Green patio!

[ratchers]

Had our conservatory knocked down this summer and a proper extension built with french doors out to a newly built patio.

Problem is the grouting/pointing is going green, even some of the flags are getting a bit that way.

So how or what do I use to get rid of said greeness, help please.

[wyn]

Hypochlorite from a farm shop.

Put it on with a watering can. then wash it off next day. it should kill off that sort of stuff.

[Keith RW]

Do mine once a year with cheapest bleach from Aldi, 50/50 mix and applied lightly with 5l pressurised garden spray, all gone next day if not same day

[morgan]

I wouldn't use brick acid, especially if the slabs are composite ones, as it will take the colour off them. I would just use a powerwasher and scrub them with a bit of bleach on any stubborn bits. There is a brush on silicone sealent you can get, that soaks in and would stop the green slime taking a foothold. But try a capful in a hidden spot to make sure it looks ok, as the sealents can darken the paving.

[ditchman]

perhaps a light spray with a copper based solution 3 times/years ?

[Spr1985]

When I worked in landscaping we would presure wash and then seal it, I used to apply the sealant with a paint roller, I believe it was Thompson wet look sealer that we used.