[Darranvps]

Hi
The pictures below show a wall which we tried to clean this morning. We used the following, 1st we tried pressure washing with water, then we applied ubic 2000 left to soak and then rinsed off, then we tried Amtech Wall Cleaner and rinsed that off. We then tried pure water through a waterfed pole.

We managed to remove by pressure washing the green mould/Algae on the surface but it left a green stain behind it.

Any help/advice on what chemical to apply would be appreciated.

Is there anything that can remove this stain as we used up to 200 BAR with no results.

[Matt Gibson]

what is the surface made of? is it rendered?

[Darranvps]

Hard to say, but I would think it is some kind of waterproof mineral plaster. When you knock on it it sounds hollow and I would suspect that their is a fibran type insulation underneath covered by a net and then the mineral plaster is applied. Other than that I don't know, nor do the building owners.

[H S and Son]

Paint.

Simples.

 

[Alex Gardiner]

I would personally use 'Hypochlorite'.

Have to clear the area first and wear protective gear - then rinse ground area off afterwards. You would also need appropriate Risk Assessments and COSSH Assessments in place.

[Matt Gibson]

...Thinks Matt's onto something....

[Darranvps]

Paint.

Simples.

 

Hi - I don't really think it is paint - more like a coloured plaster?
I have a property abroad and it was insulated the same way, no paint was applied just a coloured plaster.

[Darranvps]

I would personally use 'Hypochlorite'.

Have to clear the area first and wear protective gear - then rinse ground area off afterwards. You would also need appropriate Risk Assessments and COSSH Assessments in place.

Thanks Alex, I will take a look into it if nothing else comes up.

[mci services]

I think Matt meant paint it

[Ace Windows]

I use Granocryl (made by the Leyland paint company) on green algae etc. It does a really good job.
I apply it through a backpack and WFP brush. If you brush it onto the surface and leave it for 30 mins or so before you wash it off it works a treat.
I have only once had to retreat an area to remove all the green. It kills the growth at the roots and the surface stays clean for ages.
If you can't find any but would like to try it I can post some to you. It costs £3.19 for a bottle that makes 5 litres of solution. Not sure how much post would be though.

DJ

Not sure how to post a pic of the product on here but can email one to you if you want!

[jaespray]

hi rhino man     if its that porus very fine sand textured stuff     i would be very reluctant to put water under pressure on it   for a start you dont know if its been put on right   it looks like its been caused by insufficent over hang or drip sill     if it is that textured stuff you will have to wash every possible angle of the texture     the root of the algae i dout you will shift
regards john

[Griffus]

Looks like Render so painting probably best option.

http://www.sandtex.co.uk/

[Richy L]

Bleach scrubbed on with a hard brush.

But ideally it needs to be repainted.

[JSMC]

so what was use din the end and how did you apply it?

[JSMC]

so how was it applied and mixed etc ? did you wfp it off or pressure wash?

[awcs]

Dulux, it's the only way. That sort of rendering is slightly porus and is applied already coloured