|Bad alternative to installing plywood *
||Typical spaced sheathing
|* The space sheathing on the left is typical, just like the picture on the right — EXCEPT instead of installing plywood over the boards, they put boards between the spaced/skip sheathing. This is one of the ultimate, supreme Cowboy rodeo ripoff tricks that robs property owners of their hard-earned money!
Spaced or ‘skip’ sheathing is installed on roofs when wood shakes or shingles are used as the roofing material. This sheathing allows the wood to ‘breathe’. (Occasionally you see shakes over plywood but rarely. Plywood is not the correct deck for wood roofs, as the roofing and the plywood will fail prematurely due to moisture buildup.)
Switching from a wood roof to a composite shingle roof requires the installation of a solid deck, preferably real plywood and not OSB (waferboard).
Shown above left is a classic cowboy roofer ripoff trick where they installed boards between the spaced sheathing! Look at the wide gaps all over and note that a significant percentage of nails will not hit solid wood. Hand nailing can avoid this failure to hit solid wood, but with air nailers (which 98% of roofers use), the roofer cannot ‘feel’ whether the nails are hitting solid wood. This is one of many reasons why hand nailing is far superior to air nailing.