Removal of algae, etc., from concrete slabs

[faraday]

A fair amount of algae and moss has built up on a path in a shady part of my garden, and I am trying to remove it. I have tried Jeyes Fluid, but it does not remove the growth that is firmly attached to the concete. I have found some chemicals on the internet that cost up to �20 for a 5 litre can. As I have only about six 2 ft x 1 ft 6 in slabs to deal with I don't really want such a lot of treating fluid.

I would appreciate some advice on suitable products to use that are not expensive. I suppose I may have to make several applications if I don't go for a strong chemical.

[Toureman]

I always use a jet washer, never fails.

[chitchat]

I used bleach, squirt it directly onto the path, slosh some warm water and scrub well with a good yard brush. Worked for me. Hard work mind!

[chevrolet1.8]

yep i'm with Toureman, i use a karcher jetwasher, it rips it up!

[woodchopper]

When you've blasted the algae away cover it over with another solution of Jeyes fluid - it will kill any remaining slime and keep it away for longer than powerwashing alone will - there is a product on the market specifically aimed at killing slime/algae/moss callled Armillatox available at garden centres which is formulated better at killing slime than Jeyes fluid. Smells pretty much the same but as I said is better at it.

[faraday]

Many thanks to you all for your advice. To those who suggested a jet washer, all I can say is that my gardener used his earlier to clean the greenhouse, but I forgot to get the path done at the same time. I would not want it used now with plants nearby.
I found a yard brush, as recommended by Jeyes and mentioned by Chitchat, not stiff enough to remove stuborn deposits. Today I thought I would try a wire brush, which I fixed to an short piece of angled tubing. I used it kneeling and applied the force of two arms to remove the stuff the yard brush wouldn't. Magic!!
I will get some Armillatox, as suggested by woodchopper, to try next time.

[Thunderbird+]

Personally I'd go with woodchopers suggestion of Armillatox, it was originally developed as a fugicide for killing honey fungus and was found to be ideal for killing slippery algae covered surfaces.
You could get a scrubing brush type thing on a broom handle to save your back and knees and just wash it off later with a garden hose with your thumb over the end or a multi spray nozle fitted