For 2×4 rafter, you should use 2×6 size ridge beam. Ridge beam sizeįor rafters of size 2×4, 2×6, 2×8, and 2×10 you need to use different ridge beam sizes. Ridge beam is used when roof slope is less than 3 in 12 Ridge boards are used when roofs slopes between 3 in 12 upto 12 in 12. It is jointed at the ends with a post or support There’s no support or post at the ends.
It doesn’t take any loading or is not designed for any loadings. 2 It takes the load on the roof and on the rafters. It is a non-structural member that serves as a prop or support for opposing rafters to rest against and connect to. Ridge Beam Ridge Boards 1 It is a structural member that connects with the rafters at the ridge of the roof. Further the ridge boards must have a nominal thickness of at least 1 inch while the depth must be more than the cut end of the rafter. As per the code, you can use ridge board only if the slope is from 3 in 12 to 12 in 12. Unlike ridge beam, ridge board is a non-structural member that just acts a guide for opposing rafters to rest against and connect to. So, for the connection between rafter and attic floor bolting is considered instead of nailing.Īlso Read: What is a flitch Beam? – Purpose – Benefits – Thickness (Know ALL) What’s the difference between Ridge boards Vs. When a roof has a low-slope, it can result in high outward thrust force at low end of rafter.In case the attic floor joists are perpendicular to rafters, structural ridge beam is necessary to provide resistance against outward thrust force.A collar tie with height more than one-third of the ridge height will always need a high-end support. Also if rafter ties or collar ties may not provide enough support to roofs that has longer span.The top plate along exterior support walls won’t offer enough resistance so, high-end support on rafters is considered. That’s because such a roof doesn’t have enough resistance against outward thrust force along low end of rafters. If you have a no joists for attic floor (ceiling) as in the case of cathedral ceiling, such a roof must have a ridge beam.Further the size of the ridge beam depends on the span of the beam between the posts along with the loading conditions.īut alongside above reasons, there’re other specific reasons that require additional high-end supports for high rafters:
IRC Section R802.3 states the above requirement. You also need to have a ridge beam while installing structural insulated panels. There’re a requirements of a ridge beam as per the International Residential Code (IRC) and International Building Code (IBC) for roofs with slopes less than 3 on 12. It supports the rafters and side-walls under gravity loads as well as live load and dead load of roof structure.Īlso Read: Bond beam in masonry walls – Design – Size – Foundation – Pros & Cons Is a ridge beam needed? To prevent the ridge board or beam from separation due to uplift pressure from wind, collar ties or ridge straps are preferred.
Sometimes masonry structure within the gable wall is also feasible if other structures are there along the span. You can either use a wood or steel post at the end for the load to be transferred to the foundation. SupportsĪs the ridge beam must be supported, it must be clear to know what type of support is feasible. Although conventional hip-roof construction or a gable roof doesn’t need a ridge beam, but there’re some pros of using a ridge beam instead of a ridge board. It’s pretty easy to assemble your roof trusses if you use the ridge beam using LVL (laminated veneer lumber). It’s more stable than a conventional roof ridge board (that doesn’t sits atop the end posts) that doesn’t take any loading. Do I need rafter ties with a ridge beam?Ī ridge beam or more specifically a structural ridge beam is a load-bearing element that acts as an independent support for rafters at the apex (high end) of the roof.What’s the difference between Ridge boards Vs.