Shed Roof Building Basics

If you’re building a shed, part of the job is building a shed roof. It can seem like a challenging task but it’s really not that complex. By breaking it down into stages, it becomes quite simple. If you’ve managed to build the rest of the shed, you’ll be able to build the roof of the shed quite easily.

Creating a Gable

The first to do in order to build a shed roof is to create a gable. Start by putting beams as a frame on the top of the walls of the shed. The corners need to be mitered and the beams should be nailed and glued in place. Make these beams a little wider than the walls of your shed. Now, measure along the short sides and make a mark in the exact middle. This is where you will put the post for your gable.

This needs to attach squarely to the beam; use a level to ensure it goes up at 90 degrees. The height of this beam will be the height of your gable. It should end with a 45 degree mitered corner facing into the shed. You need one of these beams at each end. Measure and cut a beam for the length of your gable. Miter the corners and fit into place between the beams using glue and nails


The rafters of the shed roof are the beams that go from the ridge beam to the walls of the shed. They should be spaced between 10 inches and 20 inches apart and you need an equal number of rafters on each side of the ridge beam. They should extend down at an angle of 45 degrees with a notch cut out to rest on the bream on top of the long walls. The ends slould extend beyond that by a distance of 6 inches to 12 inches.

To do this, miter the top of the beam so it fits at 45 degrees against the side of the ridge beam. Measure where the beam will cross the top of the shed walls and cut out a piece as wide as the beam on top of the walls with the same depth. It will look as if you’ve removed a triangle from the wood. Nail each beam in place.

Plywood and Tarpaper

Now you’re ready to put on the plywood to cover the shed roof. It will be in sheets that are 4 feet by 8 feet and you’ll need to cut some sheets to achieve full coverage. Screw into place on the rafters so the plywood is firm. The plywood should be pushed high at the ridge so sheet edges from either side touch. Nail on tarpaper to cover the plywood. This will keep water off the wood and stop it rotting.


Shingles need to be nailed on from the edge of the roof, moving up in layers to the ridge. Each layer should overlap the one below it. At the ridge, you’ll should use shingles that fit over the top to stop water from entering.