IB Insulation - Mechanically Attached

When installing an insulated mechanically fastened roof, the insulation is to be preliminarily fastened only. Set insulation over the substrate, taking care to fit uniformly and closely together. Offset board joints a minimum of 12" in one direction from the preceding course. Fill any gaps greater than 1/4" with matching insulation material. For mechanically attached roof membranes, secure the insulation using the appropriate fastening pattern for your board size. For a 4 X 8 board, measure in 12" from each corner in both directions and set the insulation plate. Then, place a plate equally spaced between and in line with the corner plates on the top and bottom rows.