There are 2 kinds of “advanced framing”. The first is a method of framing a house with the goal of using the least amount of wood as possible. This requires a very coordinated effort between how the floor, walls, and roof are framed. The individual members may seem a bit unsteady, but when the elements of the framed house are brought together it’s really very strong. Habitat for Humanity is one proponent of using Advanced Framing.
The second use of the term advanced framing is in describing the framing in complicated structures within a house, such as spiral stairs, vaulted ceiling, and arched doorways. There’s much more math – and careful cutting – that’s required in this kind of advanced framing. This is what we’ll discuss here.
Simple framing jobs involve building square walls and level floors. Advanced framing jobs require putting together angles, curves, or compound joints; each requiring different techniques. The DIYer can still perform these types of advanced framing jobs, if they understand the basics of framing concepts.
To build a wall with an angled top, you need to remember your high school geometry. (Or find a high schooler who is passing geometry). Measure the length of the base of the wall; this will be your starting point. The length of the top plate of your wall will be different, because of the angle it will be slightly longer. You can measure the length required, or calculate it’s length by finding the difference between the height of the short side and the long side of the wall, and apply the Pythagorean theorem: A2+B2=C2. Square the base length, square the difference in side wall heights, add them together, then find the square root of the sum. When cutting the ends of the top plate of the wall, remember to cut them at the same angle as the top plate rises. You can find this angle with a speed square or a angle finder.
Each stud needs to be cut a slightly different length to accommodate the rise of the top plate. Measure and cut each stud to length, remember to measure your center points perpendicular to the side wall. For 16″ centers, your studs will be spaced more than 16″ along the run of the top plate, to accommodate the rise. An easy way to correctly space your studs is cut 2 spacers, 14 1/2″ long and use these to space your studs. With all your studs cut to length, nail them into place and raise your wall just as you would a standard square wall.
Framing curves requires that you make a lot of small blocks and piece them together to make the curve that you want. In order to make a wall that bends, you need to make several short plates, cutting the ends of each piece at an angle that measures half of the angle required at each joint. For example if your wall needs to bend 60 degrees over a 10’ length, cut 5 pieces 2 feet long each, with the ends cut at a 6 degree angle (60 degrees over 5 pieces equals 12 degrees each joint, each end cut to 6 degrees when joined together will create a 12 degree angle.
If your wall requires a curved top plate to conform to a barrel vault ceiling, then you need to make a series of angled walls (as described above) and put them into place in a series of walls. The slight open spaces left at the top of each wall will be covered by the sheathing or drywall, so your top plate doesn’t have to be perfect, you just need to fasten it securely.
In order to frame compound angles, such as chalet roofs or turrets, you need to make compound cuts at one end of the studs. The techniques required to build walls with compound angles are essentially the same as those needed to build angled walls. The cuts are angled in two directions, so with a little planning, you can figure out the required angles needed to build your walls. Using connecting plates to fasten the studs to the top plates allows you to be off slightly with your cuts, but give you a wall that is structurally sound.
Remembering these tips will allow you to complete almost any advanced framing job that you may come across. While you always want to make your framing joints as tight as possible, the frame will be covered with drywall or sheathing, so it does not have to be visually perfect underneath.