Introduction to Roof Framing

From the very beginning of my framing career I was fascinated by roof framing. It was obvious to me, even at such an early age, that this was not easy thing. It was clear to me right off the bat that it involved extreme climbing, heavy lumber, harsh temperatures, and unbelievable schedules (not to mention the low wages and the high competition), but for some strange reason, framing roof systems is something I wanted to master. After all, most of my family was involved in framing in some way or another. I had a bale of cousins that did it, their cousins did it, theirs cousins cousins did it, and not to mention I grew up working for my uncle along with his brother, my brother, and my closest cousins.

Safety

It couldn’t be any fun looking at a half finished roof from a wheelchair after you fell and broke your back, or burying a friend because a beam crashed down on him. Fortunately the are steps you can take to greatly reduce the chance of an accident. First and foremost, you should be working with a competent team. The men you work often have as much “control” over your safety as you do. Avoid clumsy, non-focused, or intoxicated co-workers.

Falls are the number one cause of both injury and death worldwide. The only thing you have to walk around on is the ceiling joists and walk boards. This comes natural for for most framers. The rules are simple, never step on anything that is not braced, always watch where you’re stepping, forward momentum will help to keep you balanced, and always us two joists. Most people just can’t do it fluently. It’s simply too scary. If you and your team are not completely comfortable walking around on ceiling joists, then spread out some roof decking where necessary.

Blueprints

Some roof systems are simple; some are not. The blueprints tell all. The front, right, left, and rear elevations will let you know about the cornice levels and the roof pitches. Factor in outside wall coverings and things get juicy real quick. If you are not familiar with multiple roof pitches, different cornice levels, and different wall coverings, then you better hire a professional. It is just too complicated for a beginner to get things like this right. Stick with what you know you can do. Cutting in roof systems takes a great deal of experience and the only shortcuts are my calculators. For example, if your blueprints call for a hip roof with a main roof pitch of 6/12 and a complimentary roof pitch of 12/12, then my hip roof calculator will return, the length of the common rafter, the approximate length of the hip, the length of the complimentary rafter, and the difference at the HAP.

Tools

Use an air powered nail gun and the right sized nails; its that simple. Screws are a waste of time and money. The wrong sized nail is dangerous and so is the nail that is not driven or shot properly. I prefer a Paslode framing nailer with 3 1/4″ x .131″ grooved shank nails. These fasteners hold extremely well and the nail gun is lightweight, durable, has a hook, and shoots hard. Take care of your nail gun and treat it with respect. Its hurts to have three fingers nailed together, trust me I know. One safety factor I learned over the years is to remove the spring that keeps the safety stiff. You are much better off not having to place a great force on the safety just to get the gun to shoot. A trigger that will fire both contact trip and sequential trip is best. I like to shoot the first nail after after depressing the safety and then any subsequent nails I rapid fire.

Use a high quality 7 1/4″ circular saw with a carbide tooth framing blade. Just like the nail gun, this is a tool that should not be taken lightly. Always follow these simple rules:

  • Never operate a saw without a guard or with the guard scotched back.
  • Wear eye protection.
  • Don’t saw wood with embedded nails or any other foreign material.
  • Be careful in wet conditions. Electric shocks can be painful or even deadly.
  • These saws cut in straight lines only. Trying to make a course adjustment without backing up will only result in “binding”. This could cause a dangerous kickback or overheat the blade.
  • Remember to keep the mark you are sawing between your eye and the saw blade. This determines which side of the blade to watch. In other words, if you are sawing a board you measured from the right to the left, then you should be watching the blade on the right side of it. Keep your eyes on the side of the saw blade that’s the same for the side of the board you want to keep.

Trusses or Rafters

There are two distinct methods for roof framing. One involves prefabricated roof trusses that transfer their loads onto the outside walls only. The other consists of stick framing. This where individual framing members are installed one at a time and they distribute the weight of the roof and ceiling load.

Trusses have the advantage of speed on simple jobs. They also span open spaces much better than stick framing. The cost may vary from region to region, but for the most part they are more expensive. If it were up to me, I would stick frame everything I could except for the long spans.

Roof Framing with Trusses

Trusses can make short work for the framing of a roof on a house, but they can also be dangerous to install. Although thy are not typically all that heavy, they are imposing because of their shear size. Add a little wind to mix and you better know what you are doing. A boom truck may be necessary, but it is also a great expense. We use our SkyTrak whenever possible by improvising an extension. This is an extreme measure and we do it only because we are so familiar with our equipment, and our task at hand.

However you decide to lift the trusses into position, you have to start somewhere. It does not really matter where you begin, it does not have to be on the gable end it can be anywhere.

Stick Framing

  • You will need at least some experience.
  • All cuts must fit tight.
  • Rafters must not over span.
  • Ridges, hips, and valleys should cover the complete plumb cut of the rafter.
  • Everything has to be fastened with at least 3″ – .120″ nails. I like 3 1/4″ – .131 grooved shank round head Paslode nails.
  • Don’t get killed framing your own roof system. Hanging massive ridges or other dangerous framing membrs should only be attempted by professionals.