How To Make Roof Rafters

This video shows how to make roof rafters with a rafter square and or a speed squ.

How to make roof rafters.

Build a fink truss to bolster a floor roof or deck. The ridge end of the rafter and often the eve end will need to be cut to the angle of the roof slope. Building installing roof rafters. For every foot.

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. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. How to build a shed roof step by step. Continuing on from part 3.

When you cut the rafters you ll need to make 3 separate cuts. Here we have a wood framed gable roof. Let s consider a basic gable wood roof framing design. From this measurement mark a line square to the plumb cut line to the bottom edge of the rafter.

Before you begin building rafters you need to determine that you have the right tools materials and measurements. Lean to rafters then connect to a ledger board against a wall of another shed or house. This marks the notch or bird s mouth cut of the rafter which rests on top of the exterior wall. The ridge cut also called the plumb cut at the top of the rafter the birdsmouth cut.

The roof rafters provide integral structural support to the roof. 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. The first thing to determine is the pitch your roof will have and the span your roof needs to cover. 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.

In a fink truss the internal joists are arranged in a w shape ensuring even weight distribution from one end to the other. Measure from the bottom end of the plumb cut line marked in step 5 and make a mark at 2 inches. 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. Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter.

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.