Which is Better: Roof Trusses or Stick Framing? Part 1
There will always be the argument of which is better: Roof trusses or stick framing? And there are some valid arguments for each. In the end, it all boils down to cost-effectiveness right? In this article we will explore both sides of the story.
You have the “old school” framers who either prefer or are afraid of change, choose to cut in roofs with rafters and there are the “new school” framers who prefer trusses as they can “create” the roof in a matter of hours and save money in the amount of labor it takes. I can understand some of the arguments against trusses and I can understand some the arguments against rafter frame as well. Here are some of the things that I feel are pros and cons of both that I have learned from my experience in the construction industry as a truss designer.
Roof Trusses – Pros; Stick Framing – Cons
- Cost effectiveness. How you might ask? Well for starters, it eliminates hours, possibly days of time cutting in roofs with rafters. If a house is fully trussed, a framer has almost nothing to over frame. That means a few hours setting them and then right to bracing and sheathing. Whereas with rafters, you typically have multiple ridge and valley beams that has to be set, birds mouths or plate connectors have to be cut in or attached. If that wasn’t enough, if the ceiling is flat, you then have to go back and add in the ceiling joists. This adds up to big amounts of dollars saved, especially on “track build” homes.
- Ability to build trusses that have multiple pitches, both on the roof and in the ceiling. For complicated houses that have dual pitched roofs or pitch breaks, the trusses designer has those built into the trusses, so all that has to be done in the field is to just set the trusses according to layout and go. Rafters will require a little bit of math and when there’s a pitch break, it will require yet another roof beam to carry the trusses on either side. Then there are the inverted hips, vaults, coffers and trays. These can all be taken care of in the trusses so that all that needs to be done is some ladder blocking for drywall and you’re ready to go. Rafters require multiple cuts, string lines, measurements, more lumber and thorough attention to detail, requiring much more labor costs.
- Clear spanning large distances. With trusses, you have the ability to span a much greater distance without bearing than rafters. As a matter of fact it’s not even close. In my personal experience, I have made a truss clear span 61’ out to out. All it needed what 2×6 top and bottom chords and that was just for rigidity for delivery. What kind of lumber, besides EWP can you find that will make that span? It doesn’t exist. With rafters you would have to have multiple roof beams to make a span like that work and multiple bearing points.
Rafter framing – Pros; Roof Truss – Cons
- Parallel roof and ceiling pitches. This is really the only area where I personally feel that rafters are better than trusses. Typically this application only applies to semi to high-end custom homes. With these homes, architects try to maximize as much space as they can and that includes ceiling height. With trusses, if the span is large enough, without internal bearing, it makes it tough to design a truss with a ceiling pitch 2 or 3 less than the roof without a decent sized heel height. (i.e. – 10/12 roof over a 7/12 ceiling.) For example, a parallel chord truss that spans 25’ may need a 16” or larger heel, plus 2×6 top and bottom chords just to counter the horizontal deflection. With rafters, it doesn’t matter is the roofs a 4/12 or a 12/12, as long as the engineering on the material allows the span of the rafter, your good to go.
As I have said, these are just my opinions on why I feel trusses are better than rafters. Obviously a case can be made for both. But in the long run, trusses will save the customer huge amounts of time and because as we all know, time is money, trusses will in turn save a lot of money. Hopefully this helps those of you out there who still choose to cut in your roofs by hand, understand a little bit better the advantages that trusses can offer your operation.
Now keep in mind, I did not even touch on the quality aspect. I think that is better saved for another post in itself.
Stay tuned for part 2.
What ways do you see benefits of each? Why do you feel one is better than the other?
Zach Failing – Design Professional
Gould Design, Inc.