K4 Roof Treatment
Why spend thousands on having your roof cleaned when we can do it for less than 60% of what you’ve been quoted?
12-month warranty on effectiveness — works every time, stays cleaner longer, and has been around for over 40 years!
*We can even quote over the phone!
Safe Formula, Long-Lasting, Biodegradable, Guaranteed Results
Professional Service
100% Safe Formula
Massive Savings
Roof Protection
Fast Results
12-Month Guarantee
Service Areas
We services Greater Sydney Including:
Real Results From Real Homeowners
Michael Thompson Parramatta NSW
Rebecca Collins Castle Hill NSW
John Matthews Blacktown NSW
Get Your Free Quote or Buy K4 Product in 60 Seconds
Service & Product Pricing
K4 Product
DIY — Same Formula
$199
/ One-Time
Do it yourself with the same proven formula used by the pros.
- Cost-effective
- Same K4 formula
- DIY at your pace
K4 Service
Guaranteed Results
$750
/ One-Time
Full service done by our pro crew with guaranteed quality.
- Experienced team
- No hassle
- Guaranteed outcome
About Us
At Clean Gutter Clean, we specialise in safe and effective exterior cleaning using our proven soft-wash K4 treatment. Instead of harsh pressure washing, our biodegradable solution penetrates deep to kill moss, algae, lichen, mould, and other growths at the root without damaging surfaces.
Our focus is on long-lasting results, eco-friendly practices, and protecting your home from costly deterioration. Whether it’s roofs, driveways, paths, decks, or exterior walls, K4 treatment cleans naturally over time through rain and weather without scrubbing or blasting.
We are committed to delivering reliable service, affordable pricing, and visible results that keep your property cleaner, safer, and looking its best.
The Benefits of Choosing K4 Over Pressure Washing
Pressure Washing
$1,500–$2,500
- Contractors often break or disturb tiles
- Damage to the veneer of the tile with high pressure
- Pointing/Mortar is disturbed or blown away
- Water entering the roof space = ceiling stains
- Only surface spores are removed so lichen grows back again in a much shorter time frame
- A lot of debris is spread everywhere requiring extra clean up
- Cost is always higher with high pressure cleaning
- Can remove paint and colour from tiles.
K4 Treatment
$750
- Easy spray-on application – no scrubbing or pressure washing needed
- Biodegradable biocide formula that is safe and eco-friendly
- No contractors walking all over your roof – greatly reduces risk of tile or coating damage
- Penetrates deep into cracks and joints to kill moss, algae, lichen, and mould at the root
- Natural weathering from rain gradually washes away dead growth
- Provides long-lasting protection and cleaner surfaces for 3–5 years
- Includes a 12-month treatment warrant
- Safe to use around pets and plants when applied as directed
- Eliminates spores that pressure washing often leaves behind, preventing fast regrowth
- No risk of veneer damage, water intrusion or mortar disturbance
- Ideal for older, fragile or heavily infected roofs
How Our Treatment Works
Spray Application
K4 is diluted with water and sprayed directly onto the affected surfaces. Only one saturation coat is needed.
Deep Penetration
For best results:
- Moss should be allowed to dry before application
- K4 must saturate the growth to the base
- After application, we allow the treated areas to dry 3–4 hours (longer in cold conditions)
This ensures the solution penetrates deeply and concentrates inside the growth.
Natural Cleaning
Once treated, the growth begins to die immediately.
Wind and rain naturally wash away dead moss, algae, and lichen over time:
- Concrete surfaces: 2–4 months
- Other surfaces: 3–12 months, depending on weather, material, and growth level.
For faster results, the area can be brushed or rinsed 3–4 weeks after treatment.
Long-Term Protection
K4 offers surface protection for up to 12 months, and in shaded or damp environments, reapplication is recommended when regrowth first appears.
Why Our Method Is Better Than Others
No Pressure Washing Required
Pressure cleaning removes visible moss, but:
- It doesn’t kill the roots
- Moss quickly returns
- It can damage surface coatings
K4 eliminates growth at the source, preventing regrowth naturally.
Biodegradable and Safe
When applied correctly:
- K4 does not kill plants
- Pets are safe once kept away during treatment
- Surfaces remain unharmed
- No toxic damage to roof coatings, stone-chip surfaces, or concrete tiles
It is safe for use around people, pets, gardens, and landscaping.
Prevents Accidents
Our treatments reduce slip hazards on:
- Walkways
- Driveways
- Patios
- Decks
This helps prevent falls and injuries caused by algae-covered surfaces.
Protects Your Property
Moss and algae can:
- Eat away mortar joints
- Damage Colourbond and Decrabond coatings
- Shorten roof lifespan
K4 protects your surfaces and helps maintain long-term structural integrity.
Cost-Effective and Low Maintenance
- One treatment lasts up to 12 months
- No expensive machinery
- No repeat manual cleaning
- Surfaces stay cleaner for longer
Hear From Our Clients
Frequently Asked Questions
Yes, our formula is biodegradable with no acids or bleaches. Safe for family, pets, and plants.
We complete most roofs in 2–3 hours. Results start showing in 2–4 weeks.
A short consultation is needed. You don’t need to be present the entire time.
K4 is a biodegradable biocide that kills moss, algae, lichen, mould and other growths on exterior surfaces without scrubbing or high-pressure washing.
– K4 is applied as a spray that penetrates deep into the growth.
– Over time, rain and wind naturally remove the dead moss and algae without damaging the surface.
– Concrete surfaces may take 2–4 months to clean.
– Other surfaces may take 3–12 months, depending on severity, surface type and weather conditions.
No. K4 does not require pressure washing or scrubbing, meaning there is no risk of tile, veneer, mortar or coating damage.
– Pressure washing only removes surface growth and often leaves spores behind.
– This means moss and algae can grow back much faster.
– K4 kills growth at the root for a longer-lasting clean.
– Yes, but pets should be kept indoors during treatment to avoid contact.
– If your property is connected to tanks, disconnect them from guttering for at least 10 days.
K4 prevents regrowth for up to 12 months, and roofs often stay clean for 3–5 years, depending on conditions.
No. K4 is a spray-on treatment that works on its own. Weather removes the dead growth naturally.
K4 is suitable for most exterior surfaces, including:
– Roofs
– Concrete
– Asphalt
– Sandstone
– Bricks
– Synthetic turf
– Timber decks
– Patios, paths and driveways
ichael Thompson, Parramatta NSW
Our roof had become dull and covered with years of mould and debris. The Clean Gutter Clean team used their soft-wash system and the results were unbelievable. The tiles look cleaner, brighter, and refreshed without any damage. The team was polite, careful around the house, and cleaned everything up afterwards. Truly a five-star experience.