ok to power wash cobblelock driveway ?

Mad_maxx

i need to clean the driverway and surrounds of my mothers new house , its all a sort of reddish brown colour but quite dirty after the winter , a lot of trees as well so quite sheltered

i presume using a honda engine power washers is a bad idea ?

would a lower strength power washer do or is it best to spray with some sort of bleach ( with a knapsack - budget sprayer ) and simply brush it off a week later while just using a garden hose ?

read different reports , some saying its fine to use a pressure washer , some saying it will ruin it ?

Reckless Abandonment

Go for it . The more powerful the better. Personally I don't use any chemicals when I do it . But it can help removing stubborn stains. Id wash it first and see how it goes.

beggars_bush

you might need to feed silica sand down between the cracks with a brush afterwards. that is generally what keeps the weeds down

Stihl waters

Leave the chemicals in the container, a petrol washer should be more than adequate, you wont damage the cobblestones as I have them around my house and do it twice a year with no adverse effects

Mad_maxx

Stihl waters wrote: »

Leave the chemicals in the container, a petrol washer should be more than adequate, you wont damage the cobblestones as I have them around my house and do it twice a year with no adverse effects

what PSI is your washer ?

hire centre have up to 3000 PSI , i have an electric 1500 PSI myself

Stihl waters

Mad_maxx wrote: »

what PSI is your washer ?

hire centre have up to 3000 PSI , i have an electric 1500 PSI myself

I've a 2500, I hired a 3000 the last time as my own was out of action at the time, the 3000 is some beast to clean around a house, I wouldn't use it on the walls, just the paths and driveway as it's so powerful

Mad_maxx

Stihl waters wrote: »

I've a 2500, I hired a 3000 the last time as my own was out of action at the time, the 3000 is some beast to clean around a house, I wouldn't use it on the walls, just the paths and driveway as it's so powerful

no need to use on walls , some threads on this site which say power washing cobblelock is a big No No , that it will ruin it ?

legend99

When I've down it, as mentioned above, I would repoint with sand. You'll blast loads of sand out anyway so it will be obvious. So you'll need to clean that up, there will be quite an amount, and you'll need to repoint with kiln dried sand then by brushing it into all the gaps between the blocks. Obviously needs to be dry to do this.

Stihl waters

Mad_maxx wrote: »

no need to use on walls , some threads on this site which say power washing cobblelock is a big No No , that it will ruin it ?

It has done nothing to mine on 15 years, as said above brunch some pointing sand in after

Mad_maxx

Stihl waters wrote: »

It has done nothing to mine on 15 years, as said above brunch some pointing sand in after

it had not crossed my mind at all that it might do harm until i looked up some old threats on the topic

il go ahead and hire the honda 3000 PSI , if the weather was good enough - dry enough , could you brush in the paving sand the following day or would you need to wait longer ?

Stihl waters

Mad_maxx wrote: »

it had not crossed my mind at all that it might do harm until i looked up some old threats on the topic

il go ahead and hire the honda 3000 PSI , if the weather was good enough - dry enough , could you brush in the paving sand the following day or would you need to wait longer ?

As long as the ground is dry you could crack on

Mad_maxx

Stihl waters wrote: »

As long as the ground is dry you could crack on

good, house is a hundred mils away so not easy do it a week later

legend99

Tomorrow and Sunday are supposed to be warm I think? After that it gets much cooler so maybe less drying? If you try to do it when wet it is very difficult. The sand will get wet and then sticks together. You want the kiln dried as the dryness means it "flows" far more easily and essentially as you brush it over the cracks it falls down into them and fills the space which is needed for stability and to reduce weeds etc. But they always fecking grow back to some extent. Lots of YouTube videos. And the other alternative that some people prefer is soft washing.

For what it's worth, I had a cobble lock drive put in two years ago and the last bit of advice the guy who did it for me was not to power wash it. Apart from having to put back in the sand, he said it destabilises the paving blocks and it's never the same after. He was a very experienced and well regarded tradesman. Washing powder, a soft brush and refilling the sand is as far as I go.

Mad_maxx

Deleted User wrote: »

For what it's worth, I had a cobble lock drive put in two years ago and the last bit of advice the guy who did it for me was not to power wash it. Apart from having to put back in the sand, he said it destabilises the paving blocks and it's never the same after. He was a very experienced and well regarded tradesman. Washing powder, a soft brush and refilling the sand is as far as I go.

Knew I'd heard it somewhere, take a long time to clean without a power washer though

Mad_maxx

Mad_maxx wrote: »

Knew I'd heard it somewhere, take a long time to clean without a power washer though

I do mine in a few hours. Sprinkle washing powder in the morning, mist it with the hose and then wash clean with soft brush in the afternoon. Kills the moss and the stones come up very clean. I'd avoid anything with too much bleach in it as it may remove the colour.

Mad_maxx

Deleted User wrote: »

I do mine in a few hours. Sprinkle washing powder in the morning, mist it with the hose and then wash clean with soft brush in the afternoon. Kills the moss and the stones come up very clean. I'd avoid anything with too much bleach in it as it may remove the colour.

do you dilute the washing powder into water and put on with a watering can or something ?

is it regular washing powder like for washing clothes ? , daz or something

spuddy4711

Use Biological powder if you’re hoping to kill moss, cheapest will do. Either sprinkle and water in, or

mix it in a watering can, hot water. If you want to avoid chemicals, a wire brush will shift the moss,

and remove less sand than power washing. Two kinds of fine sand available, for brushing in later,

one has a growth inhibitor, I found this was harder to apply, almost like a powder, and the moss

reappeared as usual.

Mad_maxx

spoke to a landscape gardener today who is doing some work for me in a few weeks time , hes someone whos opinion id value highly , he said power washing it wont do any harm, he also said the cleaning products aimed at cleaning they have in garden centres are no better than washing powder and if you do use them , you need to mix much stronger than it says on the tin