5 square timber a bit flimsy.
Shed roof timber size.
That is your span your actual rafter length would be longer with an overhang and extra length for the cuts.
The shed roof framing design will include the type of shed roof finish.
Don t forget to cut the ends of each board to the appropriate angle to allow them to fit together at the peak.
For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2.
This means the example porch would need a 6 inch by 8 inch beam.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.
Traditional shingles clay wood sheet metal or eco living.
Time involved and the cost.
This tells you the size of the beam needed to support the porch s roof.
If you re planning on building a gable roof with a pitch of 4 12 for a shed that s 200 inches 510 cm wide your rafter boards would need to be 105 3 inches 267 cm long on each side.
The type of support.
There are many design plans available to download and videos online to guide you.
In the example d calculates to 7 75.
As a general rule roofs that have a high human occupancy rate should be framed with rafters every 16 structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
Calculate the initial value for d then round it up to the nearest inch.
This is the distance between rafter centres.