Removing green algae from paving slabs?

[Pilatus]

We have some paving slabs outside our back door,some becoming dangerously slippery because of a thin coating of green algae acting like grease.
Apart from pressure washing the slab’s clean, is there any way of cleaning them, with any type of “ acid”.
Once cleaned what’s the best way of preventing the algae in the first place.
I am sure many other TFF members have same problem around your houses and farm buildings, “ a nasty accident waiting to happen due to slipping up in a split second with the possibility of fracture or broken bones!!!

 

[davidroberts30]

Spray hypochlorite on them

 

[milkloss]

Simple solution extreme dog stain remover works without pressure washing. Takes a few days. Dog used to slash near the house, where we sprayed this stuff never went green.

bound to be something cheaper around though.

 

[Horn&corn]

Hypo acid a quick fix but then wet and forget off amazon.
steam cleaning also works well

 

[Farmer Roy]

There is a product called “wet & forget”, for removing mould / algae / lichen etc off masonry & concrete.
Just spray it on, takes a while to work, but it does a very good job

 

[Bury the Trash]

yeah common or garden bleach .
prevention anything alkaline i think.
sprinkle of lime every now and then and rinse off .

 

[SilliamWhale]

There is a product called “wet & forget”, for removing mould / algae / lichen etc off masonry & concrete.
Just spray it on, takes a while to work, but it does a very good job

Benzalkonium chloride

 

[Alchad]

Although you said “apart from pressure washing” - I had similar problem outside our back door. Bought a rotating pressure washer attachment for the Nilfisk pressure washer which did an excellent job in cleaning up the paving slabs.

 

[TheTallGuy]

Jeyes fluid, or they also do a patio & decking cleaner

 

[Oliveau]

Although you said “apart from pressure washing” - I had similar problem outside our back door. Bought a rotating pressure washer attachment for the Nilfisk pressure washer which did an excellent job in cleaning up the paving slabs.

I have a similar thing for my Karcher. Very easy to use, and quick and doesn't need any chemical to clean my patio.

 

[pycoed]

Non bio detergent will do it if you have a safe runoff - it won't do a watercourse or a septic tank much good.

 

[DRC]

Have used something called Patio Magic with good results ( Amazon will deliver it as well)

 

[Kidds]

In my experience the dog pee mentioned above would do a better job than Patio Magic.
Pressure washer does do the best job imo.

 

[Lincs Lass]

Dont use bleach or any other acidic cleaning products if its natural stone ,,hot steam pressure washer with a patio brush will shift it

 

[Johnnyboxer]

Spray hypochlorite on them

Deosan does the trick

 

[Wooly]

Wet and Forget

Wet & Forget UK - Mould, Lichen & Algae Remover

Wet & Forget is the ideal cleaning product made from biodegradable solutions for removing Mould, Mildew and Lichen on interior and exterior surfaces.

www.wetandforget.co.uk

It actually works !! One spray a year appears to do the trick

 

[deleted user 837354]

Get some cheap bleach. Leave it on for a time, then scrub with a yard brush and then wash it off thoroughly lest someone/dog walk it into the house. Fudge messing around with concentrated hypochlorite.

 

[davidroberts30]

Get some cheap bleach. Leave it on for a time, then scrub with a yard brush and then wash it off thoroughly lest someone/dog walk it into the house. Fudge messing around with concentrated hypochlorite.

Same stuff

 

[solo]

My wife ought to be a sales person for wet and forget. Last year she did our brick patio and was so impressed with the result, she has become obsessed with removing green and lichen. So far this year she has done her mums, (patio, steps, and flower pots.) my mother‘s, (patio and steps) our (brick patio, back yard and steps) and on a visit to our daughter on Sunday her patio slabs and doorstep also got done.! I’m sure she would travel anywhere in her quest to remove green from hard surfaces, such is the current obsession.

Apparently she’s busy today……doing her mothers drive.

Buying direct from the wet and forget website was cheaper than amazon apparently.

 

[SilliamWhale]

Benzalkonium chloride

All these patio magic/ wet and forget products are that