How to Choose COMGUARD™ for an Internal Box Gutter: Width, Roof Profile & Access

Choosing gutter guard for an internal box gutter requires more information than simply measuring the gutter length.

You also need to know the width of the area being protected, the adjoining roof manufacturer and profile, the type of debris around the building, and how the gutter will be inspected after the Mesh Shield is installed.

Leaf Stopper COMGUARD™ is designed specifically for compatible internal box gutters. Unlike a conventional external gutter installation, it spans between a wall or vertical upstand and a supported flat-based metal roof profile.

This guide explains how to identify the right COMGUARD™ configuration before ordering.

What Is COMGUARD™?

COMGUARD™ is Leaf Stopper's gutter guard system designed for compatible internal box gutters.

Internal box gutters are commonly found:

• Between roof spans
• Behind parapet walls
• Along commercial and industrial roofs
• Inside the overall building footprint
• On some residential architectural roof designs

Unlike a traditional external eaves gutter, a box gutter often has a wall or vertical upstand on one side and a metal roof profile on the other.

COMGUARD™ is configured to span across this opening.

Is COMGUARD™ the Right Leaf Stopper System?

Start by identifying the gutter configuration.

Choose COMGUARD™ When:

• You have an internal box gutter
• There is a suitable wall, parapet or vertical upstand on one side
• The opposite side adjoins a supported flat-based metal roof profile
• You want to reduce leaves and larger debris entering the internal gutter

Do Not Automatically Choose COMGUARD™ For:

• Standard external fascia gutters
• Traditional curved corrugated roof edges
• Concrete or terracotta tiled roof edges
• External flat-pan gutter-edge applications

Leaf Stopper has different systems for these configurations.

• CORROGUARD® — compatible traditional curved corrugated roofs
• TILEGUARD™ — compatible concrete and terracotta tiled roofs
• DEK-762™ — compatible DEK-762-style roof geometry
• DEKGUARD® — supported flat-based metal profiles with conventional external gutters

COMGUARD™ is specifically the internal box-gutter solution.

What Should You Measure Before Ordering COMGUARD™?

Do not order solely from the total lineal metres of gutter.

For a more accurate configuration, collect the following information.

1. Total Box Gutter Length

Measure each box-gutter run you intend to protect.

Record separate runs individually rather than combining everything into a single number immediately. This makes it easier to identify changes in gutter width, roof profile or gutter configuration.

2. Required Mesh Span

Measure the area that Mesh Shield needs to cover between the vertical fixing surface and the adjoining roof-side fixing location.

This determines which Mesh Shield width is appropriate.

3. Roof Manufacturer

Identify the manufacturer of the adjoining roof sheet where possible.

4. Exact Roof Profile

Record the actual profile name.

Do not rely on descriptions such as:

• Metal roof
• Flat roof
• Deck roof
• COLORBOND® roof

These descriptions are not specific enough to determine the required roof-side fixing configuration.

5. Important Drainage Features

Identify:

• Downpipe outlets
• Sumps
• Rainheads
• Overflow provisions
• Changes in gutter width
• Unusual flashing or roof junctions

These should be considered before deciding how the Mesh Shield and future access points will be configured.

Which COMGUARD™ Mesh Shield Width Do You Need?

Current COMGUARD™ configurations offer four Mesh Shield widths:

• 250mm
• 500mm
• 750mm
• 1000mm

The correct width depends on the actual span that needs to be covered.

Do not automatically select a 1000mm Mesh Shield because the property is commercial or because the box gutter itself appears large.

The goal is to select the appropriate Mesh Shield for the particular configuration.

Do Wide Box Gutters Need Overlapping Mesh?

Do not use a generic overlap rule such as "20–30mm for thermal movement" unless it appears in the current Leaf Stopper installation instructions for the particular detail.

COMGUARD™ offers several Mesh Shield widths specifically to accommodate different box-gutter spans.

Any joins, overlaps and fixing details should follow the current installation requirements rather than an invented universal dimension.

Why the Roof Profile Matters

One side of COMGUARD™ attaches to a vertical surface.

The other side attaches to the adjoining flat-based metal roof.

This is where profile identification becomes important.

Flat-based metal roofing varies between manufacturers in characteristics such as:

• Rib shape
• Rib height
• Pan width
• Cover width
• Pan geometry

COMGUARD™ therefore uses the selected roof profile to determine the appropriate Gripit configuration.

Do Not Treat COLORBOND® as a Roof Profile

COLORBOND® is a branded steel product used to manufacture many roof profiles.

Saying a warehouse has a "COLORBOND® roof" is not enough to select the correct COMGUARD™ configuration.

You still need to identify the actual roof profile.

How Is COMGUARD™ Secured?

COMGUARD™ uses a different fixing arrangement from conventional Leaf Stopper gutter-edge installations.

Wall Side: Clamper Strips

Clampers secure one side of Mesh Shield against the appropriate wall, parapet or vertical upstand.

Roof Side: Gripit Brackets

Leaf Stopper's patented Gripit brackets secure the other side of Mesh Shield to the supported flat base of the adjoining metal roof profile.

The current COMGUARD™ order system calculates the number of Gripits required according to the roof profile selected.

Colour-Matched Screws

COMGUARD™ kits also include screws selected to match the Clampers and Gripits.

Does COMGUARD™ Use Saddles?

No.

Do not confuse COMGUARD™ with systems such as CORROGUARD® or DEK-762™ that use profile-specific saddle components.

COMGUARD™ uses Clampers and Gripits.

Does COMGUARD™ Use Trimets?

The standard internal box-gutter COMGUARD™ configuration does not use the Trimet arrangement used along compatible conventional external gutter edges.

This is another important difference between COMGUARD™ and DEKGUARD®.

COMGUARD™ vs DEKGUARD®

These systems can be confused because both may use Gripit technology.

If the gutter is external rather than an internal box gutter, start with the DEKGUARD® information instead.

Choosing Standard, Premium or Fine Mesh

After selecting the COMGUARD™ configuration, choose the appropriate Mesh Shield.

Standard Mesh

• Aperture: 3.5mm × 3.5mm
• Thickness: 0.55mm aluminium
• Material: Non-combustible aluminium
• Best suited to: General leaves, twigs and larger debris

Premium Mesh

• Aperture: 3.5mm × 3.5mm
• Thickness: 0.80mm aluminium
• Difference: Approximately 46% thicker than Standard Mesh
• Material: Non-combustible aluminium

Premium Mesh is thicker than Standard Mesh but uses the same aperture.

It is not a finer mesh.

Fine Mesh

• Aperture: 1.8mm × 1.8mm woven mesh
• Thickness: 0.40mm aluminium
• Best suited to: Pine needles, fine seeds and smaller debris
• Bushfire applications: Leaf Stopper's BAL-rated Mesh Shield option where applicable

Does a Commercial Building Automatically Need Premium Mesh?

No.

The fact that a building is commercial or industrial does not automatically determine its Mesh Shield.

Consider:

• Surrounding vegetation
• Debris type
• Desired mesh strength
• Fine-debris requirements
• Bushfire requirements where applicable
• Project specification

Will COMGUARD™ Affect Box Gutter Drainage?

COMGUARD™ is intended to help reduce larger debris entering the gutter.

It should not be described as determining or guaranteeing the hydraulic performance of the box gutter.

The drainage system itself still needs to account for factors such as:

• Roof catchment
• Design rainfall
• Box-gutter dimensions
• Gutter fall
• Sumps
• Rainheads
• Outlet capacity
• Downpipe capacity
• Overflow provisions
• Downstream stormwater

Mesh should also not obstruct components intentionally incorporated into the drainage design.

Does COMGUARD™ Make a Box Gutter AS/NZS 3500.3 Compliant?

No product should be presented that way.

AS/NZS 3500.3 relates to stormwater drainage design and installation.

Compliance depends on the complete drainage system and project—not simply whether gutter guard has been installed.

Where hydraulic design or regulatory compliance is relevant, the appropriate designer, plumber, builder or certifier should determine the requirements.

For more detailed project-level considerations, read the Commercial Gutter Guard Specifications Guide.

Can COMGUARD™ Prevent Box Gutter Overflow?

No gutter guard can guarantee that an internal box gutter will never overflow.

COMGUARD™ can help reduce one potential source of restriction by reducing larger debris entering the gutter.

Overflow may still result from:

• An undersized gutter
• Insufficient outlet capacity
• Blocked downpipes
• Blocked downstream stormwater
• Incorrect gutter fall
• Obstructed overflow provisions
• Exceptional rainfall
• Fine sediment accumulation
• Other drainage faults

If a box gutter already overflows, investigate the drainage problem before assuming gutter guard will solve it.

Planning Future Access with EasyAc®

A box gutter with Mesh Shield still needs to remain inspectable.

Fine dust and sediment can pass through the mesh, and important components such as outlets may need future inspection.

EasyAc® is an optional local access product that can be considered as part of the maintenance plan.

Depending on the installation, an access point may be useful near:

• Selected downpipe locations
• Gutter low points
• Long gutter runs
• Sediment-prone areas
• Other locations where future inspection is anticipated

There is no universal requirement for one EasyAc® at every downpipe or a fixed spacing between access panels.

Plan access according to the specific gutter layout.

COMGUARD™ and Bushfire Requirements

All three Leaf Stopper Mesh Shield grades are manufactured from aluminium and are non-combustible.

Fine Mesh is the BAL-rated Mesh Shield option within the range where applicable.

That does not mean every commercial building in a bushfire-prone area requires Fine Mesh.

Nor does installing Fine Mesh make the complete commercial property BAL compliant.

If COMGUARD™ forms part of a specific bushfire construction requirement, confirm the applicable mesh material, aperture and installation configuration.

See the Leaf Stopper Bushfire Protection page for further information.

Do You Still Need to Maintain a Protected Box Gutter?

Yes.

COMGUARD™ reduces larger debris entering the channel but does not eliminate maintenance.

Periodic inspection should consider:

• Mesh surface debris
• Fine sediment inside the gutter
• Sumps
• Rainheads
• Outlets
• Overflow provisions
• Downpipe entrances
• Physical damage to Mesh Shield
• Loose or disturbed components

Inspection frequency should reflect the site rather than an arbitrary annual or six-month schedule.

For a practical maintenance checklist, read Preventing Blocked Box Gutters: The Essential Maintenance Checklist.

COMGUARD™ Ordering Checklist

Before configuring a COMGUARD™ system, gather:

• □ Total length of each internal box-gutter run
• □ Required Mesh Shield span
• □ Roof manufacturer
• □ Exact adjoining roof-profile name
• □ Clear photographs of the gutter and roof junction
• □ Locations of outlets and downpipes
• □ Locations of sumps or rainheads
• □ Locations of overflow provisions
• □ Selected Standard, Premium or Fine Mesh
• □ Preferred colour
• □ Any planned EasyAc® access locations
• □ Any project-specific bushfire requirements

If you are still comparing different box-gutter protection approaches, first read Best Box Gutter Leaf Guard Systems for Australian Properties.

For detailed commercial project requirements, continue to the Commercial Gutter Guard Specifications Guide.

When you're ready to choose your system, visit the COMGUARD™ product information page or shop Leaf Stopper gutter guard systems.

For larger, high or complex installations, you can also find a Leaf Stopper installer.

Frequently Asked Questions

What is COMGUARD™?

COMGUARD™ is Leaf Stopper's gutter guard system for compatible internal box gutters. It uses Clampers at the wall or vertical upstand and Gripits on the supported adjoining flat-based metal roof.

What widths does COMGUARD™ come in?

Current COMGUARD™ configurations offer 250mm, 500mm, 750mm and 1000mm Mesh Shield widths.

Does COMGUARD™ use Gripits?

Yes. Patented Gripits secure Mesh Shield to the supported flat-based adjoining roof profile.

Does COMGUARD™ use saddles?

No. COMGUARD™ uses Clampers and Gripits. Do not confuse it with Leaf Stopper systems that use profile-specific saddles.

Does COMGUARD™ use Trimets?

Not in the standard internal box-gutter configuration. Clampers are used on the wall or vertical-upstand side instead.

How do I know which Gripits I need?

Identify the manufacturer and exact adjoining roof profile. The current COMGUARD™ ordering system uses the roof-profile selection to calculate the required Gripit quantity.

Which COMGUARD™ mesh is best?

It depends on the project. Standard Mesh suits general larger debris, Premium provides a thicker 0.80mm mesh with the same 3.5mm aperture, while Fine Mesh uses a 1.8mm × 1.8mm aperture for finer debris and applicable BAL-rated applications.

Will COMGUARD™ stop my box gutter overflowing?

No. It can help reduce larger debris entering the gutter, but overflow also depends on the complete hydraulic and stormwater system.

Does COMGUARD™ meet AS/NZS 3500.3?

COMGUARD™ should not be described as independently making a drainage system compliant with AS/NZS 3500.3. Compliance depends on the complete project and drainage design.

Can EasyAc® be used with COMGUARD™?

EasyAc® may provide useful local inspection access in an appropriate configuration. It is optional rather than automatically included with the COMGUARD™ kit.