Recommendation for cleaning up our decks

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

johno1234

3352 posts

Uber Geek
+1 received by user: 2843

#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…

1 | 2

Smpl Mnmlst
9333 posts

Uber Geek
+1 received by user: 6200

ID Verified

Trusted

Lifetime subscriber

#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.

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

wellygary

8810 posts

Uber Geek
+1 received by user: 5287

#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

946 posts

Ultimate Geek
+1 received by user: 432

Subscriber

#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

335 posts

Ultimate Geek
+1 received by user: 224

#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

2641 posts

Uber Geek
+1 received by user: 1137

#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

3384 posts

Uber Geek
+1 received by user: 1023

Trusted

#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.

CPU: AMD 5900x | RAM: GSKILL Trident Z Neo RGB F4-3600C16D-32GTZNC-32-GB | MB: Asus X570-E | GFX: EVGA FTW3 Ultra RTX 3080Ti| Monitor: LG 27GL850-B 2560x1440

Quic: https://account.quic.nz/refer/473833 R473833EQKIBX

New World

Shop on-line at New World now for your groceries (affiliate link).

eracode

Smpl Mnmlst
9333 posts

Uber Geek
+1 received by user: 6200

ID Verified

Trusted

Lifetime subscriber

#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.

Bung

6733 posts

Uber Geek
+1 received by user: 2926

Subscriber

#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

537 posts

Ultimate Geek
+1 received by user: 206

ID Verified

Lifetime subscriber

#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

7415 posts

Uber Geek
+1 received by user: 2850

ID Verified

Trusted

#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

3352 posts

Uber Geek
+1 received by user: 2843

#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?

Dyson

Shop now for Dyson appliances (affiliate link).

trig42

5889 posts

Uber Geek
+1 received by user: 2094

ID Verified

#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

7415 posts

Uber Geek
+1 received by user: 2850

ID Verified

Trusted

#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

385 posts

Ultimate Geek
+1 received by user: 143

#3364745 16-Apr-2025 16:29

Biosheild has worked well for me

https://bio-shield.co.nz

MikeFly

192 posts

Master Geek
+1 received by user: 140
Inactive user

#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.

1 | 2