Roofing Using 2x4

In bending 2 4 2 purlins would work at 12 on center however i personally would not want to walk on top of them.

Roofing using 2x4.

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. Access the roof using an extension ladder. Using the aggregate area of these simple shapes can yield a more accurate roof area to be used with the roofing material calculator.

Built on 4 12 pitch roof with 1 2 ply decking and shingles. The most common roofing materials used in the united states include shingles membrane roofing and ceramic tile all of which have different life spans. For this example a section of roof is 20 feet wide. Rafters to 2x4 with joist hangers.

The wider the roofing panels the greater spacing distance you should put. I put 2 2x4 joist about. One foot overhang so could say 11x16. There is a chance of damaging roofing sheets if you are failed to do so.

2x4 x8 feet boards. 60 pieces 2x4 x12 feet boards. Rafters are on 2 ft spacing. 5 pieces 2x4 x12 feet boards pressure treated.

Measure each section of the roof from side to side parallel to the line of the fascia board. 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. Front and sides will sit on deck on a 2x4 wall with studs 24 oc and screened in. 1 3 of the way from each in to keep it from spreading from snow load.

For roofs that won t experience heavy snow loads a gable roof can span up to 22 with 2 4 rafters. The metal roof purlins spacing must be done correctly within narrow tolerances. It s made 11 winters here and look like the day i finished it. The width of metal panels will determine the rafter spacing.

For roofs that will experience heavy snow or wind and will span the same distance use 2 6 rafters. 2 pieces 12 feet aluminum.