Spanning the distance above window and door openings, headers transfer the weight of the roof down through the trimmers, making it possible to have openings in a wall without compromising its strength. There are three things you need to know about headers: length, cross-sectional dimensions, and construction details.
Header Lengths
Window and door manufacturers typically provide recom- mended rough opening sizes for the prehung units they sell. To determine the length of a window header, you can simply add 3 in. to the rough opening size; this is the com- bined thickness of the trimmers that support the ends of the header. 4-J King stud Trimmer Double top plate Top plate Top cripple Solid 4x6 header 2x4 top cripple Flat 2x4 header
A SOLID HEADER IN A LOAD- BEARING 2×4 WALL
N The length of a door header is usually 5 in. greater than the
width of the door. Therefore, a 3/0 door (36 in. wide) needs a 41-in. header. The extra 5 in. includes 3 in. for the trimmer thickness, 11⁄2 in. for two 3⁄4-in.-thick door jambs, and 1⁄2 in. of clearance space for setting the door plumb.
N A set of sliding doors typically requires a shorter header
than a regular door—just 3 in. longer than the combined width of the pair of doors. For example, a set of 5/0 (60-in.) sliding doors requires a 63-in.-long header, which provides 11⁄2 in. on each side for the trimmers. After the trimmers are wrapped with drywall, you’re left with a 59-in.-wide opening, which allows the sliding doors to overlap 1 in. A SOLID HEADER IN A NON-
LOAD-BEARING 2×4 WALL 1/2-in. plywood or foam board 51/2in. 51/2in. 31/2in. Space for insulation 4x6 2x2
4-K
DOUBLE 2× HEADER FOR 2×4 WALL BOXED HEADER FOR 2×6 WALL BUILT-UP HEADER FOR 2×6 WALL 4-J King stud Trimmer Double top plate Top plate Top cripple Solid 4x6 header 2x4 top cripple Flat 2x4 headerGOING UP 85
TIP
“Scrap” pieces are valuable. It’s smart to collect and organize the offcuts that accumulate as you cut plates, sills, and other wall parts. (This is a great job for one or two volunteers who haven’t worked on a construction crew before.) Shorter pieces of 2× lum- ber can be used to make essential small parts, such as top cripples and blocking.N On the other hand, bifold doors require
a header 41⁄4 in. longer than the actual door size. So 5/0 (60 in.) bifold doors require a 641⁄4 in. header. The 41⁄4 in. margin leaves room for two trimmers (3 in.), a layer of drywall (1 in.), and 1⁄4 in. so that the doors will close properly.
N The standard header length for vinyl-
framed windows is 3 in. longer than the rough opening (39 in. for a 36 in. win- dow). For wood-frame windows, head- ers are cut 5 in. longer than the rough opening, just like door headers are. Make sure that the window sizes meet code requirements for daylight, ventila- tion, and egress.
Header Cross Section and Construction
N The header in a nonbearing wall can
be a single 2×. In a load-bearing wall, the length a header spans determines its cross-sectional measurement. For a 3/0 exterior door or a 4/0 window in a 2×4 wall, code requires at least a 4×4 header. A 5/0 or 6/0 window requires a 4×6 header. An 8/0 window needs at least a 4×8 header. In 2×6 walls, simply increase the thickness of the header to 51⁄2 in.
N Headers can be constructed in many
ways. They must be as wide as the wall in which they are installed. In cold re- gions, headers are built with gaps so that foam or fiberglass insulation can be added. Talk to builders in your area to find out what’s done locally, and check with the building inspector to make sure the headers you plan to use will meet code.
You can place the top plate alongside the bottom plate or toenail the top plate on edge to the bot- tom plate. These plating strategies maintain the alignment of the top and bottom plates so that you can accurately mark both plates at once.
Interior walls without bolts can be secured to a slab in various ways. You can drill through the plate and into the concrete with a cement bit. Once the hole is cleaned out, you can secure a bolt in the cement using epoxy or by using a bolt that expands as it is tightened.
Another common way to fasten a plate to a slab is by using a powder-actuated tool that shoots a hardened pin through the wood into the concrete. These tools pack serious power, so take care. Ask for training from your site super- visor before using them. Be sure to wear lenses to protect the eyes and plugs for the ears.
STEP 3 COUNT AND CUT THE HEADERS, ROUGH SILLS, CRIPPLES, AND TRIMMERS
I helped build my first house in 1948. It was a mail-order house brought to our small town by the Chicago and Northwestern Railroad, then to the site by horse and wagon. Every piece of the house frame was precut and tied in bundles. My job was to untie the bundles and bring the pieces to the carpenters who nailed them together.
Today, the same house pieces are needed, but most of them are cut to length on site. Headers are needed over door and window openings to transfer roof loads down to the subfloor and foundation. Rough sills support windows. Cripples or jack studs either support a rough sill or transfer weight from a top plate to a header. Trimmers extend on both sides of door and window openings to support headers (see the illustration on p. 87).
Before you can begin cutting or marking framing members, you need some basic infor- mation, including the standard stud length, the height at which headers will be set, the size and location of door and window openings, and
86 GOING UP
the way in which headers will be constructed. A good way to carry around this information is with a story pole, as explained in the sidebar above. Recording wall-building information on a story pole reduces the chance of error and speeds the entire framing process.