Building trusses on site is easily done for a shed.
Shed roof ridge beam.
Yes either a ridge board or a ridge beam is necessary and required by the building code where roof rafters meet at the the center of their span.
One collar tie would be enough in your case.
A proper beam would have a supporting post at each end.
Versa lam lvl size chart laminated beam span tables charts.
Determine your desired roof pitch.
The term pitch refers to the slope of the roof.
Here s a picture of a gable style shed using a ridge beam.
Lawriter oac 4101 8 01 roof ceiling construction.
Some shed rafters do not incorporate ridge beams either due to small size or lack of technical know how.
For example if the slope is 4 in 12 and the run is 12 feet the ridge beam height m will be 4 feet.
You don t need a ridge beam but you do need a way to keep the walls from spreading.
A ridge beam runs the length of the shed roof connecting every pair of rafters.
Determining the ridge beam height.
A simple gable shed roof is often built using 2 4 or 2 6 lumber for the rafters and 2 4 for the collar ties.
Now if you have done any looking around this site you ll quickly see that i am not a fan of using a ridge beam in shed construction.
However our instructions include making shed rafters with a ridge beam.
This can be accomplished with collar ties boards spanning the shed at ceiling height or with large gussets further up the rafter slope.
Look at it this way say 40 inch load at the ridge look at your 3 4 sheathed roof as a big 8 ft high 3 8 thick beam laid flat down to a 4 12 slope an eyeball number you better check shows that a less than 1000psi plywood would be sufficient with staggered middle edges and 2x6 rafters to keep em flat however you then have about 6000 pounds of lateral thrust at each end wall to deal with.
The difference between them is that a ridge beam is a structural member that bears half of the live and dead loads of the rafters on either side of it but a ridge board is not structural.
Framing in a ridge beam in shed roof construction is not hard.
The rafters are angle cut at the ridge end and notched with a birdsmouth where it meets the top plate of the supporting wall.
I always always build trusses.
Shedme shed roof rafter span.