stick built rafter spacing for metal roof

But let us get into some specifics, shall we?Īt light loads, 2nd-grade SYP lumber 2×4 rafters span 9 feet at 12 o.c spacing. Generally, 2×6 rafters span longer than 2×4 at any dimension and for any lumber type. So, 20 pounds per square foot (PSF) tallies light loads. The span length also drops with increased load readings. Regardless of the lumber type and grade, the span length decreases with increased o.c. Those factors must meet wind deflection and live/dead load limits. Typically, the maximum span length for 2×4 or 2×6 rafters depends on the lumber type and on-center (o.c.) spacing. It is sturdy enough to help deflect winds and stay intact.ĭo well to consult the wind load chart to know the wind speeds for your area. As per wind, 2×4 works for areas with light winds (winds with low velocity).īut the 2×6 is a good fit in hurricane-prone areas or locations that get strong winds. So, 2×6 is the real deal if you want to go for spans longer than 22 feet. Generally, 2nd-grade SPF (spruce, fir, pine) gives a longer span than SYP (Southern yellow pine). But again, the 2×6 is the best choice for heavy snow loads.Īlso, the lumber type for the rafter determines the span you can get. But generally, a 2×4 is a safe choice in an area that does not get much snow.īoth 2×4 and 2×6 rafters can get up to 22 feet spans for shed roofs. Light snow loads on roofs with 2×4 rafters may still wreak havoc if the pitch is closer to 3:12. But the slope of the roof is still critical here. More gravity equals more load.įor snow loads, 2×4 fits for light snow loads and the 2×6 rafter for heavy snow loads. It is basically down to gravity.įlat roofs tend to have more gravity weighing down on them. That is, roof structures with slopes that are less than 3:12. First, 2×4 should go nowhere near flat roof structures. Should I Use a 2×4 or 2×6 Rafter for a Shed Roof?įor shed roofs, lumber, roof slope, span, snow load, and wind determine the verdict between 2×4 or 2×6.

The 2×4’s build does not fit flat roofs, no matter the spacing between the rafters. For slopes that are less than 3:12, the 2×6 rafter can serve. The 2×4 rafter goes for 3:12 slopes and greater. The slope of the roof also determines the rafter size you should use. Talking about caving in, the slope of the roof comes into play. You would not want your roof to cave in after it stands for some time. The 2×6 offers better structural support compared to the 2×4 rafter. It is wise to keep 2×4 rafters for small setups and 2×6 rafters for large ones. It is a no-brainer large structures have large roof sizes, and small ones have small roofs. So, the rafter size should match the roof size.

The primary role of the rafter is to support the roof. On the other hand, it fits in conditions that translate to light snow loads.Īnother thing to consider is the size of the structures on which you intend to use the rafters. The 2×6 serves to support roofs in areas that get heavy snow loads.īut the 2×4 would not hold for long under heavy pressure. Wind deflection and snow load have parts to play in choosing between 2×4 or 2×6. Sometimes, you can use the 2×4 to achieve longer spans if the spacing between the rafters is less.

The 2×4 rafter goes for shorter spans, and the 2×6 goes for longer roof spans. First, you should know the roof span you would like to achieve. The size of roof rafters you use depends on a couple of factors.

Stick built rafter spacing for metal roof