Possible efflorescence?

gadget88

I got some slabs cut but left with white marks that were not there. Swapped one over from my back garden. Is it efflorescence not keen to jet wash these how long would weathering take to remove the white off the slab? Can anybody confirm if it’s efflorescence? There’s also some green from the garden trees at back will this wash out? The one at side went white just from cutting the other slab? ?

-taff

it isn't effloresence. You probbly rubbed it or steadied it there when cutting, did you kneel on it? and rubbed off some of the dirt. Or it's dust.

gadget88

-taff said:

it isn't effloresence. You probbly rubbed it or steadied it there when cutting, did you kneel on it? and rubbed off some of the dirt. Or it's dust.

It was a workman who done it so I wasn’t able to check. Could be dust but it was done two days ago. The long slab next to it is original and has white on it too? I think they used some sort of saw for it. Whats chances of it cleaning up?

gadget88

This was it right after the cut. I washed a cup of water on it. 

Keep_pedalling

The light colour is the natural colour the darker colour is a build up of dirt and lichens. Over time the light coloured bit will go the same way.

gadget88

Yes so the white cuts maybe dust as the slab was not white before the cut. How long would it take for white to vanish years or would it go within six months? 

Mr.Generous

Pressure wash the lot and you'll never notice.

gadget88

Mr.Generous said:

Pressure wash the lot and you'll never notice.

Yes only issue is I have a shared slab open plan half and half so it won’t match. Half would be done so would look newer. 

twopenny

Then let the other sharer do their half if they wish.

The more I see the more I realise that it's general not cleaning, just whatever the rain brings down, that has the colour and where it's been touched or worn is the natural one.

The step is the same. It's just an accumulation.

Pressure wash or use a wet and forget chemical which will keep them clean for the best part of a year or more.

gadget88

twopenny said:

Then let the other sharer do their half if they wish.

The more I see the more I realise that it's general not cleaning, just whatever the rain brings down, that has the colour and where it's been touched or worn is the natural one.

The step is the same. It's just an accumulation.

Pressure wash or use a wet and forget chemical which will keep them clean for the best part of a year or more.

Yes I mean I am undecided whether to try anything else or let it weather in but not sure how long until the white goes? A new driveway costs around 3 grand. Any new slabs or power washing won’t match up. 

ArbitraryRandom

Why not talk to whoever owns the other half and say you're thinking of pressure washing - do they mind if you do their side at the same time as otherwise it'll bother you... as long as you're not asking them to chip into the cost I don't see why they'd say no.