INSTALL THE BLOCKING BEHIND THE ROOF:solar cell

1. Blocking transmits the solar collector loads to the rafters and provides something solid to screw the
lag bolts into. Do not just lag the solar panels to the plywood sheathing; it is not acceptable. If
blocking can not be installed (as in a retrofit situation), the lag bolts must be drilled directly into the
rafters, or something else solid. Mounts provided by Radiantec can slide along the top and bottom
edges of the solar collec tor so that mounts can be installed directly into the rafters.
2. Blocking should be installed whenever possible because the collector array will be more attractive if
the mounts are spaced evenly and the rafters can be difficult to locate exactly.
3. The blocking should be close fitting and square. They may be 2”x 4”or 2”x 6”, and they can be
installed with the flat side up (towards the plywood). It will be easier to hit them squarely, and they
will be just as strong. They must be securely nailed with 16d nails or better.