The wider the roofing panels the greater spacing distance you should put.
Roofing using 2x4.
Front and sides will sit on deck on a 2x4 wall with studs 24 oc and screened in.
One foot overhang so could say 11x16.
5 pieces 2x4 x12 feet boards pressure treated.
60 pieces 2x4 x12 feet boards.
Without even running the calculations i would say there is a good chance the 2 4 purlins will not make the deflection criteria required for a roof framing member supporting steel.
Built on 4 12 pitch roof with 1 2 ply decking and shingles.
The metal roof purlins spacing must be done correctly within narrow tolerances.
2 pieces 2x4 x10 feet boards pressure treated.
Access the roof using an extension ladder.
Floor joist on 16 inch centers.
If you have a simple gable shed roof then using 2 4 rafters makes more sense unless you have a very large shed.
Rafters to 2x4 with joist hangers.
The width of metal panels will determine the rafter spacing.
Roof will be roughly 12 x 16.
Rafters are on 2 ft spacing.
For this example a section of roof is 20 feet wide.
A rough 2x4 had a lot more strength that a finished one.
2 pieces 12 feet aluminum.
For roofs that won t experience heavy snow loads a gable roof can span up to 22 with 2 4 rafters.
There is a chance of damaging roofing sheets if you are failed to do so.
1 3 of the way from each in to keep it from spreading from snow load.
In bending 2 4 2 purlins would work at 12 on center however i personally would not want to walk on top of them.
The most common roofing materials used in the united states include shingles membrane roofing and ceramic tile all of which have different life spans.
2x4 x8 feet boards.
I put 2 2x4 joist about.
Measure each section of the roof from side to side parallel to the line of the fascia board.