Spaced sheathing also called skipped decking refers to the construction details of the substrate which the cedar gets nailed to and thus secured to your home.
Skip sheathing metal roof.
The structural panels act as a diaphragm to transfer lateral loads at the plane of the roof to the walls.
When installed correctly wood shingles are rigid and allow the roof to be walked on.
Sheathing should be a minimum of 19 32 inch thick.
Never attach roof sheathing with staples.
Metal tile and shingle roofing may also be applied to solid sheathing.
By installing skip sheathing as the roof deck the spaces between the boards allow the wood shakes to breathe so that they dry more evenly after being soaked in the rain limiting warping.
Most you see on homes and many commercial building is non structural metal roofing and needs to be on solid sheathing.
For economic and structural lateral load reasons solid sheathing is almost always plywood osb or other structural panels.
Typically 1 4 or 1 6 boards of wood are installed with a 3 5 maximum space between each board directly over the roof rafters or in a cold roof system over the plywood deck.
This does not apply in environments with wind driven rain and snow however.
On metal frame building and the like you will likely see structural metal roofing installed on purlins that is what those 1x4 are purlins and those metal roofing panels are rated for that type of installation.
Osb or plywood over skip sheathing makes for a much stiffer roof deck resists problems with expansion better and obviously doesn t require all the hassle of removing it.
8d ring shank nails should be used instead.