How to Build a Ridge Beam Roof

A Ridge Beam Roof is a roof with a beam that runs along the top ridge and occasionally down the slope. The purpose of this beam is to provide support for all other structural elements in the roof system. There are many types of Ridge Beam Roofs such as A Shed Roof, Pitched Roof, Gable Roof, and Hipped Roof. This blog post will talk about building a shed roof with help from our handy video tutorial below! 

How to Build a Ridge Beam Roof

If you prefer written instructions, skip to the bottom of this post for some helpful images and specifications. A shed roof is a type of roof with no vertical support on either side of the ridge, so it slopes down evenly on both sides. This type of roof can be an easy installation or replacement for many homeowners. This blog post will show you how to build a ridge beam roof.

Step by Step Guide on How to Build a Ridge Beam Roof

Step One: Layout and Cut Roof Joists

To begin, you will want to layout your roof joists. The ridge beam is the roof’s spine, and the top plate’s job is to distribute this load among all of the rafters. It does this by transferring some of its load onto a pair of opposing rafters. Thus, to create a roof with a ridge beam, you essentially split your roof into two parts.

One half of the rafters will sit under the ridge beam, and one-half will be over it. In order for this to happen, the ridge beam must extend past each end wall by a distance equal to twice the length of a rafter. Using a carpenters’ square, layout the ridge beam’s cut line on your top plate by marking lines that extend from the outside wall to six inches past each end wall.

Step Two: Cut the Ridge Beam

Use a reciprocating saw to cut along the ridge beam joist layout lines. For example, if your top plate is 48 inches wide, you can use this as a guide for cutting your ridge beam. The top edge of the centerline (extending six inches past each end wall) will be 47 1/2 inches from either outside wall.

Cut the ridge beam to size using a reciprocating saw or circular saw with a straight edge guide. You may also use an electric wood chisel by drilling pilot holes at each end of the cut line and then carefully following your pilot hole points. If you are using an electric wood chisel, be sure to wear safety glasses as flying wood chips are part of the chiseling process.

Step Three: Install Support Boards

While it is possible to create a roof with beams that span between exterior walls, many carpenters choose to use two roof beams at each end of the structure. If you have only one main beam, then you will need to install support boards under the ends of the ridge beam that span between your walls. These support boards will sit on top of your end wall plates and rise to meet your ridge beam. If you want to find out more about how to build a ridge beam roof, keep reading.

Attach them by toe-screwing through the support board and into the plate using 2 inch long screws, two per stud. Next, cut supports for a ridge beam roof installation. If you have two roof beams, there is no need to install support boards.

Step Four: Install Ridge Beam

Position your ridge beam so that it overhangs each end wall by six inches. Wedge it in place by shimming beneath each end of the beam with wood scraps. The ridge will want to tip up at one end, so you will need to counterbalance this by shimming under the opposite end of the beam.

You can also use two-by-fours for this application, but they are often hard to remove later on. If you have more than one roof rafter along an exterior wall, then you will need to create a lap joint using two pieces of three-quarter-inch plywood cut to the same dimensions as your ridge beam and fastened together using deck screws.

You Can Check It Out to Keep Flag From Blowing on Roof

Step Five: Trim and Side Flashings

Once you have installed the ridge beam, it is time to paint or weatherproof its exposed areas. Cut pieces of self-adhesive flashing to fit between the ends of your roof rafters where they meet the top edge of the ridge beam. Trim these pieces to fit and peel off their backing strips. Press them into place and secure them with roofing nails driven over the top of each piece.

Now, trim the sides of your new ridge beam for a finished look and to further prevent water entry into your structure. Next, cut two pieces of matching building material to span between the outside edges of your roof rafters. Butt them up tight against the side of your ridge beam and fasten them in place with shingle nails or deck screws driven through pilot holes.

Step Six: Add Fascia

Fascia, or “fascias,” are the long pieces of siding that sit on top of your rafters along with your roofing material. They are typically made from cedar, redwood, vinyl, or pre-primed steel. First, cut these fascia boards so they overhang the top edge of your ridge beam by six inches. Then, attach them to each rafter along the length of your roof with galvanized finishing nails.

Use a nail set and hammer to sink the nailheads slightly below the surface of your fascia boards, then fill these holes with matching exterior wood putty. Finish installing your fascia board by running a bead of caulk or exterior sealant along the top edge of your ridge beam. This will help in how to build a ridge beam roof.

Do You Need a Ridge Beam for Rafters?

A ridge beam is a horizontal structure that runs along the roof’s peak and supports the rafters. Without a ridge beam, your roof can fall if too many rafters buckle at once. The ridge beam also prevents sagging and increases the overall strength of the roof system. The ridge beam is a common feature of traditional roofs all around the world, including modernized countries.

The main purpose of a ridge beam is to support the rafters; if you do not plan on using rafters in your project, you do not need a ridge beam. However, even if you decide to use rafters, it is best to put in the ridge beam for an extra level of strength and stability under your roof design because rafters are designed to hold only their own weight – they are not meant to hold up other parts of the roof.

Frequently Asked Question

What Size Should a Ridge Beam Be?

A ridge beam is a joist that runs along the top of a wall or ceiling. It is used to support the weight from above and prevent the wall or ceiling from sagging. The size of a ridge beam depends on how much weight it needs to support, which can vary according to the building materials used in construction.

Generally, a 2×6 or 2×8 ridge beam will be sufficient for most residential homes and smaller commercial buildings.

Why Must a Ridge Board Be Wider than The Rafters?

The rafters must be wider than the ridge board to allow for a space for insulation between the two. The ridge board should also be installed over a joist and not directly on top of it.

Ridge boards are used in roofs to help prevent ice dams from forming during the winter months. They are typically installed above the roof decking but can also be placed below if needed.

Does Ridge Beam Need Support?

Ridge Beam is a type of steel beam used in buildings and construction projects. It has been used for centuries to provide structural support and stability in buildings, bridges, and other structures.

It is important to understand that the term “ridge beam” does not refer to a specific kind of beam or support system.

Does Ridge Beam Carry Load?

Ridge beam carry load is the design of a timber construction where a horizontal rafter supports the weight of an upper floor. It is used for lightweight, temporary structures such as sheds and lean-tos.


Last but not least, here are some tips for building a ridge beam roof. Consider the following when planning your project: -Use a level to make sure you have a perfectly straight line in between two walls. If possible, use stakes and string lines to create guidelines before nailing boards together with nails or screws.

Ensure that they’re high enough so that water doesn’t collect on them during rainstorms or snowmelt. -The width of the wall should equal about 1/3 of the height of the wall before it meets at an angle near where one board will be nailed onto another board across from it. In this blog, we’ve laid out a few tips on how to build a ridge beam roof.

Check it out also – How to Extend Roof Line .

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