Recommendation for cleaning up our decks

Forums › Home Workshop DIY › Recommendation for cleaning up our decks

johno1234

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#319349 16-Apr-2025 12:36

Our Kwila decks look like cr@p. Grimy with a bit of mould.

What should we clean them with? I would like to avoid Wet & Forget products due to their massive markups on commonly available chemicals.

Once done i plan to put decking oil on them

TIA…

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Smpl Mnmlst
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#3364646 16-Apr-2025 13:57

Totally agree re WnF - we use the 30 Seconds brand mould remover that is the equivalent to WnF but at a much more reasonable price. These products take a while to do their stuff - apply it and give the deck a bit of a scrub with a short-bristle deck broom while wet then leave it for few weeks.

Whatever you do, avoid water blasting.

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wellygary

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#3364651 16-Apr-2025 14:13

eracode:

Totally agree re WnF - we use the 30 Seconds brand mould remover that is the equivalent to WnF but at a much more reasonable price. These products take a while to do their stuff - apply it and give the deck a bit of a scrub with a short-bristle broom while wet then leave it for few weeks.

Whatever you do, avoid water blasting.

WnF's pricing tier has allowed multiple "off brand" chemical clones to thrive...

There's the local 30Sec, + places like bunnings have Cyclone from Oz and mitre 10 have a home brand...

duckDecoy

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#3364652 16-Apr-2025 14:17

https://www.hamchem.co.nz/chemical-applications/cleaning-products/product/keep-kleen

Basically wet and forget

I checked my last order: $87 excl GST for 5L, and is way more concentrated that W&F

decibel

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#3364664 16-Apr-2025 14:39

johno1234:

...Once done i plan to put decking oil on them…

Just make sure that there is NO linseed oil in that.

tweake

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#3364667 16-Apr-2025 14:45

pams disinfectant (at any grocery store) which is same chem as above.

or napisan or any "clean with oxygen" cleaner. it will bleach it. use a deck broom.

mentalinc

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#3364670 16-Apr-2025 14:50

duckDecoy:

https://www.hamchem.co.nz/chemical-applications/cleaning-products/product/keep-kleen

Basically wet and forget

I checked my last order: $87 excl GST for 5L, and is way more concentrated that W&F

What's the required concentration mix for using the 'rapid' applicator?

Happy with the WnF as the time saving of the rapid product is great vs a garden sprayer approach.

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eracode

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#3364672 16-Apr-2025 14:54

tweake:

pams disinfectant (at any grocery store) which is same chem as above.

or napisan or any "clean with oxygen" cleaner. it will bleach it. use a deck broom.

Except those are an expensive way to access the active ingredient on $/volume basis.

Sometimes I just sit and think. Other times I just sit.

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Bung

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#3364674 16-Apr-2025 14:58

tweake:

pams disinfectant (at any grocery store) which is same chem as above.

or napisan or any "clean with oxygen" cleaner. it will bleach it. use a deck broom.

Pam's is about 1/30 th of the concentration.

Oxy cleaners as recommended in the Australian Renovate forums. You know how Aussies love their decks.

fearandloathing

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#3364675 16-Apr-2025 15:02

I know you said no wet and forget products, but their ‘hit the deck’ is great for cleaning pine decks. I don’t think it is as expensive as their other products.

jonathan18

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#3364725 16-Apr-2025 15:11

Sodium percarbonate’s another option; I just buy it off TM: https://www.trademe.co.nz/a/search?search_string=sodium%20percarbonate

johno1234

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#3364733 16-Apr-2025 15:42

Thanks!

I am thinking Sodium Percarbonate. Have googled that up and for my approx 100m2 of decks will need 20L of solution at 50g/L so exactly 1kg of powder.

Have also read that subsequent wash with Oxalic acid will brighten the timber's appearance by reducing greying. Anyone tried this? Being acid it would be neutralised by any residual sodium percarbonate?

trig42

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#3364737 16-Apr-2025 15:47

I've used Napisan - dissolve in warm water, wet section of deck, scrub with decent short bristle broom, rinse off.

Works just as well as Hit the Deck.

jonathan18

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#3364744 16-Apr-2025 16:23

trig42:

I've used Napisan - dissolve in warm water, wet section of deck, scrub with decent short bristle broom, rinse off.

Works just as well as Hit the Deck.

My mate Gemini reports:

The main active ingredient in Napisan is sodium percarbonate. This compound releases active oxygen, which helps to lift out stains and remove odors. Napisan also often contains Tetraacetylethylenediamine (TAED), which boosts stain removal, even at lower temperatures. Additionally, some formulations may include enzymes to break down food stains and outdoor stains.

TBH, I’ve not researched whether those additional ingredients it may contain make a meaningful difference to it as a deck cleaning product, but I’ve been happy with using the base ingredient. That said, a couple of years back I did use an additional product for the worst part on the deck; something from Bunnings, which definitely worked better (but would have been so expensive if used for the whole deck!).

But, yep, a decent amount of elbow grease is still required with napisan/sodium percarbonate.

panther2

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#3364745 16-Apr-2025 16:29

Biosheild has worked well for me

https://bio-shield.co.nz

MikeFly

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#3364749 16-Apr-2025 16:51

Sodium Percarbonate in warm water and a stiff broom. PGG Wrightsons sell it in bulk, cheap.

Also a great . safe, general purpose cleaner, stain remover. Used as a sanitizer in brewing.

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