The "36" refers to the width of the deck sheets. The "4" is the number of welds per sheet width at each support. That leaves one weld each end and two in the middle.
Thanks. Therefore, the fasteners at the edges will be superimposed on the adjacent sheet...and so on... therefore the spacing is 12" o.c. for 36/4 pattern...(I was thinking originally at joints we would need 2 welds...
You're welcome, of course. I could have just said "12" but I thought you might not get what the pattern designation means and wanted to help a little further. If you have a Vulcraft steel deck catalog handy, turn to page 68. They have the weld locations for different patterns drawn. Looking at 1.5-inch type "B" deck and knowing that the flutes are 6 inches apart, you can see that a 36/4 pattern means a weld every other flute, or 12" o.c.