Snow catchers prevent snow from sliding off metal roofs. The weight of the falling snow can cause damage to property, such as landscaping under the roof. This is especially important above sidewalks and walkways located close to the building, where falling snow can pose a threat to pedestrians. A variety of snow and ice catchers are available for different climates with different snowfall amounts. Speak with a roofing specialist to determine which are appropriate for your location.

Calculate Quantity of Materials Required

According to the M.M. Products, Inc. online publication, "Installation Procedures for Glacier Snow Guards," to install snow catchers on a metal roof, first count the number of panels on the metal roof. Calculate the pitch of the roof by holding the edge of a 12 inch level on the roof. Measure the distance from opposite bottom corner of the level to the roof in a vertical line. If the measurement is 8 inches, the pitch is 8/12 or 8 in 12. Multiply the number of panels by two for roofs with a pitch of 6/12 or less. Multiply the number of panels by three for roofs above 6/12. The steeper pitch requires an additional pair of rows of snow catchers. Measure the roof from eave to peak. If the roof is more than 30 feet, add an additional row of snow catchers for roofs 30 feet or more. Multiply the number of snow catchers by two for the number of screws and washers.

Placement of Snow Catchers

Starting from 16 inches from the eaves, or edge of the roof, install the first row of snow catchers on the center of the second panel from the edge of the metal roof. Install each snow catcher on this row on every other panel until reaching the opposite end. Install the second row of snow catchers 16 inches above the first row on the center of the first panel from the edge of the metal roof. Install each snow catcher on this row on the panels in between the first row. Install the third row of snow catchers 8 to 12 feet from the second row on every second panel from the edge of the roof. Install each snow catcher on this row on every other panel until reaching the opposite end. This row should be on the same panel as the first row. Install the fourth row of snow catchers 16 inches above the third row on the center of the third panel from the edge of the metal roof. Install each snow catcher on this row on the panels in between the third row. This row should be on the same panel as the second row. Install an additional row for roofs that are more than 30 feet from eave to peak.

Install Snow Catchers

The online installation guide from IceBlox, Inc., recommends the following procedure for cleaning the metal roof and applying adhesive, and screws if desired, for installation of snow catchers. Check the weather prior to installation. The temperature required for proper curing of most exterior adhesives is above 50 degrees for five days. Follow the manufacturer's recommendations for temperature and cure time on the adhesive label. Clean the area where the snow catcher will be attached with alcohol or xylol. Do not allow the alcohol or xylol to come into contact with plastic snow catchers. Apply a thick coating of adhesive to the snow catcher. Press it into position on the metal roof. This is all that is required--screws are not necessary, but the following step will improve performance for areas with a higher than average snowfall. Use the drill and screwdriver bit to install two screws with washers into two of the holes on each snow catcher.

Source:

Metal Roof Snow Guards: Snow Guard Installation Instructions

Copper Roofing Supply: Snow Guard, Snowguard Discount Warehouse

Copper Roofing Supply: Snow Guard Installation Instructions