try to purchase the studs at exactly the length you will need or a little bit longer. For the posts hidden in walls we will need thicker sections, either 4 X 4’s or two 2 X 6’s of better quality, or composite sections built up of 2 X 4’s or 2 X 6’s • 4’ X 8’ plywood sheathing for the outside walls • Window and door headers, if required • Nails: 6d, 8d, 10d, 16d LOCATING THE PARTITIONS: Locate the first partition by measuring the actual dimension of the room (let us say 11’) and add ½” or / each for the gypsum board of both exterior wall and interior partition. (If you are locating a partition in the existing house, you need only add for the new partition.) This is the real dimension between the sole plates. Draw an X on the far side of the chalk line to remind you which side gets the plate. Be careful in laying out the sole-plate locations. There may be some partitions that need to be wider than the usual 2 x 4 stud width to accommodate pipes in the wall or built-in shelves. LAYING OUT THE TILT-UP SECTIONS: It is easiest to construct short sections of the wall (about 6’ to 8’ in length) and then tilt them up into place. Longer sections of wall are practical if you have the labor to lift them in place. If you build the walls in sections, determine where the breaks will be. Organize the breaks so that they don't fall in the middle of a door or window, but between these openings. LAYING OUT THE WALL and PARTITION OPENINGS: Using a red pencil (so that these markings will stand out from the others), measure and locate both sides of the door and window rough openings and mark them. The rough opening is a bit different from the size of the window, so check the manufacturer’s literature to verify. Indicate the location of the inside trimmers, the studs that will support the header, by writing “IT” on the outside of these red marks. Then 1 1/2” beyond write “OT” to indicate the location of the outside trimmers. Add a red “C” to the X’s marking the stud locations within the opening, to indicate that they will be cut (or “crippled”). For the extension’s exterior walls, cut the sole plate and lay it around the perimeter edges of the platform, even under doors and sliding glass doors. Tack the plates down at each edge so that they will not shift off position. (Tacking is temporary nailing—you don't hammer the nails all the way down to the wood.) Next construct the corner posts. Corner posts can be arranged in a number of ways as shown below. For the extension, we suggest that you assemble the wall sections first, raise them into position, and then build up the corner posts by joining the sections and adding blocking as shown. Keep in mind that there we will eventually apply sheathing to these sections which will cover the corner post and add rigidity to the structure. (Some carpenters build the corner posts as part of one of the tilt-up sections. The topmost plate is later lapped over the lower top plate.) To lay out the studs on the exterior wall of the extension, start at the corner of a long wall and measure 48” (the width of a sheet of plywood). Add 3 to the 48” so that the sheathing will be centered on the 1½”-wide stud. Mark the OF XTEN &6 plate (point A). From that mark measure back 16” and then another 16” and place X’s on the side of the marks closest to the corner. From point A outward mark the plate every 16” and add your X’s, regardless of where the openings fall. (The plates under the doors will be cut away.) Having completed the stud markings on the first long side of the extension, cross over to the parallel exterior wall and mark the studs on that side. For the perpendicular wall follow a similar procedure. Mark 8’ from the corner of the house plus 3/4” and then mark back 16” and then an other 16”. The distance between the first and second studs in from the corner will be short (only 8 1/2”) but the sheathing will eventually cover and join the entire corner. When you get to the ends of the walls, be sure that there is a stud 8’ from the corner to nail the sheathing to. Since sheathing is so important to the stability of the structure, we want a full-sized piece of sheathing at the corner. It is likely that you will have to make adjustments in the stud spacing and will be required to cut at least one sheet of sheathing down. New partitions are laid out in a similar manner. Where walls intersect partitions, remember to provide a nailing surface for the gypsum board. LAYING OUT THE INTERSECTIONS OF PARTITIONS, and PARTITIONS and WALLS: Special provisions should be made where the partitions abut the walls. The sturdiest accommodation is made by adding two or more studs as shown in Illustration 4B. It is essential that the partitions have sturdy nailing surfaces. If you are abutting a new partition to an existing one, make sure there is a stud in the existing wall or partition at the point of juncture. If there is no stud to nail your new load-bearing construction to, you will have to remove the gypsum board and install a few studs at that point. If the partition is non-load-bearing and in a noncritical area, you may be able to nail your new stud into the sole and top plates of the abutting partition. ASSEMBLING THE TILT-UP SECTIONS: For the top plates cut pieces of 2 X 6 (or 2 X 4) to the lengths of the sole plates. Transfer all of the markings from the sole plates to the top plates by laying the loose pieces of lumber side by side with the sections that are tacked down and transferring marks with a carpenter’s square. Remove the tacks from the sole plates and move the matching pairs to a level spot. Determine the length of the studs and cut them down to size. Be sure to cut the ends at perfect right angles. Once you cut one stud you can use it as a template to measure the other full-length studs. Position the full-length studs as indicated by the X’s on the sole plate and nail top and bottom to the plates using two 16d nails. Make sure the assembly is square. Tack diagonal bracing to the frame and completely nail the studs to the plates. CONSTRUCTING TILT-UP SECTIONS WITH ROUGHINGS: For each window, position the studs that will be used as the outside trimmers and nail them to the OT marks on the plates. Measure and cut the inside trimmers to the height of the rough opening (; cut and nail them to the red IT’s on the plates. Measure the distance between the trimmers and cut the sill. On the inside trimmers, measure to the bottom of the rough opening and install the sill. Measure the header lumber and assemble the header. Position the header on top of the inside trimmers and nail to both the outside and inside trimmers. Measure and cut the crippled studs for the top and bottom of the rough opening and nail into place. Check for squareness. Tack 1 X 4 temporary diagonal bracing to the studs. Make sure that all parts of the assembly are securely nailed. Constructing and Modifying the Walls and Partitions RAISING THE TILT-UP SECTIONS: You may need a few friends to help raise the tilt-up sections. Be sure the sole plates are resting on the correct side of the chalk lines. With a few temporary nails, tack the sole plate to the platform floor, and brace it with 2 X 4’s as shown in Illustration S. Before the wall sections are secured permanently, they will have to be plumbed. This is best accomplished after all of the wall sections are completed. ASSEMBLING THE CORNERS: When all of the sections are completed and temporarily braced, the corners are plumbed and permanently nailed. For the corners of the extension (, one piece of wall section should come flush with the outside of the platform. The other, intersecting section should butt up against it. A third stud length should be Cut and positioned between the two, as shown. This stud not only stabilizes the corner but also provides a nailing surface for the interior gypsum board. == == HEADERS: There are many openings in the wall of a house— for windows, doors, pass-throughs, and so on. Since many walls and partitions are load-bearing, some provision has to be made for the transfer of loads over and around these openings. The header, which is framed over the window opening, acts as a beam to transfer the loads to the trimmer studs. The header can be made up of beam material (4 x 6’s or 4 x 8’s), but it's more economical to build up this piece out of two or three pieces of 2” material (two 2 x 8’s or two 2 x 10’s). For 3 1/2” walls place two pieces of joist material on edge. Since each piece is 1 1/2” thick, a continuous 1/2” piece of plywood is nailed in between as blocking to bring the composite width up to the width of the 3 1/2” studs and trimmer. For a 5 1/2” stud you can use three pieces of joist stock. Nail two of them together and fill the space between them and the third piece with blocking. Very often the distance between the header and the double plates is too short to justify the placement of crippled studs. In such cases an oversized header is often used that fills in the space from the top of the window to the plates. The length of the header is equal to the rough opening plus the width of the trimmers (1 1/2” x 2” pieces of trimmers). If the header is longer than 6’ you might consider tripling the trimmer so that the header rests on two trimmers on either side. == == SECURING THE TILT-UP SECTIONS: The walls can be plumbed with a plumb bob or with a carpenter’s level. The short carpenter’s level should be used in conjunction with a long straightedge so that the full height of the wall can be checked. Often there is a slight warp in the stud and the straightedge does not lie flat on the surface of the wall. To rectify this problem, attach blocks to the ends of the straightedge so that the middle section of the straightedge can stand an inch or more off the wall. Adjust the braces until the sections are plumb. When all are plumb, and the corners nailed firmly together, nail the top plate of the double plates () onto the assembled-in-place walls and partitions. Be sure to use the top of the two plates to span the breaks between sections and to connect the partitions to the walls. Once the walls are leveled and joined by the top plate, the sole plate should be nailed securely to the platform. Be sure to nail the plate into the joists beneath the subfloor. The line of the joists can be found by looking for the nail pattern on the floor. It is important to nail the sole plate to the joists and not merely to the subfloor. Make sure there are at least two nails from the plate to each joist. If you feel that the wall is moving as you nail, you know that the braces aren't secure enough. The interior partitions that are to receive gypsum board or wood paneling will be left unfinished for the time being to allow for the placement of mechanical and electrical services. Some carpenters apply gypsum board to one side of the partition to provide stability to the section, while leaving the other side open. Instructions for the finishing of the partitions can be found in Section 32. APPLYING THE SHEATHING TO THE EXTENSION WALLS: The exterior-grade plywood used for sheathing is usually specified at 1/2” and 5/8” thick. The 4’ x 8’ sheets are nailed to the studs using 6d nails. The sheathing can be applied either lengthwise or horizontally, with most carpenters finding the horizontal application the easiest. Remember that the plywood is used structurally to stabilize the construction. Al though there are other products on the market that are called sheathing, we recommend ply wood because of its intrinsic strength. DEMOLISHING and RECONSTRUCTING WALLS and PARTITIONS Walls and partitions are intrinsically alike. The former separates the exterior from the interior (and is equipped with insulation) and the latter separates two interior spaces (and, generally, does not have insulation). Some walls and partitions are load-bearing and are critical to the structure of the building, whereas some merely delineate one room from the next. If you are considering the demolition of either a wall or a partition, be absolutely certain that it's not load-bearing. If you attempt to remove a load-bearing element with out properly shoring the surrounding structure, it's likely that the building will collapse around you. In fact, if your plans include the removal of a partition that's load-bearing, you will have to see to it that a girder and posts or columns are substituted for the structural partition to be removed. Even if your plans include the cutting of relatively small openings for doors or windows into existing load-bearing walls or partitions, you will have to make sure that special provisions are made to carry the loads around the openings. (See Sections 16 and 22 for information on structural walls and partitions.) The removal of a load-bearing wall is so potentially dangerous we strongly suggest that you hire a licensed professional to determine the structural or nonstructural nature of any partition or wall you intend to remove or break into. If the architect or engineer advises you that the wall is structural, have him outline the demolition procedure, design the beam or lintel that's to replace the partition, and devise a procedure for shoring the wall while it's being replaced. Give these drawings and instructions to a competent contractor and let the experts do the demolition and reconstruction. DEMOLISHING A NON-LOAD-BEARING WALL OR PARTITION: Before demolishing or cutting into any wall or partition, shut off the water, gas, and electricity, and have the partition inspected to make sure there is no hidden asbestos. (If asbestos is found, have it removed by a licensed asbestos-abatement contractor.) Reread all of the precautions outlined in the Introduction to Demolition and Construction. Almost all walls and partitions have electrical conduit, heating ducts, or pipes running in them. Provisions must be made to cap and /or relocate all of these services. Consult Sections 33, 34, and 35 (plumbing, heating, and electrical) for instructions. Since every demolition situation is different, we can only outline the procedure generally. It is best to first remove the plaster, mesh, and lath or the gypsum board from the studs or masonry so that you can get at the wires and pipes in the wall. The gypsum board is removed by cutting the taped joint with a lath knife and prying the sheet from the studs. Plaster on wood or gypsum lath is removed by using a sledgehammer and a crow bar. (Plaster mounted on wire lath is demolished in two steps. First, the plaster is stripped off the lath. Next, the lath is pried or cut off the studs or blocks.) Cap, remove, or relocate all of the services in the wall. If you have stud walls, carefully remove the existing structure by cutting the studs at one or two points and twisting the ends out. For a non- load-bearing partition made of gypsum block (often found in old apartment buildings) or light weight cement block, you will need a sledgehammer. Remember to begin demolition at the top to prevent the wall from falling on you, and don’t store the heavy rubble in one place on the floor, unless you are sure the area can take the load. CREATING AN OPENING IN AN EXISTING STUD WALL OR PARTITION: If you are creating an opening in a load-bearing wall* (or partition) for an arch (or window), the procedure differs from the one outlined above. In this case you must be sure that the header, lintel, or beam that will span the new opening is strong enough to take on the wall and joist loads now supported by the partition to be removed. Also, you may have to reinforce the floor or wall below the opening’s end supports to receive the increased load. If the new opening’s end supports aren't directly supported by a joist or stud under the subfloor, use solid blocking to span the gap between adjacent joists or studs. *If your opening is wider than 6’ have a licensed professional outline the procedure for demolition and reconstruction. Since you will be temporarily weakening the wall supporting the floor (or roof) system above your head, you will have to provide temporary shoring to support the joists framing into that wall. In the case of a partition between two rooms, you will have to provide shoring on both sides to pick up the joist loads. Shoring is a temporary frame wall consisting of 4 X 4’s (or double 2 X 4 built about 2’ from the bearing wall or partition. First remove the plaster or gypsum board covering the wall and the adjacent ceilings in the location of the shoring. Remove and relocate the partition’s electric or plumbing services. For the shoring, nail a plate to the floor and a 4 x 4 to the underside of the joists. Measure and cut the shoring studs to fit snugly between the top and the bottom plates, then nail them to the plates. To make sure that each individual joist is supported, force hardwood shims in any gaps between the joists and the top plate. It is good practice to construct the shoring at least 3’ wider than the opening. If you are cutting into an exterior wall, the next step is to remove the siding and the sheathing to the width and the height required for the installation of the header and the jack studs. (Make sure you have a heavy plastic sheet to seal the opening from the weather.) To demolish the wall, cut the wall studs at the point where they will support the header. (Cut them at the top and bottom and twist them out.) Construct and raise the header, wedging it into place, and shore it temporarily. Install the jack studs, the sill, and other framing members and nail the assembly together. Remove all of the shoring. *Place the vertical supports at 2’ o.c. Next: Constructing a New Roof or Modifying
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