Weber monocouche staining

man of kent

New Member
The front of my house at ground floor level has been re-rendered due to cracks brought about by replacement windows.
The rendering is Weber Monocouche (chalk colour) which is rough in texture. Previously the rendering was smooth and painted white.

Above is wooden cladding that was sadolin stained about ten years ago. Every time it rains, the new rendering stains incredibly badly. Due to the bad weather I'm washing it down with bleach based Hg mould remover or similar at least once a week. The whole point of having this rendering was to have a maintenance free wall. Yes I know I should have thought this through better but it simply didn't occur to me that after 10 years the cladding would do this. It never stained the previous rendering which I had painted with white sandtex.

The plasterer suggested sealing the new rendering with 'weberend protect', which is a strong hydrophobic coating. In theory any stained water would repel off the surface. Given the roughness of the render, I'm a bit dubious as to how effective it would be. However, if I tried it and it didn't work, would there be difficulty painting over it? Or would it be better just to bite the bullet and go straight to painting it with Sandtex Masonry paint and if so which particular product type? (and would I need to prime it first given this new rendering appears quite porous?)

Honestly, I'm surprised that anyone would use this monocouche stuff, given it is also prone to algae staining. I should have kept to traditional smooth cement rendering. The plasterer looked at me strangely when I asked if it could be painted and said to me that the whole point of coloured ' weber monocouche' (mine is chalk colour) was that it DIDN'T need to be painted!!!

Any advice appreciated.
 

Tom81

Well-Known Member
The front of my house at ground floor level has been re-rendered due to cracks brought about by replacement windows.
The rendering is Weber Monocouche (chalk colour) which is rough in texture. Previously the rendering was smooth and painted white.

Above is wooden cladding that was sadolin stained about ten years ago. Every time it rains, the new rendering stains incredibly badly. Due to the bad weather I'm washing it down with bleach based Hg mould remover or similar at least once a week. The whole point of having this rendering was to have a maintenance free wall. Yes I know I should have thought this through better but it simply didn't occur to me that after 10 years the cladding would do this. It never stained the previous rendering which I had painted with white sandtex.

The plasterer suggested sealing the new rendering with 'weberend protect', which is a strong hydrophobic coating. In theory any stained water would repel off the surface. Given the roughness of the render, I'm a bit dubious as to how effective it would be. However, if I tried it and it didn't work, would there be difficulty painting over it? Or would it be better just to bite the bullet and go straight to painting it with Sandtex Masonry paint and if so which particular product type? (and would I need to prime it first given this new rendering appears quite porous?)

Honestly, I'm surprised that anyone would use this monocouche stuff, given it is also prone to algae staining. I should have kept to traditional smooth cement rendering. The plasterer looked at me strangely when I asked if it could be painted and said to me that the whole point of coloured ' weber monocouche' (mine is chalk colour) was that it DIDN'T need to be painted!!!

Any advice appreciated.
mono is s**t and the sealing products need to be redone, there's no such thing as maintenance free render, you could have it topped off with silicone thincoat a lot more durable and stain resistant, Pliolite paint is a good masonry paint it's used on lighthouse's

 

Vincey

Private Member
Use the Weber protect then jobs a good one not all mono stains only some imo that’s mainly due to the surrounding areas if you drive and look around outside now you will see silicone and paints and house bricks are stained due to the environment here’s a house I looked at the other week even the bricks are stained green and another I looked at today the paint is stained
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man of kent

New Member
The staining occurs everytime it rains! I'm concerned that if I seal it with weber protect or similar, that it might make it difficult to paint afterwards if the staining still happens after a while.
Someone has also recommended Dulux Weathershield which would probably not stain. Anyone got a view on this product. Thanks
 

Tom81

Well-Known Member
The staining occurs everytime it rains! I'm concerned that if I seal it with weber protect or similar, that it might make it difficult to paint afterwards if the staining still happens after a while.
Someone has also recommended Dulux Weathershield which would probably not stain. Anyone got a view on this product. Thanks
DIY product!!
 
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