How to kill green stuff on exterior walls prior to painting?

Hi again,

On the painted exterior rendered walls of my house there are some areas that have become coated with a typical very fine layer green stuff, mainly where the wall is damp due to a leaking gutter which will be fixed shortly. The green stuff is extremely thin. What is a cheap, effective, easy way to kill or remove this, prior to painting with exterior emulsion?

Would household bleach work? It seems to work well on interior mildew.

Al

Reply to
AL_n
Loading thread data ...

Pressure washer.

Reply to
The Natural Philosopher

You'll need to get it off for the paint to stick properly. A tiny bit of copper powder in the paint prevents its recurrence. Tiny because the copper is toxic, and turns green or brown in time.

NT

Reply to
Tabby

Tabby wrote in news:f4896aff-fb84-46b3-af19- snipped-for-privacy@o20g2000yqk.googlegroups.com:

Thanks. Doesn't that discolour the paint, though?

Al

Reply to
AL_n

The Natural Philosopher wrote in news:ijqppf$bkr$ snipped-for-privacy@news.albasani.net:

I'll do that, thanks. I'd still like to make sure that every cell of green stuff is killed though, before I apply paint.

Al

Reply to
AL_n

formatting link

Reply to
The Medway Handyman

Reply to
Huge

--------------------------------------------------------------------------------------

Try brushing one part bleach to six parts water. Its what they use to wash off 'growers' on grave stones.

Reply to
john reeves

If you use too much it does. It really only needs teh tiniest amount.

NT

Reply to
Tabby

Nope. BENZALKONIUM CHLORIDE.

Reply to
The Medway Handyman

I painted over tons of it. It stays dead under paint. No light probably.

pressure wash then water based exterior paint. take at least a year for it to start growing again..

Reply to
The Natural Philosopher

"john reeves" wrote in news:ijrbck$7lv$ snipped-for-privacy@news.eternal-september.org:

Thankd=s for the tip. Bleach certainly seems to work well for mildew. Having said that, the last time I killed some inderior mildew with bleach, some other form of growth took over. It looked like white fluff! When I saw that, I thought "Ah, that stuff must LOVE alkalinity!! So I doused the wall with vinegar! No more white fluff, to date...

Al

Reply to
AL_n

"AL_n" wrote in news:Xns9E93B9C6AF8D1zzzzzz@130.133.4.11:

PS.. I tell a lie. I just had a look and the white fluff is back with a vengeance! I notice it is completely odourless, so perhaps it's not vegetable matter at all, but rather some kind of mineral crystalline growth.

Al

Reply to
AL_n

Google efflorescence.

Reply to
The Natural Philosopher

The Natural Philosopher wrote in news:ik00pp$7d8$2 @news.albasani.net:

That's it! Thanks...

Reply to
AL_n

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.