9910045 RevF
October
2020
Appendix E: Ballast Blocks
PanelClaw does not provide the ballast blocks required to construct the system in accordance with
PanelClaw’s
Racking Construction Set
drawings. However, PanelClaw maintains a list of potential block suppliers across the country and this list is available upon request.
BALLAST BLOCKS FOR
ANY
BALLASTED ROOFTOP SYSTEM MUST BE MANUFACTURED TO RESIST FREEZE-THAW AS REQUIRED BY LOCAL
CONDITIONS
AND
TO MAINTAIN THEIR WEIGHT OVER THE LIFE OF THE SYSTEM. IT IS STRONGLY RECOMMENDED THAT INSTALLERS WEIGH
SEVERAL BLOCKS ON-SITE TO ENSURE BLOCK WEIGHTS MATCH THE WEIGHT OF THE BLOCKS SPECIFIED IN
PANELCLAW’S
RACKING
CONSTRUCTION SET DRAWINGS. BLOCK WEIGHT VARIANCES LISTED IN THE CHART BELOW ARE ACCEPTABLE.
Ballast Block Description
Nominal Weight
kg [lb]
Allowable Weight Variance
(+ or -) Kg [lb]
BLOCK, CONCRETE, 2"X 8"X 16"
6.6 [14.6]
0.45 [1.00]
BLOCK, CONCRETE, 3"X 8"X 16"
10.7 [23.6]
0.57 [1.25]
BLOCK, CONCRETE, 4"X 8"X 16"
14.8 [32.6]
0.68 [1.50]
BLOCKS WITH A WEIGHT VARIANCE GREATER THAN WHAT IS SHOWN IN THE CHART ABOVE MUST NOT BE USED.
FAILURE TO FOLLOW THESE PRACTICES MAY RESULT IN SYSTEM PERFORMANCE BELOW DESIGN CRITERIA AND/OR MAY CAUSE STRUCTURAL
DAMAGE TO THE BUILDING AND/OR ARRAY.
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