Patio cleaner

Nellie
that is exactly what my brother said to me when I said complained about the black lichen spoiling my otherwise lovely patio.

Are you sure the black spots are not lichen? If so they will do no harm in any of our lifetimes.
If you take a hand lens and look at them very close up they are amazing plants.

jim44

YES

I have tried everything to remove the strange black spots that appeared on them to be a sort of growth on my flagstones....all types of stone cleaning fluid.power washer ..bleach..etc no results at all apart from my grinder what else can i try ???????
Jim

I have Indian sandstone, and was recommended to use a solution of very dilute bleach. I just sprinkle it from a watering can, or a sprayer, leave for 20 minutes or so then squirt it off with a hose. It hasn't damaged the surface at all, but gets rid of any greening from algae etc. I found the pressure washer hard work and it damaged the pointing between the stones, also tended to lift the sandstone layers.

I use a power cleaner for my stone patio, block paved drive and concrete path annually and the results are amazing.
It does clean everything well but it is hard work and does take time but the only thing it doesn't clean off is lichen which you would need a chemical cleaner to remove.
I am very concerned about using strong cleaners so have put off using them.

Been and bought a compact Karcher. My patio looked like dirty pavement flagstones. I was amazed to find they are a lovely sandy colour. The muck had to be seen to be believed!
I'm very impressed with what such a small machine can do. We hired one once, ages ago and it was so unwieldy it weighed a ton. They have changed so much.

I would also recommend a pressure washer supernanauna1 - I bought a Karcher and it's one of the best investments for home care; no chemicals (you can have a detergent but I've never found I've needed to use that) and if you get one that has a good, strong jet, you can clean the upstairs windows too

I had my drive cleaned by a professional last week. He used a power jet which was very effective and then brushed fresh sand in between the bricks. He ended up splattered with mud from head to toe. Windows ditto. We paid £240 but it would depend on the size of drive of course. I wouldn't want to tackle the job myself.

Roses what kind of pressure washer did you get? Seriously thinking of one of the smaller types, hoping they have enough power. Could you use it to wash the car too? Was going to hire one but they are very heavy and my garden is on a slope.

I used to use a box of cheap washing poweder, Daz or the like and throw it around the patio and concrete drive. Give it a light spray with the hose and let it sit for a couple of hours. Then go over it with a hard bristled brush. This worked but was hard work.

Now DH gets stuff from the Farm Supply Shop that they use to clean out the dairy and puts it into the power washer. I think that putting it in a bucket of water and slooshing it over a patio could have a good effect, leave it for a week while and then use a hard bristle yard brush.

I use dilute bleach. Reading the previous comments has made me wonder if I'm damaging our Indian stone path. Any comments please?

We bought a pressure washer last year; it's wonderful! Thought the patio was composed of grey stones only, but once washed it showed that half were a golden colour, amazing.

Message deleted by Gransnet for breaking our forum guidelines. Replies may also be deleted.

The one at the back is 12 x 12 blocks - some are red and the others grey. I would also like to clean the front pavement which is red brick. It all looks just grubby. Thanks.

I used to do mine on hands and knees with a wire brush - hard work but cheap and effective! I now have a pressure washer which has a patio cleaning attachment. This causes less splash and does a fantastic job, as quick as vacuuming a room. Merlot is right, there is dirty water to sweep away, but I can't use chemicals as I have cats. The initial outlay was a bit expensive but will last a lifetime I hope.

If you don't already have one, can you beg, borrow or steal a pressure washer, super? You won't need any chemicals that will harm plants but you will have a bit of sludge to accommodate or clean away at the border of your patio.

It would depend on what sort of material your patio is paved with.

What is on it that needs cleaning off? Many patio cleaners are basically dilute acids. I would generally steer clear of using them on any limestone or your patio will (slowly) fiz away.

Some sandstone contains a lot of shelly fragments as well and in others the sand grains are "cemented" together by the lime that flows into them when they are formed. Using such cleaners on the could theoretically dissolve out the limestone and loosen the sand grains.

Care is needed. really you need to try out a cleaner on a small sample of whatever your patio is made of but its hard to get small samples of cleaner to do it with.
Geologists tend to carry small bottles of 10% Hydrocloric Acid to test if rocks are limestone, and that fizzes wonderfully, so anything stronger could cause a lot of trouble.