Spacing For Screw Down Snow Guards on Exposed Fastener Metal Roofs
Screw Down Pad Style Snow Guard Spacing Guidelines
In parts of the world that receive winter precipitation, snow and ice on glossy coated metal roofing can create an extremely dangerous avalanche condition. A properly installed snow guard system can mitigate this condition. Our approach to proper placement involves an overall spacing throughout the entire roof area to keep snow and ice from shifting initially. Once frozen precipitation loses its grip on a metal roof and begins a down-hill slide, everything in its path will be destroyed. A single row of guards placed along the eave or gutter edge of the roof is not always enough protection against this dangerous condition. An evenly distributed snow load will preserve the long-term integrity of the actual structure, metal roof and snow retention system. Isolating snow guards on partial roof sections such as just over doorways or roof vents is not recommended.You can use the snow guard spacing calculator or select your pitch below to get a general spacing guideline. All upper roof areas must have a snow retention installed before installing snow guards on a lower roof. This page should only be used only as a quick reference guide for estimating snow guard quantities and placement on roofs with up to 45 PSF ground snow load. Always consult with an architect or engineer for recommended snow guard placement for your project.This spacing guideline does not account for snow shadows, drifting or unseasonable conditions. If your ground snow load exceeds 45PSF please fill out ourQuote Request Formfor the heavy duty SnoBar/ColorBar systems. All screw down pad style snow guards compatible with this spacing guideline are for sale at the bottom of this page.
Please Pick Your Roof Pitch Below
| 1/12 - 2/12 Pitch | 3/12 - 4/12 Pitch | 5/12 - 6/12 Pitch | 7/12 - 8/12 Pitch | 9/12 - 12/12 Pitch |
1/2 - 2/12 Roof Pitch
Eave Strut: Horizontal beams that are installed between the roof rafters or trusses and the top plate of the exterior wall.
Panel: Snow guards staggered in every panel flat
Pitch:1/12 to 2/12 pitch.
Use: Staggered pattern of snow guards every 25 feet going up the roof.
Snow load: Up to 45 PSF ground snow load.
If your metal roof panels are only mounted on top of purlins or firing strips, the snow guards must be screwed into the purlins or firing strips. If your metal panels are placed on decking, make sure your decking is adequate to secure the snow guards. Place your first staggered pattern of snow guards in, every other panel flat, along the Eave Strut (1 foot from the bottom edge on decking). Then move up to the first purlin above the eave strut (2 feet up from the bottom edge on decking) and place a snow guard in the center of each valley, alternating from the row below to create a staggered pattern that spans across the entire roof. Move up the roof every 25 feet and repeat the same staggered pattern of guards across the entire roof. Do not exceed 25 feet vertically between staggered patterns of snow guards. When possible, always attempt to divide the roof areas into equal sections, with equal distance between patterns of snow guards. Please note that our spacing is based on metal panels attached directly to a flat decking surface such as plywood or OSB. If your metal roof panels are attached to horizontal purlins (strips of wood that leave an air gap between the roof structure and the panels) then you will need to modify the staggering of the rows to ensure that your fasteners are getting into solid structural wood. Please ensure that your purlins and/or decking material is in good serviceable condition and can withstand the snow loads that will be transferred to it by installing a snow retention system. All upper roof areas must have snow retention installed before installing snow guards on a lower roof. Never isolate areas of snow guards such as just over doorways or vent pipes.
3/12 - 4/12 Roof Pitch
Eave Strut: Horizontal beams that are installed between the roof rafters or trusses and the top plate of the exterior wall.
Panel: Snow guards staggered in every panel flat
Pitch: 3/12 up to 4/12 pitch.
Use: Staggered pattern of snow guards every 20 feet going up the roof.
Snow load: Up to 45 PSF ground snow load.
If your metal roof panels are only mounted on top of purlins or firing strips, the snow guards must be screwed into the purlins or firing strips. If your metal panels are placed on the decking, make sure your decking is adequate to secure the snow guards. Place your first staggered pattern of snow guards in, every other panel flat, along the Eave Strut (1 foot from the bottom edge on decking). Then move up to the first purlin above the eave strut (2 feet up from the bottom edge on decking) and place a snow guard in the center of each valley, alternating from the row below to create a staggered pattern that spans across the entire roof. Move up the roof every 20 feet and repeat the same staggered pattern of guards across the entire roof. Do not exceed 20 feet vertically between staggered patterns of snow guards. When possible, always attempt to divide the roof areas into equal sections, with equal distance between patterns of snow guards. It is highly recommended to screw into a purlin or structural support. This spacing recommendation can be slightly adjusted to accommodate the locations of the structural support and purlins under the metal roof sheets. Please ensure that your purlins and/or decking material is in good serviceable condition and can withstand the snow loads that will be transferred to it by installing a snow retention system. All upper roof areas must have snow retention installed before installing snow guards on a lower roof. Never isolate areas of snow guards such as just over doorways or vent pipes.
5/12 - 6/12 Roof Pitch
Eave Strut: Horizontal beams that are installed between the roof rafters or trusses and the top plate of the exterior wall.
Panel: Snow guards staggered in every panel flat
Pitch: 5/12 up to 6/12 pitch.
Use: Staggered pattern of snow guards every 10 feet going up the roof.
Snow load: Up to 45 PSF ground snow load.
If your metal roof panels are only mounted on top of purlins or firing strips, the snow guards must be screwed into the purlins or firing strips. If your metal panels are placed on the decking, make sure your decking is adequate to secure the snow guards. Place your first staggered pattern of snow guards in, every other panel flat, along the Eave Strut (1 foot from the bottom edge on decking). Then move up to the first purlin above the eave strut (2 feet up from the bottom edge on decking) and place a snow guard in the center of each valley, alternating from the row below to create a staggered pattern that spans across the entire roof. Move up the roof every 10 feet and repeat the same staggered pattern of guards across the entire roof. Do not exceed 10 feet vertically between staggered patterns of snow guards. When possible, always attempt to divide the roof areas into equal sections, with equal distance between patterns of snow guards. It is highly recommended to screw into a purlin or structural support. This spacing recommendation can be slightly adjusted to accommodate the locations of the structural support and purlins under the metal roof sheets. Please ensure that your purlins and/or decking material is in good serviceable condition and can withstand the snow loads that will be transferred to it by installing a snow retention system. All upper roof areas must have snow retention installed before installing snow guards on a lower roof. Never isolate areas of snow guards such as just over doorways or vent pipes.
7/12 - 8/12 Roof Pitch
Eave Strut: Horizontal beams that are installed between the roof rafters or trusses and the top plate of the exterior wall.
Panel: Snow guards staggered in every panel flat
Pitch: 7/12 up to 8/12 pitch.
Use: Staggered pattern of snow guards every 6 feet going up the roof.
Snow load: Up to 45 PSF ground snow load.
If your metal roof panels are only mounted on top of purlins or firing strips, the snow guards must be screwed into the purlins or firing strips. If your metal panels are placed on the decking, make sure your decking is adequate to secure the snow guards. Place your first staggered pattern of snow guards in, every other panel flat, along the Eave Strut (6" from the bottom edge of the decking). Then move up to the first purlin above the eave strut (1 foot up from the bottom edge on decking) and place a snow guard in the center of each valley, alternating from the row below to create a staggered pattern that spans across the entire roof. Move up the roof every 6 feet and repeat the same staggered pattern of guards across the entire roof. Do not exceed 6 feet vertically between staggered patterns of snow guards. When possible, always attempt to divide the roof areas into equal sections, with equal distance between patterns of snow guards. It is highly recommended to screw into a purlin or structural support. This spacing recommendation can be slightly adjusted to accommodate the locations of the structural support and purlins under the metal roof sheets. Please ensure that your purlins and/or decking material is in good serviceable condition and can withstand the snow loads that will be transferred to it by installing a snow retention system. All upper roof areas must have snow retention installed before installing snow guards on a lower roof. Never isolate areas of snow guards such as just over doorways or vent pipes.
9/12 - 12/12 Roof Pitch
Eave Strut: Horizontal beams that are installed between the roof rafters or trusses and the top plate of the exterior wall.
Panel: Snow guards staggered in every panel flat
Pitch: 9/12 up to 12/12 pitch.
Use: Staggered pattern of snow guards every 5 feet going up the roof.
Snow load: Up to 45 PSF ground snow load.
If your metal roof panels are only mounted on top of purlins or firing strips, the snow guards must be screwed into the purlins or firing strips. If your metal panels are placed on the decking, make sure your decking is adequate to secure the snow guards. Place your first staggered pattern of snow guards in, every other panel flat, along the Eave Strut (6 inches from the bottom edge of the decking). Then move up to the first purlin above the eave strut (1 foot up from the bottom edge on decking) and place a snow guard in the center of each valley, alternating from the row below to create a staggered pattern that spans across the entire roof. Move up the roof every 5 feet and repeat the same staggered pattern of guards across the entire roof. Do not exceed 5 feet vertically between staggered patterns of snow guards. When possible, always attempt to divide the roof areas into equal sections, with equal distance between patterns of snow guards. It is highly recommended to screw into a purlin or structural support. This spacing recommendation can be slightly adjusted to accommodate the locations of the structural support and purlins under the metal roof sheets. Please ensure that your purlins and/or decking material is in good serviceable condition and can withstand the snow loads that will be transferred to it by installing a snow retention system. All upper roof areas must have snow retention installed before installing snow guards on a lower roof. Never isolate areas of snow guards such as just over doorways or vent pipes.
Disclaimer
This page may be used only for the purpose of developing plans, specifications, and/or approval drawings for construction projects utilizing only IceBlox, Inc. manufactured or distributed products and components. It is to be used only as a quick reference for estimating snow guard quantities and placement on roofs with less than 45 PSF ground snow load.
IceBlox Inc., d.b.a SnoBlox-Snojax, referred to hereafter as IceBlox, Inc., or any subsidiary brands or companies, is not responsible for estimates or purchases resulting from the erroneous or improper use of this page orsnowguardspacingtool.com.
The user shall determine the suitability of the product for its intended use and assumes all risks of its use or handling. In regards to spacing guidelines, quotations and or layouts, Iceblox, Inc. will not be held liable for incorrect material quantities not recommended onsnowguardspacingtool.comand/or SnoBlox-Snojax.com
Screw Down Snow Guard Spacing Frequently Asked Questions(FAQs)
Each of our screw-down, polycarbonate snow guards requires two screws. You will find pre-drilled holes or starter points near each guard's face. Our SnowCatchers feature three holes, 2 of which are near the face and required for attachment. A 3rd hole, at the opposite side of the base, is primarily used as a hanging point if powder coated or you choose to paint them. This hole can also act as an additional attachment point. The SnoCleat PBR and SnoCleat 2.67 both require at least three screws but can use up to 6 per guard.
Most of our polycarbonate pad-style snow guards come with molded starter points. Our screws are self-tapping and able to drill through this material with ease. You may pre-drill the guards if you prefer, but it is not a requirement. The Snojax 1, Stainless SnowCatchers, aluminum SnoCleat PBR, and the aluminum SnoCleat 2.67 come with predilled holes.
Most of our screw-down snow guards can attach with the two different screws that we have available currently. The Master Gripper is a 2" long #14 self-tapping screw for use with wood purlins, whereas the Master Driller is a 1.5" #14 self-tapping screw for use with metal purlins. These fasteners are case-hardened carbon steel, are silver in color, and feature neoprene washers. The SnoCleat 2.67 uses a 3" screw as it straddles the high ribs of the panel. Depending on whether or not there is insulation under the panels, longer screws may be necessary.
NovaFlex MR150's neutral curing, ability to cure in wet conditions, and low-temperature tolerance make it our sealant of choice. With our polycarbonate snow guards, we recommend applying liquid sealant liberally over the entire base, filling in any gaps between the guard and the panel. Once applied, screw the snow guards down and run a gloved finger around the guard to seal in the perimeter and remove excess from the roof surface. With our metal SnowCatchers, SnoCleat PBR, and SnoCleat 2.67, a die-cut foam gasket is included for use in place of liquid sealant. In some cases, however, our customers will still run a bead of sealant around the pads to provide additional protection. This step is optional.
An adequately installed snow guard system should result in zero roof leaks. Make sure that you are using screws with neoprene washers and pairing them with either liquid silicone (for polycarbonate snow guards) or a foam gasket (for metal snow guards). Many people elect not to make any new roof penetrations for snow guards. As such, they will install a glue-down snow retention system with the Surebond SB-190 adhesive.
Approximately 10 of our larger polycarbonate snow guards and 20–25 of our smaller ones can be installed with the Novaflex MR150 sealant and screws. Please be aware that this may change depending on the user's application. Novaflex MR150 is a sealant and not an adhesive. You shouldn't use it to glue down polycarbonate snow guards in place of Surebond SB-190.
All Screw Down Pad Style Snow Guards