Specifications

www.aetsolar.com Open Loop / PV - Page 8
There are three acceptable ways to secure the collector mounting brackets to the roof.
1. Spanner Mounting
2. Lag Bolt Mounting
3. J-Bolt Mounting
SPANNER MOUNTING
In spanner mounting after the brackets are positions on the chalk line, a 3/8” hole is drilled between the
rafters. An aluminum flashing is positioned over the hole where the top of the flashing is extended up
under the shingle above the 3/8” hole and extends down over it. Caulk is applied between the flashing
and the roof. The bracket is then positioned over the 3/8” hole using sealant between the bracket and the
flashing. A piece of 3/8” all-thread is then inserted through the hole. A washer and nut secures the all-
thread to the bracket (be sure the seal underneath the washer and on top of the nut). The all-thread rod
should extend about 4” below the roof rafters. Drill a 3/8” hole in a 2 x 4 and insert the all-thread rod
through it. The 2 x 4 should span 2 rafters. With a washer and double bolt secure the all-thread to the 2 x
4. Tighten down until the bracket is tightly secured to the roof. Be careful not to over-tighten and bell out
the roof underneath the bracket. (See Figure 6)
Figure 6. Spanner Mounting
LAG BOLT MOUNTING
In lag bolt mounting you must locate the center of the rafters along the top and bottom chalk lines. One
method is to have one man on the roof and another in the attic. Using a hammer the man on the roof can
tap the roof and determine where it is denser sounding. The roof man can drill a pilot hole while the attic
man helps with distance corrections. Then the attic man can call of the distance to the next rafter while
the roof man drills corresponding pilot holes. Flashing the brackets is done as previously described.
Secure the brackets to the roof using a ¼” x 3” stainless lag screw, a flat washer, and a lock washer
(Figure 7).