Structural Loads are stresses to structure from external or internal forces.
• Dead loads are gravity loads that are constant throughout the structure’s life. These include equipment such as fans, heaters and plants suspended from the frame.
• Live loads are temporary, such as snow loads and wind loads.
• Snow loads determined by factors influencing snow & ice accumulation on the structure. Snow loads vary considerably by geographic location. Ask your local bldg. dept. for snow load in your area. ( 12 inches of light, fluffy snow or 2 to 4 inches of heavy, wet snow = about 5 lbs per sq. ft.)
• Wind loads can come from any direction but usually hit side walls at a perpendicular angle.
Figures are in lbs. per sq. ft.
| Wind Speed | 85 mph | 90 mph | 100 mph | 120 mph | 130mph | 140 mph | 150 mph | 160 mph |
| 18 | 20 | 25 | 36 | 43 | 48 | 56 | 85 |
Wind speeds up to 90 mph: Screws with 3/4″ sealing washers are to be set at corners of glazed areas and every 1 ft. on-center.
Base & Cap System: Screws provided with system to attach Base to frame and Cap to Base. The Base, Cap and Corner receive screws at ends of each Trim piece and every 1 ft. on center. In winds of 110 mph and over screws to be every 10″. In winds of 125 mph and over screws to be every 8 inches. In winds of 135 to 150 mph screws to be every 6 inches. In winds over 110 mph always consult with engineer to receive a stamp and bldg. dept. approval. For placement of screws in body sheet see Polycarb. Position & Attach.
• Combination loads are common. For example, a snowstorm may include high winds.
• Blocking, Purlin or Girt placement for wind and combination loads: If bldg. dept. says design for a 45 lb. snow load & 90 mph wind, snow will effect the roof with a 45 lb. load and wind will effect roof with 20 lb. load. To safely design your roof framing, take the 45 lb. snow load, add 20 lbs. for effect the wind may have on the roof. Design for a 65 lb. load.
Important Hurricane Zone Notes: Above wind load figures are provided by polycarbonate manufacturer, and are only provided as a general guideline. Fastening recommendations are also a general guideline. At design time it is the customers responsibility to receive an engineers stamp and approval from your local bldg. dept. We take no responsibility for the final design and installation of our products in hurricane zones, but will work closely with customers and their architects and engineers to receive bldg. dept approval. It is the responsibility of the bldg. dept. inspector to approve project after installation.
Note on Bronze Polycarbonate and Aluminum: Please be advised that Bronze gets substantially hotter than White/Opal Poly. or White Aluminum, or Clear Poly or Clear Satin Anodized Aluminum. The end result is greater expansion and contraction, and increased pressure on attachment screws, compromising attachment to frame.
This effect is increased in hurricane zones, which are inherently in hot climate areas.