How to frame a window, build window headers and door headers (2023)

lar Skills carpentry Marco

Updated: January 17, 2018

These wooden “bridges” allow you to create many large openings without weakening the walls.

Introduction to the construction of walls.

Whether remodeling, adding, or building “from scratch,” we do everything we can to build strong, stable, and durable walls. We then cut opening after opening to accommodate the large windows, front doors, and patio doors that we love. Strange, yes. But if we create these openings in the right way, we should never fear that our walls or houses will collapse. And that "right way" means using the structural support system that has been developed over the years to keep our homes strong and happy. See why drill large window openings and what you need to know the next time you add or renovate your home.

Headers – think of them as bridges

If you were to put on those old Marvel Comics X-ray glasses (you know, the ones that can see through anything) and look around your doors and windows, you'd see something amazing. Above each window and door, you'll find a sturdy wooden bridge, and at each end you'll find supporting pillars. These bridges are not glamorous like the Golden Gate or the Brooklyn Bridge, but they are very important. It is the structural elements that allow us to install windows and doors without weakening the walls.

In the real world of architects, carpenters, and loggers, these bridges are called headers (Fig. A). The vertical studs that support each end (usually made up of 2x4s or 2x6s) are called studs and trimmers (or stud jacks). In most wood frame homes, the headboards are made from trim-installed dimensional lumber. Kingpins driven into the end of each headboard and sideboards that fit just below the headboard combine to create a strong vertical support column. Together, the headers, head studs, and trim act as a system that transfers weight from above, below, and around window and door openings to the floor and foundation below. The greater the distance a platform covers and the heavier the load it supports, the more substantial it must be. Undersized decks will tilt, compressing windows and doors and making it difficult to operate. They will also crack the drywall and distort the finish. There is no simple rule to determine exactly how long a header should be. But you have to get it right when you proceed with this how to frame a window design.

Hey Einstein, how big should this header be?

Figure B: Example header size calculation

The header size is required to support the roof, roof, and a 28-foot center support floor. great building; 30 pound snow load.

(Based on the 2000 International Building Code)

Calculating the size of the header is tricky as you learn to frame a window. You must consider: (1) the length of the window or door opening; (2) the combined weight of the floors, walls, and ceilings above; (3) the width of the building; (4) the snow load in the area; (5) whether it is a load-bearing wall (where the beams, trusses, and rafters rest) or a non-load-bearing wall (to which the beams, trusses, and rafters run parallel); (6) whether it is an external or internal wall; and (7) what type of wood you are working with. The 2000 International Building Code book contains two full pages of mind-blowing charts for calculating proper header sizes in different situations. Fig. B shows the maximum spans allowed for headers of different sizes in a single situation. Unsurprisingly, the deeper the header, the more distance it can cover. But trust me, you don't want to get into all the technical details. There is no simple formula. My advice is this:

1. Ask an engineer or architect to calculate the required header size for window and door openings.
2. Ask your local building code official to help you calculate the size of the header. It's usually not in your job description, but the good guys will help you.
3. When in doubt, build a 2×12 double header sandwich as we explain below. In all but the strangest of situations, they will easily support the weight of 4 feet. wide window and door openings and, in most situations, meet code for openings up to 6 feet wide, a common patio door width.

Calculating the size of the header is not an easy task while learning how to frame a window. These are the allowable ranges for header sizes in just one of hundreds of situations. If your renovation or construction plans were not prepared by an architect or structural engineer, work with your building code official to determine
the correct header size.

The header size is required to support the roof, roof, and a 28-foot center support floor. broad
building; 30 pound snow load.

The clever way I used to create headers

My first job as a carpenter's helper was building the heads of the houses we were building. I would cut and nail "header sandwiches" consisting of two 2x12 1/2 in. offset between (Fig. A). This size worked well because:

1. 3-1/2 in. finish thick (1-1/2 in. plus 1-1/2 in. plus 1/2 in.) 2 in.; see figure EL).
2. When we installed the heads even with the top of the standard 92-5/8 in. in height, we set the appropriate height for windows and doors (Fig. A).
3. Since the architects and engineers who designed the homes figured the 2x12 studs were deep and strong enough to span the largest opening (6 feet), they were certainly strong enough to span the largest number of small openings. By overbuilding, we carpenters could concentrate on building houses, without looking at complicated charts to determine window and door header sizes. This is everything a woodworker (and DIYer) could ask for in a deck: just the right thickness, height, and strength.

Trimmers, cripples and sills complete the preliminary opening

Three more components are used to end started job headers:

Clippers (Fig. A) fit and support each end of the header and are nailed to the main dowels next to them. Longer and more weight bearing heads require two or more sideboards to be supported at each end, and some openings require more than one kingpin. Again, check with your local architect, engineer, or code official to determine when you need to install additional trimmers or kingpins while learning how to frame a window.

Sills (Fig. A) establish the bottom of the rough window openings (the clear opening required to install windows and doors). With large window openings, it is a good idea to use double sills (Fig. A) for strength and stability when framing a window.

Crippled pins (Fig. A) fill the space between the sills and the 2x4 cleat plate below; they only support the weight of the window itself. Padding is sometimes installed over a window or door (Fig. C) to fill the space between the top of a header and the top of a wall. These carry weight. As a bonus, all that extra wood provides an ideal anchor for the nails used to install wood trim and framing, especially the wide materials.

Additional Information

• Figure: A

Tools needed for this project

Have the tools you need for this how-to-framing-draw-window DIY project before you start will save you time and frustration.

• Air compressor
• air hose
• circular saw
• extension cord
• extension ladder
• framing square
• Hammer
• Level
• miter saw
• reciprocating saw
• safety glasses
• easels
• Measuring tape
• wrecking bar

Materials needed for this project.

Avoid last-minute shopping trips by having all your supplies ready ahead of time for this window framing project. Here is a list.

• varies a lot

Original message: January 16, 2018