When planning a sloped roof, whether it’s a standard asphalt shingle roof or a custom metal roofing system, one of the key decisions you’ll have to make is choosing between rafters or trusses for your roof framing. In today’s post, local roofing company Arrowhead Roofing explains the differences between these two.
Rafters. Rafters are what can be considered “traditional” roof framing. Rafters are built on the top of the house structure using long planks that slope down from a central ridge beam. The rafters extend beyond the house’s footprint and create the overhang onto which soffits and fascia are installed. Horizontal planks form the attic floor and support both ends of the rafter tails, creating the basic triangle shape that forms the roof.
Framing built with rafters requires a minimum slope to be structurally sound, which is why this type of attic is suitable for conversion to a bedroom or a vaulted ceiling. The additional space also makes storm damage roof repair easier for roofing contractors.
Trusses. Functionally, trusses are the same as rafters, except that they’re more like webbed structures than ribbed ones. The key difference between rafters and trusses is that the latter are prefabricated instead of being built by hand. This helps simplify the installation process, as all the roofer will need to do is hoist it onto the house and attach it. Homes built in recent years are more likely to feature trusses than rafters.
Trusses are designed using software and can be made of materials other than wood. This allows for greater structural support — ideal for tile or slate roofing — and makes low-slope yet stable structures possible. It’s worth noting that, while installation time is shorter, the lead time for trusses will be longer, as they have to be fabricated and delivered. Lastly, trusses offer little flexibility for design changes, which means last-minute roof changes will have to be done at a significant cost to you.