Safety decals, Chapter 3 safety decals, Roof damage warning and disclaimer – Grain Systems Bin Accessories PNEG-1884 User Manual
Page 11: Caution
 
PNEG-1884 Special 90' Externally Stiffened 2 Ring Door for Use with Enhanced Stiffeners
11
3. Safety Decals
Roof Damage Warning and Disclaimer
Excessive vacuum (or pressure) may 
damage roof. Use positive aeration 
system. Make sure all roof vents are 
open and unobstructed. Start roof 
fans when supply fans are started. 
Do not operate when conditions exist
that may cause roof vent icing.
DC-969
CAUTION!
The manufacturer does not warrant any roof damage caused by excessive vacuum or internal 
pressure from fans or other air moving systems. Adequate ventilation and/or “makeup air” 
devices should be provided for all powered air handling systems. The manufacturer does not 
recommend the use of downward flow systems (suction). Severe roof damage can result from 
any blockage of air passages. Running fans during high humidity/cold weather conditions can 
cause air exhaust or intake ports to freeze.