Wet & Forget Moss, Mould, Lichen & Algae Remover - FAQs

Can I Safely Use Wet & Forget Moss & Mould On ANY Exterior Surface?

How Do I Apply Wet & Forget?

1. Choose a cool dry day to apply it. Make sure there’s no rain forecast for at least 5 hours after application (and be mindful of heavy dew/frosts expected overnight.)

2. Mix the product 1 part Wet & Forget to 5 parts of water - in a garden sprayer. (eg 1L Wet & Forget to 5L water)

3. Saturate the dry surface with the product.

4. Then, just watch it come cleaner, bit by bit as Mother Nature takes over. The weathering process gently takes the decomposing material away bit by bit without scouring the surface it has infested.

5. Only one application!

What Is The Dilution Rate and Coverage Area of Wet & Forget?

Mix 1 part Wet & Forget with 5 parts water. A 5L pack makes 30L of ready-to-use spray, covering 100-300m² depending on the surface. Painted surfaces need less, while porous surfaces like concrete may need more.

When Is The Best Time To Apply Wet & Forget?

On a cool, dry windless day and when no rain is expected for 4-6 hours. Often the evening is best when evaporation of the product is minimal. This will ensure that the surface to be treated stays wet with Wet & Forget for an extended period.

How Long Does Wet & Forget Take To Work?

Results depend on the severity of the growth and how much rainfall there is to wash the surface of dead growth. 

• Light contamination may clear within days, while heavier growths could take 2-3 months. A temporary orange-brown discolouration on concrete is normal and indicates the product is working. 

• Very heavy contamination may take 6-12 months initially. However future cleaning results will be much faster than the initial use.

Will Wet & Forget Affect My Pets?

As with any cleaning product, it’s important to keep your pet off the surfaces until the product is completely dry. This prevents them from licking the formula off their fur or paws. If they accidentally sit or walk through the product before it dries, wash their feet and fur with fresh water. As we like to say “Don’t let your moggy or doggy’s paws get soggy!”

What is the difference between Wet and Forget and Rapid Application?

Why Is Wet & Forget Better Than Other Outdoor Cleaners?

Unlike harsh chemical cleaners, Wet & Forget is a gentle, bleach-free solution that won't harm surfaces. Plus, there’s no rinsing required, saving you time and water. 

Easy to use and with safer ingredients, Wet & Forget is the leading outdoor cleaner for a reason. While the first clean may take time, the results are long-lasting and worth the wait.

How Do I Know If Wet & Forget Is Working?

In some circumstances, you may see an instant reaction. For instance, treated moss often turns brown straight away. Surfaces such as concrete may turn an orange-brown colour after it has been sprayed. This temporary change is a good sign as this is a natural reaction between the growth and the Wet & Forget solution.

How Often Should I Apply Wet & Forget?

An annual spray of Wet & Forget should keep the moss, lichen, algae and mould away. However, if any new growth appears, reapply sooner and keep it at bay.

What Time Of Year Should I Apply Wet & Forget?

There is no definitive time - but of course, all these growths such as lichen, moss, mould and algae appear more in the winter months when the exterior surfaces are damp and wet which are the perfect conditions for these growths to thrive. 

Ideally, apply at the first sign of green growth, to a dry surface. Tackling the problem early makes clean-up much easier! Remember, always apply to a dry surface.

Do You Need To Rinse Off Wet & Forget?

NO! Rinsing this product dilutes it, instead, simply apply it to a dry surface and leave it. Mother Nature will take care of the rest.

Is Wet & Forget A Bleach?

Absolutely not!

What Is The Shelf Life Of Wet & Forget?

Unlike bleach-based cleaners, Wet & Forget has an unlimited shelf life. Always keep the cap done up tightly and the container out of reach of children.

What’s The Difference Between Wet & Forget and Rapid Application?

They are 'sister' products. The ingredients and coverage are the same but the dilution rates are different because the way you apply them is different.  Wet & Forget needs a garden sprayer while Rapid Application needs just a hose to apply.

Important: You can’t use regular Wet & Forget 5L with the 2L Rapid Application Reach Nozzle, it won’t work as the dilution rates are very different.

Coverage of 100-300m2 is the same for both products (depending on porosity and amount of contamination on the surface).

Is There Any Residual Effect With Wet & Forget?

Some of the ingredients remain active if the surface is porous. This helps prevent premature recontamination.

If I’m On Tank Water, Can I Use Wet & Forget On My Roof?

If you’re collecting rainwater from your roof, you can still use our awesome products! Just disconnect your water tank for 3-4 weeks, or until you’ve had a good 36mm of rain. This will make sure all the concentrate and decomposing debris gets washed away before it has a chance to get into your tank.

Can I Change The Specified Ratio's Of Wet & Forget?

Yes! For heavy contamination, use a stronger mix for faster results. For light recontamination on previously cleaned surfaces, a weaker mix is sufficient for effective maintenance.

Do I Have To Use The Whole Bottle Of Wet & Forget In One Go?

No, but good planning is essential. Work to a pattern so you know where you have started and stopped. The product is fine if left in the spray container as it does not deteriorate when it has been diluted. Plus, as the product is not corrosive it won’t damage your sprayer.>

Will Wet & Forget Damage My Plants?

Not unless you are directly spraying it onto the plants.If there’s a chance of overspray onto your plants or grass, water the garden before the application to create a barrier, then water again after spraying to wash away any product.

Will Wet & Forget Remove The Mould From My Timber Decks?

Absolutely! For older, heavily contaminated decks, a light scrub with a brush and warm water after a month may help remove stubborn residue. You'll only need to do this once, then future maintenance is a breeze!heck out Hit The Deck, for a more instant result (although it does involve more elbow grease!)

Will Wet & Forget Remove Moss From Lawns?

Sure will! Firstly lightly water the lawn but not enough to saturate the moss, preferably late in the day when the sun is low so that evaporation is kept to a minimum.Mix a solution of 1 part Wet & Forget to 7 parts water and spot spray the affected areas. Repeat as needed until the moss is under control. In some cases, the grass may show slight burning, but it will recover quickly. Once the moss has died, rake it out and apply lime to the area, as moss often indicates acidic soil.

How Much Wet & Forget Will I Need To Clean My Roof?

The average 3-bedroom tile roof is approx 150m2 but because of the undulations of the tile profile the actual area is a lot bigger. Therefore an average tile/concrete roof would require 2 x 5-litre packs, depending on how porous the surface is and how much biological growth is present.

For an average 3-bedroom tile roof with lichen, you would require 3 x 5-litre packs depending on the total area covered with lichen.

How Do I Remove Lichen From My Roof?

For Lichen removal: For best results mix the Wet & Forget and spot spray the lichen, leave for 10-15 minutes and then respray the lichen and the entire roof to ensure the plant absorbs the Wet & Forget thoroughly. The first application is to dissolve the waxy surface. The 2nd spray will then penetrate the lichen.

How Do I Remove Moss & Mould From My Roof?

For green moss and black mould, one application is normally sufficient.