Red marks on through render walls.

I have a lot of inquiries for removing red marks from rendered walls. Most people have no idea what it is, how it got there and most importantly how to get rid of it! This blog post will hopefully answer some of the questions you may have…

What is it?

We have heard all sorts. Some people have been told it from silicone in the wall that is bleeding … some say it is something dripping from the roof.
What it actually is is algae. This algae needs to not only be removed from the surface, but most importantly it needs to be killed. This is why pressure washing will not be an effective solution to the problem.

How is is to be cleaned?

Is pressure washing the answer?

Some people will choose to pressure wash the render to remove the red marks. This is a sure way to damage the walls. Through coloured render (common brands are: K Rend, Monocouche, Weber, etc. ) is a soft surface that need to be treated as such. We have seen some of the results from pressure washing through coloured render achieved by other cleaning companies and some of the results are terrible. Rather than killing the algae, using high pressure takes the top layer of the render away. As you can imaging, this is a bad way to clean this type of surface! This leaves etching on the through coloured render and damages the wall being ‘cleaned’.

Red algae marks on k render walls

The best way to clean it

The algae needs to be killed. How do we do this? We have trialed many, many chemicals to work out the best way of cleaning through coloured render. Whenever a new product is released we will give it a go, but we are confident we have found the best way of cleaning through render.
Under low pressure we apply a mixture of chemicals that are softly brushed onto the surface and left to do their magic. Red algae is the worst type of algae to remove. It takes longer than green  and black algae, but is can be removed! We find that red algae may take several applications of our chemical mix to effectively remove it completely.
As you can see from our after photo on the right the original colour can be brought back to the building.

Would you like to have the red algae removed from your property?

We cover South Wales and the South West of England for render cleaning.
We have many examples on our website  ….  here is a link  …  Render Cleaning
There are several companies throughout the UK offering a first class cleaning service of rendered surfaces, that understand the right way to go about cleaning K render, monocouche render, sto render, etc. If your property is too far away from us to be able to travel to we are happy to recommend one of our contacts close to you.

How to contact us

Freephone: 0800 6101 275
Mobile: 07940 125 275
Website: www.leeksons.com
Red algae marks on k render walls