How to Build Roof Trusses for a Shed
As a side project, I decided to build a shed for my wife. Since my experience is mainly with stone and tile, I turned to a buddy who is an Austin roofer for some assistance when designing roof trusses. The following are some details of my research about shed and roof building, as well as some general guidelines of building a shed yourself.
All About Roof Trusses
Roof trusses are triangular structures that provide the support and stability to the roof and distributes the weight of the roof away from the exterior walls of the building.
Trusses are usually made from wood in residential design and from steel for commercial building design. They take the shape of a triangle because of that shape’s natural ability to disperse pressure through its entire structure making it extremely stable and rigid.
There are a number of different designs for roof trusses and the best design for any building will depend on.
- the stresses the building roof is likely to experience
- the aesthetic preferences of the homeowner
- and the size of open areas within the building
- the type of extreme weather conditions prevalent in the area where the home or building is being built.
Many home builders order roof trusses from a manufacturer and have them delivered to a building site because building roof trusses is labor intensive and prefabricated roof trusses save time and money. If delivery to an area is a problem, or if the building design calls for a specific type or size of truss that is not readily available, the trusses may have to be built on site.
So when considering roof trusses for your home, they should not be chosen based on the looks alone. An experienced architect or engineer usually helps to make the determination on the roof truss design best suited to the building under construction. Someone with training specific to this area will be able to make the most use of the room in your home, giving it a spacious feel while still looking beautiful. A different type of roof truss design can be used in various areas of the home, making it possible to customize the look you want in different rooms, while still maintaining the same exterior appearance. While some roof trusses may be practical for the weather in a particular area, they may not be able to accommodate the desired design specifications for the building. Good architects and engineers consider both the building design and the stresses the roof will be subject to when choosing a truss design.
Building a shed can be a weekend project for someone who enjoys working in the house and yard. In order to create a sturdy shed, proper framing technique must be utilized. Building a shed may require a permit in some areas, so be sure to check before starting.
Roof trusses for sheds are simple to build and will create a strong roof for a small storage building or workshop. The trusses should be assembled once the floor of the building is complete.
Here are general guidelines on how to build and assemble roof trusses for a shed:
Measuring and Materials
Each truss requires two beams and one bottom cord, which are built from two by fours. The number of trusses needed depends on the length of the building. Trusses are usually installed every 16” on center. Measure the slope of the roof and multiply that by two, and then multiply that figure by the number of trusses needed. Multiply the width of the building by the number of trusses, and then add this to the first number. Add an additional 10% to cover board feet lost in cuts.
Cutting Rafters and Cords
The upper ends of the beams are cut at forty-five-degree angles. If the desired pitch of the roof is less than 45 degrees, it can be adjusted. Both ends of the bottom cord are cut at 45-degree angles to fit between the rafters and join them together. Triangular gussets made from 1/2” plywood are used to join the rafters and cords. Six gussets are necessary for each truss, and one of the angles on each gusset should measure 90 degrees, with the other two measuring 45 degrees. Gussets should extend inward past the joint of the rafters and cords and be flush with the edges.
Assembling the Trusses
Truss assembly should be done on the ground, first. Use the floor of the shed and align two rafters in a corner. Use a stop of 1” by 3” wood on each side of the corner to hold the beams in place. Make two more stops and install them flush with the bottom cord to keep it from slipping during assembly. Make sure the beams and cord fit snugly together. Using glue and screws or nails, attach a gusset to each of the three corners of the truss. Turn the truss over and attach gussets to the other side.
Installing the Trusses
The trusses are installed after the walls are framed and sheathed. One truss is attached with screws to both the front and rear walls of the building, and if the walls were framed 16” on center, one truss should attach at each upright in the wall. It is important to make sure the trusses are plumb (perfectly vertical) when attaching them to the frame to avoid gaps and weaknesses. When the roof sheathing is attached to the trusses, they should again be checked for whether they are still plumb.
It is not difficult to build roof trusses for sheds since the area of a shed is small and a simple design can provide adequate strength. Larger structures require designs that are more complex because larger buildings have greater stresses created by compression and tension. The principle of using triangles to distribute the stresses evenly is constant in every truss design.