Stained slate

[vfrdave]

Hi folks

Grateful for some help again.

It seems that when my k-rend chimneys were scraped that it went everywhere.  As a result my slates seems to be tarnished with the colour and lots of k-rend trapped all over the place. The hose seems to dislodge the k-rend granules but doesn't clean the slate.

How do I get these clean?

[nod]

13 minutes ago, vfrdave said:

Hi folks

Grateful for some help again.

It seems that when my k-rend chimneys were scraped that it went everywhere.  As a result my slates seems to be tarnished with the colour and lots of k-rend trapped all over the place. The hose seems to dislodge the k-rend granules but doesn't clean the slate.

How do I get these clean?

Oach  They should have covered the slate

The only way to clean it is brick acid on a sponge Carefully clean each slate being careful not to get any on the render When you hose down keep the hose directed onto the render for ten minutes 

The renderers will tell you it will weather off It won’t But the bits under the slates will

 

Hope this helps 

[vfrdave]

I think they covered some of it but the wind didn't help. The bits under the slate wash out with the hose. @nod should I use pure brick acid? Should I do this sooner rather than later? Would prefer to wait until guttering is on.

[Ferdinand]

How do you make sure it is all ou5 pre-cleaning?

 

What will stop it staining again?

 

F

[vfrdave]

11 minutes ago, Ferdinand said:

How do you make sure it is all ou5 pre-cleaning?

 

What will stop it staining again?

 

F

I can only assume that the granules that are left are hard enough to now not stain if they get wet.

[Ferdinand]

1 minute ago, vfrdave said:

I can only assume that the granules that are left are hard enough to now not stain if they get wet.

 

Perhaps a gentle power wash or hose finger across the face of the roof first?

Edited August 11, 2018 by Ferdinand

[vfrdave]

14 minutes ago, Ferdinand said:

 

Perhaps a gentle power wash or hose finger across the face of the roof first?

I suspect this will be a 2 stage process. Hose roof from top down to remove as much of the granulated render from under tiles. Then, acid and rinse down.

[Declan52]

I wouldn't put it on neat. Would go 50/50 with water and see how that goes. If that doesn't shift it then increase the acid dose bit by bit.

I would put a few planks with some polythene nailed to them lying up the wall to catch the run of. Don't want the nice wall getting splashed with acid.

[nod]

6 hours ago, vfrdave said:

I think they covered some of it but the wind didn't help. The bits under the slate wash out with the hose. @nod should I use pure brick acid? Should I do this sooner rather than later? Would prefer to wait until guttering is on.

It’s not easy

They could have cleaned it with water had they done it right away

We get this problem in winter when it rains while we are rubing the render down 

Brick acid sounds harsh But a small amount on a sponge will move it Tge longer it’s on the harder it is to shift Don’t forget to wear a rubber glove

 Another option is grout remover Less harsh 

[vfrdave]

37 minutes ago, nod said:

We get this problem in winter when it rains while we are rubing the render down 

I think that is what happened to them been largely dry and a surprise shower caught them out.