Cleaning paving slabs
 

We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

--
Frank

Cleaning paving slabs
 

On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?


Bac 50?

https://mistralni.co.uk/products/c10...um-chloride-ba

I've used it to remove algae on a transparent plastic roof. Sprayed on
and left for a week or two before washing again with clean water from a
hose.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Cleaning paving slabs
 

On Fri, 06 Nov 2020 22:27:09 +0000, Chris Hogg wrote:
On Fri, 6 Nov 2020 20:59:05 +0000, F news@nowhere wrote:


We've got a patio made up of light coloured concrete paving slabs
with a
slightly rough texture. I've used a Karcher power washer to remove
the
compost that the resident gardener has managed to tread into them
but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?


'Patio Magic' aka Benzalkonium chloride. It contains the same stuff
as
Alan recommended, but with a more pronounceable name, and is more
dilute! Take your pick from e-bay suppliers here
https://tinyurl.com/y56baf45


+1; good stuff. Wilko and Robert Dyas sell it for something like £8.

Cleaning paving slabs
 

On 06/11/2020 21:28, alan_m wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?


Bac 50?

https://mistralni.co.uk/products/c10...um-chloride-ba

I've used it to remove algae on a transparent plastic roof. Sprayed on
and left for a week or two before washing again with clean water from a
hose.

Thanks. It sounds to need some fairly serious [protection when spraying
it. How plant-safe is it?

--
Frank

Cleaning paving slabs
 

On 06/11/2020 22:27, Chris Hogg wrote:
On Fri, 6 Nov 2020 20:59:05 +0000, F news@nowhere wrote:

We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

'Patio Magic' aka Benzalkonium chloride. It contains the same stuff as
Alan recommended, but with a more pronounceable name, and is more
dilute! Take your pick from e-bay suppliers here
https://tinyurl.com/y56baf45


Bac50 needs to be diluted 10:1 to 20:1 water:BAC50 for this application.
Possibly not that plant friendly.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Cleaning paving slabs
 

On 06/11/2020 22:27, Chris Hogg wrote:

more pronounceable name, and is more
dilute!

Sold on Ebay and elsewhere as easy to pronounce BAC50.


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Cleaning paving slabs
 

On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

Green goes with bleach and heavy power washing. Its the black ones that
are impossible to shift.


--
"A point of view can be a dangerous luxury when substituted for insight
and understanding".

Marshall McLuhan

Cleaning paving slabs
 

The Natural Philosopher wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

Green goes with bleach and heavy power washing. Its the black ones that
are impossible to shift.

Does everyone *really* worry all that much about what colour their
patio paving ends up as it weathers? Our patio paving (two areas
outside sliding doors outside the house and one area round the pond)
just get cleared of the weeds that pop up through the cracks and
that's it. If they go funny colours with lichen or other such things
then that's part of their attraction IMHO.

You don't clean all the funny patches off the bark of beech or silver
birch trees (or do you).

--
Chris Green
·

Cleaning paving slabs
 

On 7 Nov 2020 at 10:43:20 GMT, "Chris Green" wrote:

The Natural Philosopher wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

Green goes with bleach and heavy power washing. Its the black ones that
are impossible to shift.

Does everyone *really* worry all that much about what colour their
patio paving ends up as it weathers? Our patio paving (two areas
outside sliding doors outside the house and one area round the pond)
just get cleared of the weeds that pop up through the cracks and
that's it. If they go funny colours with lichen or other such things
then that's part of their attraction IMHO.

You don't clean all the funny patches off the bark of beech or silver
birch trees (or do you).

That's how I feel about the 3cm deep moss on my outside concrete. Not
everyone agrees with me though, especially the hedge sparrows which rip out
great chunks of it looking for invertebrates.

--
Roger Hayter

Cleaning paving slabs
 

On Sat, 7 Nov 2020 10:43:20 +0000, Chris Green wrote:

Does everyone *really* worry all that much about what colour their
patio paving ends up as it weathers?

Only when it's algae and wet, when the coeffcient of friction drops
close to zero...

--
Cheers
Dave.

Cleaning paving slabs
 

On 07/11/2020 10:43, Chris Green wrote:


Does everyone *really* worry all that much about what colour their
patio paving ends up as it weathers? Our patio paving (two areas
outside sliding doors outside the house and one area round the pond)
just get cleared of the weeds that pop up through the cracks and
that's it. If they go funny colours with lichen or other such things
then that's part of their attraction IMHO.

You don't clean all the funny patches off the bark of beech or silver
birch trees (or do you).



You don't normally walk on the lichen or algae on the bark of trees.
Algae on paving slabs can be very slippery when wet.


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Cleaning paving slabs
 

On 07/11/2020 09:37, The Natural Philosopher wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

Green goes with bleach and heavy power washing. Its the black ones that
are impossible to shift.

We have black too. Forgot to mention that.

--
Frank

Cleaning paving slabs
 

On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

Thanks, all. It looks like an order for BAC50 will be going in.

--
Frank

Cleaning paving slabs
 

On 07/11/2020 14:17, F wrote:
On 07/11/2020 09:37, The Natural Philosopher wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs
with a slightly rough texture. I've used a Karcher power washer to
remove the compost that the resident gardener has managed to tread
into them but there's a green stain (algae?) that's pretty resistant
to removal.

Anyone got any suggestions on what might shift it?

Green goes with bleach and heavy power washing. Its the black ones that
are impossible to shift.

We have black too. Forgot to mention that.

If BAC50 shifts it, please let us know.
I've tried everything


--
€œIt is not the truth of Marxism that explains the willingness of
intellectuals to believe it, but the power that it confers on
intellectuals, in their attempts to control the world. And since...it is
futile to reason someone out of a thing that he was not reasoned into,
we can conclude that Marxism owes its remarkable power to survive every
criticism to the fact that it is not a truth-directed but a
power-directed system of thought.€�
Sir Roger Scruton

Cleaning paving slabs
 

On 07/11/2020 14:20, F wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

Thanks, all. It looks like an order for BAC50 will be going in.

https://job-prices.co.uk/best-moss-killer/

Lots of sellers on Ebay. Price last December was around £25 for 5
litres (incl postage) from many sellers. During the last lock-down the
price rose by 3x to 4x and now back to around £30 for 5 litres from some
sellers. Smaller quantities are available but postage probably forms a
disproportionate percentage of the overall cost.


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Cleaning paving slabs
 

On 07/11/2020 15:02, alan_m wrote:
On 07/11/2020 14:20, F wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

Thanks, all. It looks like an order for BAC50 will be going in.

https://job-prices.co.uk/best-moss-killer/

Lots of sellers on Ebay.Â* Price last December was around £25 for 5
litres (incl postage) from many sellers. During the last lock-down the
price rose by 3x to 4x and now back to around £30 for 5 litres from some
sellers.Â* Smaller quantities are available but postage probably forms a
disproportionate percentage of the overall cost.


The problem is that this says its to treat moss. It says nothing about
algae.
I hope that it works But I fear it may not



--
€œA leader is best When people barely know he exists. Of a good leader,
who talks little,When his work is done, his aim fulfilled,They will say,
€œWe did this ourselves.€�

ۥ Lao Tzu, Tao Te Ching

Cleaning paving slabs
 

On 07/11/2020 15:18, The Natural Philosopher wrote:



The problem is that this says its to treat moss. It says nothing about
algae.
I hope that it works But I fear it may not




In the first link I gave (random listing) it says

I have personal experience of it effectively clearing a plastic roof of
a thick film of green algae.

From
https://hlssupplies.co.uk/bac50-biocide-blog

"BAC50 is used for removing algae, moss and mould and preventing
regrowth. This BAC50 solution is a professional grade and is still
effective in dilutions up to 1%. We recommend a finished solution
between 2.5% and 5% (Depending on the substrate being treated)"
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Cleaning paving slabs
 

On 07/11/2020 15:29, alan_m wrote:
On 07/11/2020 15:18, The Natural Philosopher wrote:



The problem is that this says its to treat moss. It says nothing about
algae.
I hope that it works But I fear it may not




In the first link I gave (random listing) it says

Quote:

Used in fungicidal products to kill fungus, mould and algae.

I have personal experience of it effectively clearing a plastic roof of
a thick film of green algae.

From
https://hlssupplies.co.uk/bac50-biocide-blog

"BAC50 is used for removing algae, moss and mould and preventing
regrowth. This BAC50 solution is a professional grade and is still
effective in dilutions up to 1%. We recommend a finished solution
between 2.5% and 5% (Depending on the substrate being treated)"

Good. Now will it clear black algae? I have no problem clearing green
and red algae and moss with a pressure washer...


--
"What do you think about Gay Marriage?"
"I don't."
"Don't what?"
"Think about Gay Marriage."

Cleaning paving slabs
 

On Saturday, November 7, 2020 at 4:52:55 AM UTC-6, Roger Hayter wrote:
On 7 Nov 2020 at 10:43:20 GMT, "Chris Green" wrote:

The Natural Philosopher wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?

Green goes with bleach and heavy power washing. Its the black ones that
are impossible to shift.

Does everyone *really* worry all that much about what colour their
patio paving ends up as it weathers? Our patio paving (two areas
outside sliding doors outside the house and one area round the pond)
just get cleared of the weeds that pop up through the cracks and
that's it. If they go funny colours with lichen or other such things
then that's part of their attraction IMHO.

You don't clean all the funny patches off the bark of beech or silver
birch trees (or do you).

That's how I feel about the 3cm deep moss on my outside concrete. Not
everyone agrees with me though, especially the hedge sparrows which rip out
great chunks of it looking for invertebrates.

--
Roger Hayter

The cats don't eat the sparrows? They would eat a komodo dragon

we sold our house and I had a great deal of agitation about what to do about two patios (one concrete and brick) that were not cosmetically special. Had a friend who wanted to power wash, but some of the bricks were loose and I did not think that was a good idea. These advices are good for the next set of patios I have to sell. The buyer took the house s is, making it all moot.

Now all I have is a small balcony, which is getting weathered looking after ten years, but in addition, post hurricane last week seems to have developed a nasty crack.

I have been hearing a cat since i moved back

I figured he was on someones Balcony

Nope he is roaming around

We have a leash law in our leases

I do not know why the cat is allowed

Also this may be the ugliest cat on planet esrth

It is orange, and looks like a huge furry shoe box on legs

Bet he is ten years or more old, his fur looks crazy not well groomed

I cannot help but wonder if he is feral

I would still hang some suet from a basket for the birds especially with winter coming up

I guess I will clean it up some day but not now.

That's going to make the balcony even messier.

mk5000

So unaware
As one-by-one your subjects
Vanish into air
Chatter to the wind==King Of Insects (Red Sparrow Remix) Lyrics by Assemblage 23

Cleaning paving slabs
 

On Saturday, November 7, 2020 at 6:19:44 AM UTC-6, alan_m wrote:
On 07/11/2020 10:43, Chris Green wrote:


Does everyone *really* worry all that much about what colour their
patio paving ends up as it weathers? Our patio paving (two areas
outside sliding doors outside the house and one area round the pond)
just get cleared of the weeds that pop up through the cracks and
that's it. If they go funny colours with lichen or other such things
then that's part of their attraction IMHO.

You don't clean all the funny patches off the bark of beech or silver
birch trees (or do you).



You don't normally walk on the lichen or algae on the bark of trees.
Algae on paving slabs can be very slippery when wet.


--

for sure, I have fallen on that stuff.

Ther's a dead tree way out in the back of my yard, out of the way, cant even barely see it from my house, which is covered in this stuff, but i have never walked on it

And exactly what I considered doing

But I have so many neighbor cats in my yard I hate them

I think its so rude to let your cat wander all over everybody elses property
Its YOUR cat, I dont want him here!

If I let a dog do that Id get arrested in less than 5 minutes

I want to get a Komodo dragon and let him wander all over THEIR yards

mk5000

Old pond
Frog jumps in
Sound of water--Matsuo Bash�

Cleaning paving slabs
 

On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?



I use diluted bleach in a large watering can to clean my patio, and have
done so for years. It's as clean now as it was just after it was first laid.

Cleaning paving slabs
 

On 07/11/2020 14:54, The Natural Philosopher wrote:
On 07/11/2020 14:17, F wrote:
On 07/11/2020 09:37, The Natural Philosopher wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs
with a slightly rough texture. I've used a Karcher power washer to
remove the compost that the resident gardener has managed to tread
into them but there's a green stain (algae?) that's pretty resistant
to removal.

Anyone got any suggestions on what might shift it?

Green goes with bleach and heavy power washing. Its the black ones that
are impossible to shift.

We have black too. Forgot to mention that.

If BAC50 shifts it, please let us know.
I've tried everything


have you tried thin bleach as demonstrated on various Youtube videos
although many example swimming pool chlorine.

I have had a huge amount of black and green lichen on concrte pavers and
simply brushed on the bleach over a slightly dampened surface on a sunny
day and kept it damp for the rest of the day. If no kids or pets around
I left it and 98% has gone in one or two sessions. Exception is the
crumbly edges which are a bugger.

Oddly, as mentioned in one video, it seems to go on having an effect for
a while afterwards. Good luck

Cleaning paving slabs
 

On 08/11/2020 10:42, Ian wrote:
On 07/11/2020 14:54, The Natural Philosopher wrote:
On 07/11/2020 14:17, F wrote:
On 07/11/2020 09:37, The Natural Philosopher wrote:
On 06/11/2020 20:59, F wrote:

We've got a patio made up of light coloured concrete paving slabs
with a slightly rough texture. I've used a Karcher power washer to
remove the compost that the resident gardener has managed to tread
into them but there's a green stain (algae?) that's pretty resistant
to removal.

Anyone got any suggestions on what might shift it?

Green goes with bleach and heavy power washing. Its the black ones that
are impossible to shift.

We have black too. Forgot to mention that.

If BAC50 shifts it, please let us know. I've tried everything

have you tried thin bleach as demonstrated on various Youtube videos
although many example swimming pool chlorine.

I have had a huge amount of black and green lichen on concrete pavers and
simply brushed on the bleach over a slightly dampened surface on a sunny
day and kept it damp for the rest of the day. If no kids or pets around
I left it and 98% has gone in one or two sessions. Exception is the
crumbly edges which are a bugger.

Add a couple of drops of washing-up liquid to a watering-can of diluted
bleach, and stir it in. The idea is to avoid making it foam, you just
need it to be evenly distributed throughout the bleach solution. It
lowers the surface tension, enabling the bleach solution to penetrate to
places where the high surface tension of water would otherwise limit the
penetrating power of the solution.

Oddly, as mentioned in one video, it seems to go on having an effect for
a while afterwards. Good luck

When the solution dries out, the active ingredient is still there,
re-dampening the treated surfaces or a shower of rain will reactivate it.

Dilute bleach, especially with added washing-up liquid, will kill black
spot and brown spot invasions; it might kill white spot too but the
remains seem to persist.

Unfortunately it doesn't get rid of the blackened areas.

--
Spike

Cleaning paving slabs
 

On 08/11/2020 12:14, Spike wrote:
Dilute bleach, especially with added washing-up liquid, will kill black
spot

No, it wont. Or at least it wont remove the staining.

BTDTGTTS

--
"Women actually are capable of being far more than the feminists will
let them."

Cleaning paving slabs
 

On Sunday, November 8, 2020 at 9:39:31 AM UTC, RobH wrote:
On 06/11/2020 20:59, F wrote:
We've got a patio made up of light coloured concrete paving slabs with a
slightly rough texture. I've used a Karcher power washer to remove the
compost that the resident gardener has managed to tread into them but
there's a green stain (algae?) that's pretty resistant to removal.

Anyone got any suggestions on what might shift it?



I use diluted bleach in a large watering can to clean my patio, and have
done so for years. It's as clean now as it was just after it was first laid.

Moss on tarmac drive was ou problem but sprinkling it with biological washing powder (Aldi's cheapest) wiped it out. Good for a few year

Cleaning paving slabs
 

On 08/11/2020 12:37, The Natural Philosopher wrote:
On 08/11/2020 12:14, Spike wrote:

Dilute bleach, especially with added washing-up liquid, will kill black
spot

No, it wont. Or at least it wont remove the staining.

BTDTGTTS

I get an old trigger-pack - mostly the tops are a sort of bayonet
fitting and are easily replaced once removed - I flush it out then add 1
part of thick bleach to 4 parts of water and two drops of washing-up
liquid; then replace the top and repeatedly invert to mix the contents.

I've used this to remove several hundred black spot (and brown spot)
growths from both my and my neighbours footpaths, and there's no sign
they were ever there, and they have never returned. I treated them every
couple of weeks for three or four treatments.

I think this kills white spot too, but they seem never to fade away;
they are best zapped while very small and this seems to stop them
getting any bigger.


--
Spike