How To Shape Purlin For Corrugated Roof

Setting corrugated metal roof purlin spacing in a proper distance is an important part of the entire process.

How to shape purlin for corrugated roof.

Lay the first purlin at the ridge of the roof down to the chalk line beginning at either corner. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. Apply front and back panels similarly to side walls. Cut to fit pitch of roof and around vent.

Overlap roof panels one corrugation away from prevailing wind and nail to rafters starting from one end. Corrugations should run in a straight line between the highest and lowest points and at a right angle to the purlins the intermediate supports. 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. Purlin spacing should suit the end laps required for the size of sheet to be used.

The overlaps ends and sides depends upon the sloop of the roof see below. The distance lengths are often based on the roofing panels size. Corrugated sheet roofing material is widely available and easy to use. Snap a chalk line horizontally across the roof two feet down from the top.

The decking is sized to resist the bending caused by these loads. Install vent as close to roof peak as possible. To identify whether yours is the earlier or the latter type look for the end of the rails and check whether the shapes mimics the shape of letter c or letter z. Insert two equally spaced nails into the rafter.

Corrugated metal deck and siding is used for roofs and walls respectively to span between purlins for roof loads or between girts for wind loads. Meanwhile there are two kinds of purlin span for metal roof based on the shapes which are the c purlins and z purlins. Roof decking is often also used as a diaphragm to transfer wind or seismic loads to the lateral bracing system below. The rafters are generally spaced every 16 inches on center.

Fasten the purlin with 16d common nails into each vertical rafter.