[Mike Halliday]

just been to price up a job for the cleaning of York stone pavers before they are laid into a kitchen, they are stacked in piles on the driveway.

below is a photo of them before they were taken up. as you can see they have a lots of lichen spots, the customer wants 100% removal of the black spots or he won't have them laid into his new kitchen, he has told me that to buy more reclaimed York stone would cost his a fortune so he wants to use the supply he has.

I think I could clean 80% of his pavers with a 100% result using hypo & powerwashing

but do you think with a strong mix of hypo I could get all the spots off? time is not an issue as we have arranged a day price and he just wants a great result so cost is not a problem

[Mike Halliday]

this a photo after he has cleaned them with his little karcher machine, I would assume I would remove a considerable amount more of the black spots before using the hypo

[chris scott]

Wet it...Bleach it...Wash it....Quats it.....Teflon it.
Just did one comes up superb!

[G O Cleaning]

Yes I think it will all come off using Hypo, why not take a sample way to clean for free, just to be on the safe side, then there can be no possible issues with the customer in regards to the end results 

[Mike Halliday]

Thanks for the replies, already done a test with the hypo, going back tomorrow to check on the result, didn't have a lot of time so soaked it then covered it with a  tarp to stop it drying out too quick.

How long will the hypo need to work?

[chris scott]

If i was feeling sarcastic....which people seem to think i am. I would use  shake and vax colour catcher..leave to dwell ....rhino horn powder and agitate with a clitax old scrubber  

[chris scott]

How long will the hypo need to work?

Depends on the strength of the mix and severity of soiling. There is no manual for it. Start as weak as poss and short dwell times till you get the desired results.

[Smudger]

Chris - for the ignorant (namely me  )

Hypo.?  What's that ??

And Teflon it - this does what ?

Cheers
Darran

[chris scott]

Sodium hypochlorite ...Bleach  
Teflon... A  breathable sealer prevents staining from fats ,spills etc (This instance spills within a kitchen environment) Commonly used to coat frying pans ..non stick,easy clean . Recently technology has allowed it to become saturated in water for easy application and the later ones have high sheer (wear) resistance .

[Smudger]

Cheers for that Chris!

Darran

[Mike Halliday]

Doing the job today, the test I did was acceptable although I did'nt remove 100% of the spots ( I might try a stronger mix today)

They really did'nt have an option as they are getting the floor laid on Monday. The way I see it is 50% the pavers won't have any lichen on so will clean up fine, on the other 50% if I remove 90% overall it is a 95% total removal and the can lay the spotty ones in positions that are less noticeable.

The hardest part of the day will be moving them around, they are stacked all over thier garden (& its a big garden)

[Jettaway]

What strength mix and dwell was you trying Mike?

[Darranvps]

DOFF it off!

[chris scott]

DOFF it off!

Stonehealth will not hire him the machine....don't you mean Therma-tech?

[Mike Halliday]

What strength mix and dwell was you trying Mike?

We did a patio in situ before they took it up, it took 3hrs to 98% remove the lichen this was with a 5-1 dilution we just kept it damp every 20-30mins

Hopefully this link will work, this photo is an example of the full patio and the clean section is the result we achieved over the full patio

https://www.dropbox.com/s/fp8cq0jyo7xinq8/2013-10-02%2011.46.35.jpg

[Kev Martin]

A Rotary Machine fitted with a soft to medium brush, pre wet than add a diluted high alkaline and some honing powder and the results are amazing.  Less dwell time, safer and less clean up same or better result.

Kev Martin
Tiling Logistics Ltd
Marblelife Ltd