Article type: Installation guidance
Audience: Australian homeowners, builders and installers planning a roof cable entry for Starlink or similar communications equipment
Primary use case: A cable passing from a roof-mounted antenna/dish into the roof space on an existing or new home
Short answer
For most Starlink and communications installs, the cable entry will be added to an existing roof. The best approach is still to create a proper flashed roof penetration rather than drilling a hole and filling it with silicone. Use a short, UV-stable conduit or sleeve through the roof, then seal the roof penetration with a correctly sized Dektite flashing around that sleeve, not around a loose cable. The Dektite should be installed by a roofer, builder or suitably qualified installer, and communications/data cabling should be handled by a registered cabler where required.[9][10]
A Dektite is not just a blob of silicone. The manufacturer’s metal-roof installation sequence is to trim the boot to suit the pipe size, make sure the surface is clean and dry, slide the boot down, apply sealant under the flexible flange, press the base firmly into the roof profile, smooth creases, and fasten it with self-sealing screws.[2]
Why this matters
Every roof cable entry is also a water-entry risk. Australian metal roof manufacturers treat penetrations as part of the roof drainage system because penetrations can block or redirect water running down roof pans.[9]
On an existing home, the installer also has to work around the roof profile, existing penetrations, solar panels, ceiling access, insulation, and the final location of the modem/router or internal network point. The goal is to create a serviceable, weatherproof cable entry without compromising the roof sheet or relying on sealant as the only waterproofing layer.
A small penetration can be flashed with a flanged sleeve, but the flashing must not dam valleys or pans; if the penetration blocks drainage, moisture can sit on the sheet and reduce coating life or appearance.[9]
For Starlink-style installs, the common mistake is trying to seal directly around the cable. A better long-term detail is to pass the cable through a short conduit or sleeve, then use the Dektite to seal around the round sleeve. This avoids relying on silicone around a flexible cable and gives the roofer a proper circular surface to flash.
Recommended detail for existing homes
Use this approach when adding Starlink, an antenna, CCTV, a data cable or another communications cable to a roof that is already installed.
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Inspect the roof before drilling.
Check the roof profile, roof pitch, sheet condition, access from inside the roof space, nearby solar panels, existing penetrations, gutters, valleys and likely water flow. Do not choose a location just because it is directly under the device; choose a location that can be flashed properly and reached safely. -
Choose a location that keeps water moving.
Put the penetration where the Dektite base can sit cleanly on the roof sheet without blocking a pan, valley, side lap or gutter flow. LYSAGHT specifically warns not to dam valleys or pans because rainwater needs to drain freely from the high side of the penetration.[9] -
Use a sleeve or conduit, not a bare cable hole.
A short UV-stable conduit or flanged sleeve gives the flashing a stable round surface. LYSAGHT describes a flanged cylindrical sleeve as a simple flashing method for small penetrations such as pipes where the penetration fits between ribs or only penetrates one rib.[9] -
Use a retrofit/split Dektite if the cable or connector is already in place.
Many communications cables are pre-terminated and should not be cut just to pass through a flashing. If the connector cannot pass through a standard closed boot, use a split/retrofit style flashing or size the sleeve so the connector can pass through before the final weatherproofing is completed. DEKS lists Dektite Retrofit and Dektite Combo products, and the Combo installation guide describes wrapping the boot around the pipe with the seam in the downstream position, clipping it closed, sealing the seam and underside, then fastening the base.[1][2] -
Size the Dektite to the sleeve.
Select a Dektite size where the boot can be trimmed to grip the conduit or sleeve firmly. DEKS lists Dektite products in multiple size ranges, including micro, premium, combo and retrofit options, so the installer should match the flashing to the outside diameter of the sleeve rather than forcing an oversized boot to work.[1] -
Install the flashing to the manufacturer’s sequence.
For Dektite Premium on metal roofs, DEKS says to trim the boot to suit the pipe size, ensure the surface is clean and dry, slide the flashing down the pipe, apply sealant under the flexible flange, press the base firmly to the roof profile, smooth out creases, and fasten with self-sealing screws.[2] -
Use the correct sealant.
For coated steel roofing, use neutral-cure silicone. LYSAGHT says neutral-cure silicone sealants are water resistant, non-corrosive, flexible across temperature extremes and suitable for steel roofing and walling; it also warns that other silicones can release aggressive by-products that are detrimental to sheet steel.[9] -
Protect the cable inside and outside.
Leave a neat drip loop outside the entry, protect the cable from sharp metal edges, and secure it so it cannot rub in wind. Inside the roof space, route it away from heat sources, sharp framing edges and areas likely to be stepped on during future maintenance. -
Seal the sleeve/cable transition separately.
The Dektite seals the roof to the sleeve. The cable still needs a weather-resistant transition at the top or underside of the sleeve, such as an approved gland, cap, bend or internal drip arrangement suitable for the cable type. Do not fill the conduit with hard-setting sealant that may damage the cable or prevent replacement. -
Check compliance and trade responsibility.
Roof cutting and flashing should be done by the roofing trade or builder, especially where workmanship, safety and roof warranty matter. ACMA says registered cablers can install communications cabling in new houses and offices, and can install data cabling for computers that connect to the telecommunications network.[10]
Additional note for new builds
If the home is still being built, plan the roof penetration before the roof and internal linings are finished. This gives the builder, roofer and cabler a chance to choose a better cable route, avoid structural members, avoid future access problems, and finish the penetration before insulation and plasterboard make the job harder.
What not to do
- Do not drill a hole and rely on silicone alone.
- Do not flash directly to a loose cable if a sleeve or conduit can be used.
- Do not place the penetration where it blocks a roof pan, valley, side lap or gutter flow.[9]
- Do not use acetic-cure or unknown silicone on COLORBOND®/ZINCALUME® style steel roofing; use a compatible neutral-cure product.[9]
- Do not leave swarf, sharp sheet-metal edges, or unsupported cut ribs around the penetration. LYSAGHT notes that where roof cladding is cut, extra support may be required, and if sheet ribs are cut, framing must support the cut ends each side of the penetration.[9]
- Do not let the cable become the mechanical support for the roof-mounted equipment.
- Do not bury a proprietary connector in sealant where it cannot be inspected or replaced.
Installer checklist
Before drilling or cutting the roof:
- Confirm the roof material, profile, pitch and condition.
- Confirm safe roof access and internal ceiling-space access.
- Confirm the cable route from the roof equipment to the internal equipment location.
- Confirm whether the cable connector can pass through the planned sleeve.
- Confirm whether a standard or retrofit/split Dektite is required.
- Confirm the conduit/sleeve outside diameter and Dektite size.
- Confirm the penetration does not dam roof pans or valleys.[9]
- Confirm the roof surface is clean and dry before sealant is applied.[2]
- Confirm neutral-cure silicone and self-sealing screws are used.[2][9]
- Confirm the Dektite base is dressed into the roof profile without creases.[2]
- Confirm the cable is protected from abrasion at both ends of the sleeve.
- Confirm the cabling work is handled by the correct trade or registered cabler where required.[10]
Plain-English recommendation
For an existing home, ask the installer for a “flashed conduit roof penetration for a communications cable” rather than “a hole for the Starlink cable”. The professional detail is: inspect the roof first, choose a location that keeps water moving, pass the cable through a conduit/sleeve, flash the sleeve with a correctly sized Dektite, use neutral-cure silicone under the flange, fasten with self-sealing screws, protect the cable from abrasion, and avoid blocking roof pans.[2][9]
Sources
[1] https://deks.com.au/product-category/dektite-rubber — deks_product
[2] https://3986358.app.netsuite.com/core/media/media.nl?id=4739184&c=3986358&h=b2fe041394ff1e279f9a&_xt=.pdf — netsuite_pdf
[9] https://cdn.dcs.bluescope.com.au/download/lysaght-roofing-walling-installation-manual — LYSAGHT roofing and walling installation manual
[10] https://www.acma.gov.au/cabling-your-home-or-office — ACMA cabling your home or office