This frame supports and is hidden by a metal facia board.
Roofing roof framing plan c purlins.
The facia frame may also supports the soffit.
In traditional timber truss construction purlins rest on the principal rafters of the truss.
Metal roof purlins are installed horizontally under metal roofs.
Here is a closer look at common roofing terms.
Purlins are 2 by 4 feet and are installed much like metal roofing.
In small roofs purlins are inserted between the rafters and nailed through the rafters.
Engineered purlin metal mart offers a complete line of engineered purlin material.
Purlins are non pressure treated 1 x 4 x 12 lumber that is installed on to the roof in a specific layout pattern and screw pattern.
They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top.
For sake of discussion we will assume a minimal roof snow load of 20 psf pounds per square foot and a 4 12 roof slope.
We do recommend it however.
Metal c purlins are light in weight and perfect for simple span construction.
Dead load will be the actual weight of the roof steel and the roof purlins.
Purlins purlins are used in roof construction to support corrugated sheet metal if it is used or to support the sheathing of roofs framed with trusses.
Do all roofing projects require purlins.
Roof framing involves a lexicon all its own.
Galvanized cee purlins in steel construction the term purlin typically refers to roof framing members that span parallel to the building eave and support the roof decking or sheeting.
The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.
Includes illustrations that show roofs have hip rafters ridge boards jack rafters and more.
The cos of the purlin spacing is because the load on the purlins is vertical and the purlin spacing is with the run of the roof.
In large buildings where heavy trusses are used the purlins are continuous members that rest.
The steel purlins are in turn supported by rafters or walls.
When repairing or replacing a roof it pays to be familiar with these terms.
Under purlins were typically propped off internal walls.
For example an 8 x 4 under purlin would support the center of a row of 6 x 2 rafters that in turn would support 3 x 2 roof purlins to which the roof cladding was fixed.
Available in cee or zee shape red oxide primed or galvanized 16 14 or 12 gauge sizes from 4 up to 12 flange widths of 1 1 2 up to 4 cut to your specified lengths hole punching available load tables available for all material.
The purlins support the long span steel roofing but before the roof itself is put on a metal facia frame is installed around the perimeter of the roof.
They give added support to the roof and also provide a nailing surface for the end panels and drip edge.