5.2 Securing C-Channel Asphalt Roof (Shingles)
C-channel is fixed to roof rafters using 5” x Ø3/8” corrosion-resistant (galvanized) lag-bolts. Lag-bolts
must be centered in rafters since they carry weight of collector array. If rafter position cannot be
adequately determined or if lag-bolts cannot be centered in rafters, an alternative mounting method
may be used:
•
4” x 4” blocks cut to rafter spacing can be fixed between rafters. Lag-bolts can be screwed
into 4” x 4” blocks. This may facilitate installation as distance between peak and blocks may be
measured and transferred to exterior.
•
Metal or wood (2” x 4” min.) spanners may be fixed horizontally across rafters. C-channel can
then be secured with bolts or threaded rods (Ø3/8”) and lock-nuts instead of lag-bolts (Fig.
5.2.1). Spacers should be used between roof board and spanner to limit bowing and flexing of
roof sheathing and spanner.
•
Holes can be drilled immediately next to rafters and J-bolts or U-bolts (Ø3/8”) and locknuts used
to secure C-channel to rafters (Fig. 5.2.2).
Fig. 5.2.1 – C-channel secured to spanner.
Fig. 5.2.2 – C-channel secured to rafter with J-bolts and U-bolts.
Solar Collector
Installation Manual
13
Module 4
Summary of Contents for EWRA1
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