Sodium Hypochlorite Patio Cleaner 4 x 5 litres of Industrial-Strength Algae & Black Spot Remover – Powerful Driveway & Paving Cleaner – Professional Outdoor Cleaning Solution for Concrete

I use this cleaner mainly for my block paving driveway that is prone to weeds and moss growing between the blocks. It is best diluted 1 part cleaner to 4 parts water, so I use a litre of the hypochlorite and 4 litres of hot water in a watering can and carefully cover the entire area to be treated. Be aware this is a strongly corrosive product so wear protective clothing to avoid splashing on your skin, especially hands and eyes. It acts as both a herbicide and cleaner. Your paving will be cleaner and clearer after use - normally a few days later. The great thing about sodium hypochlorite is it degrades to salt so should not harm the environment in the same way as some other chemicals. It also works really well on cement paving slabs, porous stone window sills and curbs. Also be aware when pouring it can splash a little when the container is quite full, so pour carefully or use a funnel. Overall this is a great product and most of the time beats harsh pressure washing.

Arrived a day early, which was great, looks like a good product. Will update at the weekend when I get to use it.

I liked that it worked very quickly unlike less strong formulas that take days to show an effect. This is good when you only get a few days between rain showers. The downside is you really need to wear a pro quality respirator with appropriate cartridges as the stuff smells like ten swimming pools and is not a good thing to breath in. Goggles and gloves and old clothes essential. Full bio suit not an overreaction. But good when you've gone through the alternatives and still have an algae and moss issue on a large area.

Very strong and effective

Fantastic stuff! I have a 1970s property that’s probably never seen a clean roof since the day it was installed. After biting the bullet to have scaffold erected I saw the opportunity to do so myself. I bought 4 bottles. I used roughly 2 bottles per side (see images for size of roof - roughly 8m long). Day 1; About 2pm I sprayed on neat using a cheap pump spray from a reputable trade store for about £9. Left overnight. Day 2; everything that was living no longer was.... Unfortunately I never took a before photo but trust me it’s like day and night. I just thought I would post this because so many say not to use it neat and there’s no harm in doing so just make sure you MUST use goggles and some form of respirator (there’s no cure for chemical inhalation and this is the equivalent of bleach!!!)... Oh and wear plastic bags inside your socks if there’s any chance of your sock soaking it up like mine 😬 trust me it stings the skin for a little while depending on exposure! I washed mine as soon as I felt the burning sensation and no long term damage. Don’t be deterred by DELIVERY as I ordered Friday and it arrived Monday when it was estimated from Monday week! Fantastic product and fantastic service. Just to clarify I pressure washed it on day 2 once it was all dead. The dead looking side (on the left) is after use of product on day 2 prior to jet washing. If your going to jet wash only do it aiming down from the ridge (hence the scaffolding) not up at the ridge as water ingress is highly likely. Hope this helps someone on the fence!

Excellent Results easy to use Paths cleaned best eve

Check out my before and after photos! That's all I need to say. I had a particularly bad case of black spot and it took several applications, but I got there in the end.

In the past We have spent hours pressure washing the patios in our garden using all sorts of different products and got poor results despite our efforts This product is amazing very little work NO PRESSURE WASHING and unbelievable results we are so pleased still have some remaining black spots but patios are all over 25 years old but they have really improved beyond expectations Would highly recommend this We used equal parts water to product and in some areas stronger but it is worth the cost we have purchase 3 x 4 but we have5 areas plus paths so pleased