D-Mould
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Timber Protection

D-Mould

A water-based mouldicide and algaecide for exterior surfaces. Dilute, brush or spray it on, scrub — it kills the mould and algae, and weathering lifts the discolouration.

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500 mL jar of concentrate

↓ Safety Data Sheet ↓ Technical Data Sheet

Treats: Mould and algae on exterior surfaces
Use on: Timber, masonry, render and paving
Format: Water-based concentrate. 500 mL makes 10 L.
Not for: Rot, borer or termites — it isn't a timber preservative.

Need advice? Call 03 9532 0679.

Directions for use

Preparing the timber, then applying

Before you start

Lift heavy staining firstScrubbing a badly discoloured surface with household bleach or oxalic acid will clean it instantly. D-Mould then deals with the organism underneath.
Rinse and let it dryRinse the bleached area with plenty of clean water and allow it to dry before treating.
Test a patchOn paintwork or a finished surface, try a small hidden area first.

Applying D-Mould

Read the pack directions before use.

Mix the concentrateMix the 500 mL of D-Mould concentrate into 10 litres of water.
Apply generouslyBrush, roll, spray or mop a generous application onto the surface to be treated.
Scrub the growthScrub the mould- or algae-affected surface with a nylon brush or a stiff broom.
Leave it to workOnce applied, D-Mould kills any existing mould and natural weathering removes the discolouration over a period of time.

Application rate

Coverage and re-treatment.

Item	Rate
Dilution	500 mL concentrate to 10 L water
Coverage	5–10 m² per litre, by surface porosity
Heavily infested surfaces	Re-treat 3–6 months after the first application
Prevention	Re-apply every 1–2 years

Safety & hazards

Safety directions and first aid

Safety directions

Avoid skin contact by wearing protective clothing. Don't breathe vapour or spray mist.

First aid

If poisoning occurs, contact a doctor or Poisons Information Centre (13 11 26). Eyes: hold eyes open, flood with water for at least 15 minutes and see a doctor. Skin: remove contaminated clothing and wash skin thoroughly with soapy water. Inhalation: remove to fresh air. If swallowed: do not induce vomiting — rinse mouth, give milk, gelatin solution or egg white if available, and transport to hospital immediately.

Full safety directions and first aid are on the product label and the Safety Data Sheet.

Where it goes

Wherever mould or algae has taken hold

D-Mould is for the problem that looks like rot but isn't: green, black or grey growth on a damp, shaded surface. If the timber is soft and crumbling, that's decay — see the preservatives.

Decking & stepsShaded boards that stay damp and go slippery with algae.

Cladding & cedarWestern Red Cedar and other exterior timber blackened by mould.

Paving & pathsConcrete, pavers and brickwork on the shaded side of the house.

Roof tiles & renderTiles, masonry and rendered walls with mould or lichen growth.

Painted surfacesMould on exterior paintwork — test a small area first.

Canvas & synthetic grassShade sails, awnings, tents and artificial turf.

Test firstTest D-Mould on a small area of the surface to be treated, to make sure it has no adverse effect on paintwork or the finish.

Kills the growth, not just the stain

Why it works

Bleach strips the colour and leaves the organism. D-Mould is a mouldicide — it kills the mould and algae on and just under the surface, so the growth doesn't simply come back the next damp season.

A mouldicide and algaecide

The active, benzalkonium chloride, kills existing mould and algae. Natural weathering then removes the discolouration over time.

Concentrate — dilute it

One 500 mL jar makes 10 litres of solution, at 5–10 m² per litre depending on how porous the surface is.

Works on most exterior surfaces

Timber (Western Red Cedar especially), decks, paving, brickwork, tiles, painted surfaces, synthetic grass and canvas.

Technical data

Specifications

Active constituents

Benzalkonium chloride (alkyl dimethyl benzyl ammonium chloride) in a water-based concentrate.

Protects against

Mould and algae on exterior surfaces. It is not a timber preservative and does not treat rot, borer or termites.

Rate, coverage & reapplication

500 mL concentrate makes 10 L. 5–10 m² per litre depending on surface porosity. Re-treat heavy growth after 3–6 months; re-apply every 1–2 years to keep it away.

Pack sizes

500 mL jar of concentrate.

Common questions

Is it rot, or is it mould?

Press the timber. Mould and algae sit on the surface — the wood underneath is still hard. Rot is soft, crumbling or spongy. D-Mould treats the first; the second needs a preservative like No-Rot Gel, and possibly replacement.

Do I have to rinse it off?

No. Apply it, scrub, and leave it to work — it kills the growth, and natural weathering removes the discolouration over time. If you want the stain gone straight away, scrub with bleach or oxalic acid first, rinse, dry, then apply D-Mould.

Will it damage paint or a finish?

It is used on painted surfaces, but test a small area first to be sure it has no adverse effect on the paintwork.

How often will I need to do it again?

Heavily infested surfaces may need a second treatment 3–6 months after the first. After that, re-applying every 1–2 years keeps the mould from coming back.

You might also need

Grey Deck Cleaner

Strips the grey off weathered timber before you oil it.

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No-Rot Gel

If it turns out to be rot, not mould — the brush-on preservative for decay you can reach.

View product

Australian made in Cheltenham, Victoria since 1988 — founded by two CSIRO timber scientists. The whole story →