Commercial Gutter Guard Specifications: A Technical Guide for Australian Projects

Commercial gutter guard specifications need to account for much more than mesh aperture and total gutter length. Architects, builders and facility managers must consider the gutter configuration, adjoining roof profile, fixing method, drainage design, maintenance access and any project-specific bushfire requirements.

This is particularly important for internal box gutters. Because these gutters can sit within the building footprint, an obstruction or unresolved drainage problem may allow water to enter occupied, storage or production areas rather than simply overflowing beyond an external fascia.

Leaf Stopper provides different systems for different commercial roof and gutter configurations. COMGUARD™ is designed for internal box gutters, while DEKGUARD™ is designed for external gutters adjoining supported flat-based metal roof profiles. DEK-762™ is a separate system using profile-specific DEKAFast saddles.

This technical guide explains how to develop more accurate commercial gutter guard specifications without treating gutter protection as a substitute for hydraulic design, roof drainage capacity or ongoing inspection.

Scope of a Commercial Gutter Guard Specification

A commercial gutter guard specification should identify the complete system rather than using a generic note such as “provide metal gutter mesh”.

At a minimum, the documentation should identify:

• The gutter type
• The adjoining roof manufacturer and profile
• The required Leaf Stopper system
• The Mesh Shield type
• The mesh aperture and aluminium thickness
• The required Mesh Shield width
• The roof-side fixing components
• The wall-side or gutter-side fixing components
• The proposed access-panel locations
• Downpipes, sumps, rainheads and overflows that must remain accessible
• Colour and finish requirements
• Installation responsibility
• Inspection and handover requirements
• Any project-specific BAL, certification or approval requirements

Avoid Performance Guarantees the Product Cannot Control

The specification should not state that gutter guard will:

• Prevent every blockage
• Guarantee that a box gutter cannot overflow
• Increase the capacity of an undersized drainage system
• Correct insufficient gutter fall
• Clear downstream pipework
• Make gutters maintenance-free
• Automatically satisfy every BAL or building-compliance requirement
• Guarantee insurance acceptance

Gutter guard is one component within the broader roof-drainage and building-protection strategy.

Commercial vs Residential Gutter Guard

The same aluminium mesh options may be used across residential and commercial projects, but the roof and drainage configurations can be significantly different.

Commercial projects commonly involve:

• Large roof catchments
• Long internal box-gutter runs
• Parapet walls
• Multiple sumps and downpipes
• Wide-span metal roof profiles
• Commercial rainheads and overflow systems
• Restricted maintenance access
• Plant, equipment or rooftop services
• High wind exposure
• Warehouses containing stock or machinery

These conditions make coordination with the roof, hydraulic and maintenance documentation particularly important.

Internal and External Gutter Systems Are Different

An external eaves gutter beside a flat-pan roof generally requires DEKGUARD™.

An internal box gutter between a wall or upstand and an adjoining flat-based roof generally requires COMGUARD™.

The two systems should not be specified interchangeably.

COMGUARD™ for Internal Box Gutters

COMGUARD™ is designed to span internal box gutters commonly found on commercial, industrial and some residential buildings.

The system uses:

• Leaf Stopper Mesh Shield spanning the box-gutter opening
• Clampers at the wall, parapet or vertical upstand
• Gripits on the adjoining supported flat-based metal roof profile
• Suitable fasteners for the selected components and substrate

COMGUARD™ does not use:

• Trimets
• CORROGUARD® corrugated saddles
• DEKAFast saddles

Available COMGUARD™ Widths

COMGUARD™ is available in the following Mesh Shield widths:

• 250mm
• 500mm
• 750mm
• 1000mm

The selected width must span the required distance between the Clamper fixing point and the roof-side Gripit fixing point.

COMGUARD™ Is Not a Drainage Redesign

Before specifying COMGUARD™, confirm that the underlying box-gutter design and condition have been assessed separately.

The system cannot correct:

• Inadequate box-gutter capacity
• Insufficient fall
• Incorrect sump placement
• Undersized downpipes
• Blocked underground stormwater infrastructure
• Missing or inadequate overflow provisions
• Existing leaks or failed joints

Where the box gutter forms part of a complex or high-risk drainage system, the design should be reviewed by an appropriately qualified professional.

Measuring COMGUARD™ Width and Length

COMGUARD™ requires both a length measurement and a width selection.

Measure the Full Gutter Run

Record the total linear length of each separate box-gutter run, including:

• Changes in direction
• Internal corners
• Transitions between roof profiles
• Ends and termination points
• Sump and outlet locations
• Obstructions caused by plant or services

Measure the Required Mesh Span

Do not measure only the open channel or the bottom width of the box gutter.

The relevant measurement is the required span from:

• The proposed Clamper fixing point on the wall, parapet or vertical upstand
• Across the complete box-gutter opening
• To the appropriate Gripit fixing location on the adjoining supported roof pan

Select the COMGUARD™ width that provides the required coverage and installation allowance for that span.

Record Drainage Features

The roof plan or site measure should identify:

• Downpipe outlets
• Sumps
• Rainheads
• Overflow paths
• Scuppers
• Expansion joints
• Changes in gutter depth or width
• Areas requiring maintenance access

For a practical measurement workflow, see How to Measure for Gutter Guards: A Practical Guide for Australian Roofs.

DEKGUARD™ for External Flat-Pan Roofs

DEKGUARD™ is designed for external gutters beside supported flat-based metal roof profiles.

It uses:

• Mesh Shield spanning from the lower roof area to the external gutter edge
• Gripits secured to supported flat roof pans
• Trimets at a compatible traditional outer gutter edge
• Profile-specific quantities and positioning of Gripits

DEKGUARD™ Does Not Use Rib Saddles

Gripits are secured to supported flat pans. They should not be described as saddles and should not be specified as though they sit over high roof ribs.

The correct DEKGUARD™ product depends on:

• Roof manufacturer
• Exact roof profile
• Required Gripit quantity per metre
• External gutter configuration
• Mesh type and width

Refer to the DEKGUARD™ product information and confirm the exact manufacturer and roof profile before specifying the fixing arrangement.

DEKGUARD™ vs DEK-762™

DEKGUARD™ and DEK-762™ are separate systems despite their similar names.

DEKGUARD™

• Designed for supported flat-based roof profiles
• Uses Gripits on flat roof pans
• Selected according to manufacturer and profile
• Generally used beside compatible external eaves gutters

DEK-762™

• Designed for compatible DEK-762-style roof profiles
• Uses profile-specific DEKAFast saddles
• Secures the mesh at compatible roof ribs
• Does not use DEKGUARD™ Gripits

Specifying “DEKGUARD for Dek 762” is therefore technically incorrect.

Review the DEK-762 buying and fitting guide when the project uses a compatible DEK-762-style profile.

Compatible Commercial Roof Profiles

DEKGUARD™ and the roof side of COMGUARD™ support selected flat-based profiles from major Australian manufacturers.

Examples may include selected products from the following profile families.

Lysaght Profiles

• Klip-Lok 406
• Klip-Lok Classic 700
• Klip-Lok 700 Hi-Strength
• Trimdek®
• Spandek
• Flatdek
• Flatdek II
• Longline 305
• Integrity 820
• Spanrib
• Permalite V-Rib
• Permalite LT7
• Permalite Alspan

Metroll Profiles

• Metlok 700
• Metlock Cyclonic 680
• Hi-Deck 650
• Metrospan
• Spanplus 500
• Trimclad

Stramit Profiles

• Speed Deck 500
• Speed Deck Ultra
• CapacityPlus 660
• Megaclad
• Monoclad
• Longspan

This list does not mean that one Gripit arrangement fits every profile. The exact manufacturer and product name must be confirmed because pan geometry and fixing quantities differ.

Do Not Specify by Visual Similarity Alone

Where the roof profile is unknown, obtain:

• Original roofing documentation
• Manufacturer details
• Profile dimensions
• Clear photographs of the ribs and pans
• Confirmation from the roofing contractor or manufacturer

Commercial Mesh Specifications

Leaf Stopper provides three main Mesh Shield options.

Standard Mesh

• Aperture: 3.5mm × 3.5mm
• Aluminium thickness: 0.55mm
• Typical use: General leaves, twigs and larger debris
• Material: Non-combustible aluminium
• BAL status: Not the BAL-rated Leaf Stopper mesh option

Premium Mesh

• Aperture: 3.5mm × 3.5mm
• Aluminium thickness: 0.80mm
• Typical use: Applications where a thicker mesh is preferred
• Material: Non-combustible aluminium
• BAL status: Not the BAL-rated Leaf Stopper mesh option

Premium Mesh is approximately 46% thicker than Standard Mesh. It is not a finer-aperture product.

Fine Mesh

• Aperture: 1.8mm × 1.8mm woven mesh
• Aluminium thickness: 0.40mm
• Typical use: Pine needles, fine seeds and smaller leaf matter
• Material: Non-combustible aluminium
• BAL status: The BAL-rated option in the Leaf Stopper range

Mesh Selection Factors

The specification should consider:

• Surrounding vegetation
• Wind-blown litter
• Pine needles or narrow debris
• Dust and industrial particulates
• Required mesh strength
• Bushfire requirements
• Roof pitch
• Maintenance frequency
• Surface-debris management

Finer Mesh Does Not Exclude Everything

Dust, pollen and microscopic sediment may still pass through Fine Mesh or accumulate on its surface.

Fine Mesh can reduce smaller physical debris, but it does not remove the need for inspection or make the system immune to surface build-up.

Bushfire and BAL Specification

AS 3959:2018 addresses construction of buildings in bushfire-prone areas. The project team should confirm the applicable edition, amendments, National Construction Code provisions, state requirements and project approval conditions.

Specifications should avoid stating that any gutter guard product is universally “AS 3959 compliant” without identifying the exact clause, application and project requirements.

Non-Combustible vs BAL-Rated

All Leaf Stopper Mesh Shield options are made from non-combustible aluminium.

However:

• Standard Mesh is not the BAL-rated Leaf Stopper mesh option.
• Premium Mesh is not the BAL-rated Leaf Stopper mesh option.
• Fine Mesh is the BAL-rated option in the Leaf Stopper range.

The 2mm Aperture Requirement

Where mesh is being used as an ember guard or to protect relevant openings, a maximum aperture of 2mm is commonly specified.

Fine Mesh has a 1.8mm × 1.8mm woven aperture.

Government bushfire guidance also identifies non-combustible gutter and valley leaf guards as an important measure. These provisions should not be merged into a universal statement that every gutter guard on every BAL-rated building must perform the same function as an ember guard over an opening.

Relevant external references include:

• Standards Australia: AS 3959:2018
• CFA guide to retrofitting for bushfire protection
• Leaf Stopper bushfire protection information

Project-Specific Confirmation

For bushfire-prone commercial projects, confirm requirements with the appropriate:

• Architect
• Building certifier or surveyor
• Bushfire consultant
• Fire engineer
• Builder
• Relevant authority

Product selection alone does not establish whole-building compliance, certification, approval or insurance acceptance.

For further guidance, read the BAL 29 Gutter Guard Buying Guide.

Roof Drainage and Overflow Coordination

Gutter guard should be coordinated with the documented roof-drainage system.

The specification should require that Mesh Shield and associated components do not obstruct:

• Downpipe outlets
• Box-gutter sumps
• Rainheads
• Scuppers
• Overflow weirs
• Emergency overflow paths
• Expansion provisions
• Inspection openings

Do Not Specify Guaranteed Water Performance

Statements such as “will handle all high-volume water flow” or “prevents water overshooting” should not appear in the specification.

Water behaviour depends on:

• Catchment area
• Rainfall intensity
• Roof pitch
• Gutter dimensions
• Outlet and downpipe capacity
• Overflow design
• Mesh aperture
• Mesh position
• Surface contamination
• Maintenance condition

Inspect Existing Systems Before Retrofitting

For existing buildings, inspect and address:

• Standing water
• Incorrect gutter fall
• Corrosion
• Failed joints
• Blocked outlets
• Damaged sumps
• Inadequate overflow provisions
• Downstream stormwater restrictions

Gutter guard should not conceal an unresolved defect.

Fasteners, Coatings and Material Compatibility

Commercial specifications should identify the required system components rather than allowing arbitrary substitutions.

Component Selection

Depending on the system, components may include:

• Clampers
• Gripits
• Trimets
• DEKAFast saddles
• Corrugated saddles
• Colour-matched or otherwise suitable fasteners

Components from different Leaf Stopper systems should not be treated as interchangeable.

Fastener Suitability

Fastener selection should consider:

• Roof-sheet material
• Roof coating
• Substrate thickness
• Environmental exposure
• Wind conditions
• Manufacturer requirements
• Installation instructions

Coastal and Industrial Exposure

Powder-coated aluminium is generally well suited to external gutter-guard applications, but no exposed metal system should be described as immune to corrosion or environmental degradation.

Salt spray, industrial pollutants, damaged coatings, incompatible metals and poor maintenance can all affect system condition.

For more on finishes, read The Homeowner’s Guide to Powder Coated Gutter Guards in Australia.

Specifying Maintenance Access

Commercial gutter guard specifications should include an access strategy rather than assuming the mesh will never need to be opened.

Inspection may still be required for:

• Fine sediment
• Storm debris
• Surface contamination
• Downpipe entrances
• Sumps
• Rainheads
• Overflow provisions
• Loose or damaged components

Access-Panel Locations

Potential access locations include:

• Near critical downpipe outlets
• Adjacent to box-gutter sumps
• At ends of long gutter runs
• Near changes in direction
• In high-debris areas
• Where safe future access would otherwise require removing long mesh sections

Do not apply a universal rule requiring an access panel at every downpipe or at fixed intervals. Access spacing should be based on the specific system layout and maintenance plan.

EasyAc® and EasyAc20®

The EasyAc® product range provides removable access through Leaf Stopper Mesh Shield, allowing a gutter or downpipe opening to be inspected without removing a long section of gutter guard.

The original Steel EasyAc® was introduced in 2010. EasyAc20® was released in 2025 as a longer aluminium access panel available in a range of colours.

Additional EasyAc® product information is available from easyac.com.au.

Steel EasyAc®

• The original EasyAc® model introduced in 2010
• Manufactured from steel
• Uses a louvered lid
• The lid slides onto the base plate from one end
• Provides local access for gutter and downpipe inspection or cleaning

EasyAc20®

• Released in 2025
• Longer than the original Steel EasyAc®
• Manufactured from aluminium
• Available in a range of colours
• The lid is positioned beside the slotted tabs and pushed sideways into place
• Provides a larger local access area for inspection and maintenance

Patented Screw-Free Base Plate

Both EasyAc® systems use patented internal tabs that are pushed underneath the gutter guard mesh to keep the base plate in place.

The system does not use screws to secure the removable lid. This means a screwdriver is not required each time the lid needs to be removed or replaced for inspection or cleaning.

A gutter or downpipe may not require attention for several years, but installing an access panel during the original gutter guard installation means the access point is already available when maintenance is eventually needed.

Where EasyAc® May Be Useful

EasyAc® or EasyAc20® may be considered near:

• Downpipe outlets
• Box-gutter sumps
• Ends of long gutter runs
• Changes in gutter direction
• Areas exposed to concentrated debris
• Locations where removing a long mesh section would otherwise be required

The number and placement of access panels should reflect the gutter layout, drainage features and planned maintenance strategy rather than a universal spacing rule.

EasyAc® Limitations

EasyAc® and EasyAc20®:

• Provide local inspection and cleaning access.
• Do not replace the main gutter guard system.
• Do not automatically clear a blockage.
• Cannot clear a restriction further down a downpipe.
• Cannot clear underground stormwater infrastructure.
• Are not automatically included in standard Leaf Stopper gutter guard kits.

Commercial Installation and Handover

Commercial installations should be completed in accordance with the selected system instructions, site safety requirements and project documentation.

Pre-Installation Requirements

Before work begins:

• Confirm the roof and gutter profiles.
• Confirm the specified Mesh Shield type.
• Clean the gutter and drainage outlets.
• Repair identified defects.
• Confirm access-panel locations.
• Confirm that overflows and sumps will remain unobstructed.
• Confirm safe roof-access arrangements.
• Coordinate with rooftop services and other trades.

Installation Inspection

The completed work should be checked for:

• Correct system components
• Correct Mesh Shield width
• Appropriate Gripit or Clamper positioning
• Secure components without excessive distortion
• Supported mesh spans
• Finished joins and terminations
• Accessible outlets and sumps
• Unobstructed overflow provisions
• Installed access panels
• Damage to coatings or roof sheets

Handover Information

The building owner or facility manager should receive:

• Product identification
• Mesh type and aperture
• Roof-profile information
• Installation instructions
• Access-panel locations
• Inspection recommendations
• Warranty information where applicable
• Photographs of concealed or difficult-to-view areas

Sample Commercial Gutter Guard Specification

The following is a project-planning example only. It should be adapted by the project team to the actual roof, gutter, drainage and approval requirements.

Commercial Specification Checklist

• Has the gutter been identified as external or internal?
• Has the exact roof manufacturer and profile been confirmed?
• Has the correct Leaf Stopper system been selected?
• Has the total gutter length been measured?
• Has the required Mesh Shield width been measured?
• Have downpipes, sumps, rainheads and overflows been recorded?
• Has the hydraulic and drainage design been reviewed separately?
• Has Standard, Premium or Fine Mesh been selected?
• Have bushfire requirements been confirmed?
• Have the correct Clampers, Gripits, Trimets or saddles been identified?
• Have EasyAc® or EasyAc20® access locations been documented?
• Have coating and material-compatibility requirements been considered?
• Have existing roof and gutter defects been addressed?
• Have installation and height-safety responsibilities been assigned?
• Have inspection and handover requirements been documented?

Specify the Complete Commercial System

Effective commercial gutter guard specifications should define the complete profile-specific system rather than relying on a generic mesh note.

For internal box gutters, COMGUARD™ uses Clampers and Gripits and is available in 250mm, 500mm, 750mm and 1000mm Mesh Shield widths.

For external gutters beside supported flat-based metal roofs, DEKGUARD™ uses profile-specific Gripits. For compatible DEK-762-style roofs, DEK-762™ uses DEKAFast saddles.

The final specification should also coordinate mesh selection, drainage features, EasyAc® access panels, bushfire requirements, installation and future maintenance.

Review the Industrial Gutter Guard Solutions Buying Guide, explore the COMGUARD™ range or contact Leaf Stopper to discuss a commercial project.

Frequently Asked Questions

What information should commercial gutter guard specifications include?

The specification should identify the gutter type, roof manufacturer and profile, complete Leaf Stopper system, mesh aperture and thickness, system width, fixing components, access locations, drainage features, finish and installation requirements.

Which Leaf Stopper system suits internal box gutters?

COMGUARD™ is designed for internal box gutters.

What components does COMGUARD™ use?

COMGUARD™ uses Clampers at the wall or vertical upstand and Gripits on the adjoining supported flat-based roof profile.

Does COMGUARD™ use Trimets?

No. COMGUARD™ does not use Trimets.

What COMGUARD™ widths are available?

COMGUARD™ is available in 250mm, 500mm, 750mm and 1000mm Mesh Shield widths.

How should COMGUARD™ width be measured?

Measure the required span from the wall or vertical-upstand Clamper fixing point to the roof-side Gripit fixing point. Do not measure only the bottom of the box-gutter channel.

What is the difference between COMGUARD™ and DEKGUARD™?

COMGUARD™ spans internal box gutters using Clampers and Gripits. DEKGUARD™ is generally used with external gutters beside supported flat-based roof profiles and uses Gripits and compatible external gutter-edge components.

What is the difference between DEKGUARD™ and DEK-762™?

DEKGUARD™ uses Gripits on supported flat roof pans. DEK-762™ uses profile-specific DEKAFast saddles on compatible roof ribs.

Can DEKGUARD™ be specified for a DEK-762 roof?

Not automatically. DEK-762™ is a separate Leaf Stopper system. Confirm the actual roof profile before specifying either product.

Which commercial mesh is BAL-rated?

Fine Mesh is the BAL-rated mesh option in the Leaf Stopper range. Standard and Premium Mesh are non-combustible aluminium but are not the BAL-rated options.

Does Fine Mesh guarantee AS 3959 compliance?

No. Mesh selection is only one part of the building and approval requirements. Compliance depends on the application, BAL assessment, installation and complete project documentation.

Is a 2mm aperture required for every commercial gutter guard?

No universal statement should be made. A maximum 2mm aperture is commonly required where mesh serves as an ember guard or protects relevant openings. Gutter and valley leaf-guard requirements must be assessed in the applicable project context.

Can gutter guard prevent a commercial box gutter from overflowing?

No system can guarantee this. Overflow risk depends on catchment, rainfall, gutter dimensions, outlets, downpipes, overflows, surface condition and maintenance.

Can gutter guard correct an undersized drainage system?

No. It cannot increase gutter capacity or correct undersized downpipes, inadequate falls or blocked stormwater infrastructure.

What is the difference between Steel EasyAc® and EasyAc20®?

Steel EasyAc® is the original model introduced in 2010. It has a louvered steel lid that slides onto the base plate from one end. EasyAc20® was released in 2025, is longer, is manufactured from aluminium and is available in a range of colours. Its lid is positioned beside the slotted tabs and pushed sideways into place.

Is EasyAc20® made from aluminium?

Yes. EasyAc20® is a longer aluminium access panel released in 2025 and available in a range of colours.

Do EasyAc® access panels require screws?

No. Both Steel EasyAc® and EasyAc20® use patented internal tabs pushed beneath the gutter guard mesh to secure the base plate. A screwdriver is not required each time the removable lid is taken off or replaced.

Should EasyAc20® be installed at fixed intervals?

Not as a universal rule. Access spacing should be based on the gutter layout, outlets, sumps, debris conditions and maintenance strategy.

Are commercial gutter guards maintenance-free?

No. They help reduce larger debris entering the gutter, but periodic inspection may still be required for sediment, surface debris, drainage outlets and system condition.