Page 1 of 1

More a general problem than a growing one

Posted: Thu Nov 28, 2019 1:32 pm
by Primrose
Any advice on how/what I can use to get rid of these unsightly black mould patches on our yellow coloured paving slabs?

And is now a goos time to try and do it with winter ahead or should I wait until spring when the worst of the bad weather is behind us? The recent rains seems to have made them worse.

Jet washing removed all the cement in the cracks on a previous occasion so don't want to go this route again.

Re: More a general problem than a growing one

Posted: Thu Nov 28, 2019 1:58 pm
by oldherbaceous
Dear Primrose, i'm surprised the mould just doesn't fall downwards... :)

All joking apart, Wet&forget is the stuff to get...dilute it down, apply with a watering can with a rose on, then I use a soft broom to brush it about, just to make sure it gets into everything. Might be a little late in the year, as the surface should be dry when applied and stay dry for a good while after it has been applied... but I would still be tempted to try it, as long as rain isn't forecast.

Re: More a general problem than a growing one

Posted: Thu Nov 28, 2019 3:07 pm
by Geoff
There are a few similar things about, I use one of almost the same name on cobbles, Simply Spray and Walk Away. Don't know if the Black Spot Remover is any more effective for the specific problem. Got a 5% off popup today by the way.

https://www.hygienesuppliesdirect.com/c ... o-cleaners

Re: More a general problem than a growing one

Posted: Thu Nov 28, 2019 4:14 pm
by robo
You could use brick acid it’s meant for cleaning cement off brickwork so should work

Re: More a general problem than a growing one

Posted: Thu Nov 28, 2019 6:55 pm
by sally wright
Do not use Brick Acid on concrete paving slabs, the surface will be ruined and if they are surface coloured then this will come off as well.
Regards Sally Wright..