How To Make Roof Rafters

The first step in building the roof rafters is to cut one rafter board to length with the ends angled properly and then to mark and cut the birds mouth and seat on the rafter.

How to make roof rafters.

Let s consider a basic gable wood roof framing design. You can use common rafters on any shed roof but they make the most sense when constructing a gable roof or lean to type shed roof where they can sit on or attach to top plates of a wall. Lean to rafters then connect to a ledger board against a wall of another shed or house. Laying out hip valley and jack rafters takes experience and skill but if you re building a simple gable or shed roof all you need is the common rafter the basic building block of roof framing.

Measure from the bottom end of the plumb cut line marked in step 5 and make a mark at 2 inches. Continuing on from part 3. For example if your roof is 24 feet long you can have a 4 12 roof pitch. From this measurement mark a line square to the plumb cut line to the bottom edge of the rafter.

Here we have a wood framed gable roof. When you cut the rafters you ll need to make 3 separate cuts. This video shows how to make roof rafters with a rafter square and or a speed squ. Build a fink truss to bolster a floor roof or deck.

Before you begin building rafters you need to determine that you have the right tools materials and measurements. How to build a shed roof step by step. To lay out a common rafter you need the pitch of the roof expressed in units of rise per foot of run in the gable roof example shown here a rafter with 6 in 12 pitch rises 6 in. The ridge cut also called the plumb cut at the top of the rafter the birdsmouth cut.

For every foot. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter. This marks the notch or bird s mouth cut of the rafter which rests on top of the exterior wall.

The first thing to determine is the pitch your roof will have and the span your roof needs to cover. Fink trusses were originally invented for the purpose of beefing up bridges but many contractors now use them to increase the strength of interior structures. The roof rafters provide integral structural support to the roof. Building installing roof rafters.

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.