1x4 Board Spacing Under Metal Roof

Do all roofing projects require purlins.

1x4 board spacing under metal roof. When putting on a metal roof how far apart do you space the furring strips. The roofing is manufactured in panels that. 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. To determine how far apart to set rafters measure the width of the metal panel and then the width of the first hill and valley of the panel.

5 4 x 4 slats are acceptable decking still not if just 4 oc supported 24 oc if hitting nail penetrations full 1 nail penetration into 2 x structure stock on panel sides. Metal roofing panels rated for architectural use attached to purlins horizontal pieces of wood or metal fastened to roofing trusses are structurally sound when installed according to your roofing manufacturer s instructions and local building codes. Installing wood stripping under a tin roof. Allowable gap between firring strips relates to the ability of the roofing material to resist buckling or crumpling under snow wind or walking loads.

If an open grid framed roof or widely spaced old solid roofing planks as the sheathing it is important to tightly stretch this so it does not sag down and hold water between the framing roof sheathing boards and the metal roofing obviously far better to put down a solid sheet sheathing first when doing a reroof in that sort of situation. Wider panels allow for greater spacing between rafters. Regardless 1x4 decking slats aren t acceptable. 2x4 s on flat 24 oc is what scott s pdf said as a minimum even if overlay on existing decking and old roof covering.

The spacing of your purlins depends on the expected snow and wind load. Whether you are looking to install a metal roof on a shed or a house it s important to know the difference in the various types of metal roofs available. A metal roof must also allow for some overlap on each side of the panels which will reduce the effective width of the panel. We do recommend it however.

The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. Let s take a look at the most common types of metal roofs for houses.