Moss & Mould Killer - 50% Benzalkonium Chloride: How to Remove Moss and Mould from Your Driveway or Roof
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Green, slippery patches on your driveway or black streaks on your roof? That's moss, algae, or lichen and it's one of the most common outdoor cleaning problems for Kiwi homes and businesses. The good news: it's easy to treat with the right product and the right tool.
The Fix: Moss & Mould Killer (50% Benzalkonium Chloride) Highly Concentrated
Our Moss & Mould Killer is a 50% Benzalkonium Chloride-based treatment that kills moss, algae, and lichen at the root not just on the surface. It works on both indoor and outdoor surfaces and is trusted for residential, commercial, and industrial use across New Zealand.
Why people choose it:
- Fast-acting, long-lasting one treatment keeps working long after application
- 3+ year shelf life when stored properly, so buying in bulk never goes to waste
- Multi-surface safe for roofs (except asphalt shingles), brickwork, fences, driveways, decks, pathways, siding, walls, and indoor areas
Dilution guide:
| Job | Mix Ratio |
|---|---|
| General cleaning | 1 part product : 25 parts water |
| Heavy-duty (established moss/algae) | 1 part product : 20 parts water |
| Light duty / indoor mould | 1 part product : 50 parts water |
Best Application Methods
How you apply it makes a big difference to coverage and results. Here are the two most effective methods:
1. Water Blaster Foaming Lance
A foaming lance attachment on your water blaster is the fastest way to treat large driveways, paths, and roof areas. The foam clings to vertical and sloped surfaces (like roof tiles) far better than a thin liquid spray, giving the product more contact time to work before it runs off. Ideal for bigger jobs where speed and even coverage matter.
2. Back Pack Sprayer
For more controlled, precise application especially on fences, brickwork, garden edges, or smaller driveway sections a backpack sprayer is the go-to tool. It gives you full control over where the product lands, which is handy near garden beds, painted surfaces, or areas you want to avoid overspray on.
Quick tip: Whichever method you use, apply on a still, dry day with no rain forecast for at least 24–48 hours, so the treatment has time to work before it's washed away.
How to Apply It
Outdoors (roofs, driveways, decks, fences, paths):
- Mix to the right dilution and load into your water blaster foaming lance or backpack sprayer.
- Apply evenly and leave for several days ( depends on surface type and condition) don't rinse straight away, the product needs time to work.
- Once it's dwelled, brush off dead moss/lichen with a stiff broom, or rinse with your water blaster.
Indoors areas:
- Apply the light-duty mix and keep the surface damp during treatment.
- Sponge off residue once the dwell time is done.
Be patient: Lichen and heavy algae can take 1–2 weeks to fully die off. Don't scrub or re-treat too early — it's still working.
Roofs vs Driveways – Quick Guide
🏠 Roofs
- Spray the solution evenly over the affected area.
- Leave the treatment to work for several days to kill moss, mould, algae, and lichen.
- Dead growth will gradually weather away naturally, or can be gently rinsed or brushed off if required.
- Not suitable for asphalt shingles.
🚗 Driveways
- Spray the solution generously, ensuring it reaches joints, cracks, and porous areas where moss commonly regrows.
- For heavy moss and algae growth, use a 1:20 dilution for best results.
- Allow the solution time to work. Pressure washing or rinsing may be required to remove heavy dead growth and restore the surface.
FAQs
How long until I see results?
Days for surface moss and algae; up to 1–2 weeks for lichen and heavy growth.
What's the best tool to apply it with?
A water blaster foaming lance for large areas and roofs, or a backpack sprayer for precise, smaller-area application.
Get rid of moss, algae, and lichen for good. Shop Moss & Mould Killer in 5L, 4×5L (20L), and 8×5L (40L) sizes — perfect for everything from a single driveway to full commercial property maintenance.