Table of Contents
What determines the spacing of purlin?
When positioned, roof purlins should be spaced no further than 1.2 metres apart when using sheeting with a thickness of 0.7mm, and 1 metre when using 0.5mm sheeting. Exact requirements will vary, but as a rough guide, this is a good rule of thumb to follow.
What factors influence spacing of trusses?
Trusses are usually spaced at regular intervals, typically 600 mm, 900 mm or 1,200 mm apart. The spacing depends on the mass of the roofing material and local practice. A range of truss types can be configured to attain different shapes.
What is the spacing on trusses?
Roof trusses should be 24” apart, on center. Trusses are allowed to be closer together, at either 12” or 16” on center, but building codes allow for 24” on center spacing without using heavier duty fasteners for truss to wall connections.
What is the standard spacing of purlins?
The spacing of purlins on roofs and girts on wall is usually 4 to 6 ft. Numbers 20 and 22, U.S. Standard gage, are generally used for roofing; No. 24 for siding.
What is the spacing for purlins on a metal roof?
The purlin are ultimately used to fasten the roof steel providing a diaphragm effect, along with the siding, when properly engineered and installed. Spacing is typically 24″ on center in low snow loads and is reduced based upon truss span and snow load.
How far apart can rafters be spaced?
But they do tend to space rafters in one of several industry-standard increments, typically either 12, 16 or 24 inches apart. These spacing intervals are measured “on center,” meaning that the measurement is taken from the center of one rafter’s horizontal surface to the center of the next rafter.
How do you attach purlins to metal trusses?
ADDING PURLINS Metal zee purlins should overlap on top of a truss. They should be placed on the outside of the truss clip with the bottom leg of the zee pointing toward the sidewall of the structure. The outermost truss clip will need to be adjusted for a vertical alignment.
How do you place purlins?
Lay the first purlin at the ridge of the roof down to the chalk line beginning at either corner. Fasten the purlin with 16d common nails into each vertical rafter. Insert two equally spaced nails into the rafter. The rafters are generally spaced every 16 inches on center.
How far apart should purlins be on a pole barn?
24”
On a typical post frame building, the purlins will be spaced no more than 24” on center. Not only are purlins vital in your post frame building’s structural integrity, but how they are secured is vital as well.