A metal roof must also allow for some overlap on each side of the panels which will reduce the effective width of the panel.
Roof truss spacing for metal roofing.
Install the roofing screws vertically along each rib in the panel.
Typically pole barn style buildings in my area have bays distance between trusses of 5 feet to 12 depending on pitch insulation and height.
This is most likely the standard size that you will find on pre made roof trusses.
Metal roofs and pole buildings.
With this design change roof trusses could be placed 12 feet apart making it possible for roofs to support the loads to which they would be subjected.
Most are spaced between 18 26 inches apart.
Be sure the larger edge is laid so that the small edge of the next panel will overlap it.
Pullout values decrease if the fasteners protrude completely through the purlins.
Wider panels allow for greater spacing between rafters.
Align the first metal roofing panel so that it overlaps the edging by 1 2 to 3 4 of an inch and is square to the roof.
The trusses should be a little longer than the exact width to allow for overhang and you will need sufficient trusses to mount across the length.
Depending on the complexity of your free computational tool it may require you to enter details about rafter spacing usually 16 on center bridge type height and board size.
I ve had roof truss manufacturers try to convince me it is impossible to place wood trusses at spacings of over every 4 feet.
Truss spacing for metal roof.
If purlins are laying flat on top of the truss 5 or 6 feet is the max on 2x4 s edge up can go to 12 feet or more.
Although the standard spacing of roof trusses may be the same as that of rafters with 24 inch spacing being a common option the design of a truss may allow for the use of a lower grade of lumber than would be required for rafters with comparable spacing and span.
Place the first screw.
Typical standard the typical standard for the spacing on the roof trusses is 24 inches.
Kiln dried softwood is recommended for purlins or decking pine fir hemlock and spruce.
It all comes down to engineering.
Typical roof truss spacing means that they are usually about 24 inches from centre which means at the centre of one truss there will be a two foot gap or twenty four inch gap until the centre of the next truss.
Their defense is our engineers will not allow us to.
Rafter spacing is based on the width of the metal roofing panels.
Putting the trusses into place.
As most building these days are using those pre made trusses on the roof 24 inches become the main size for any roofing construction when it comes to its truss installation.