Pressure washing

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Colin
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Joined: Fri Oct 10, 2008 12:37 pm
Location: Cornwall/Devon Border

Re: Pressure washing

Post by Colin » Tue Mar 16, 2010 8:22 pm

Painting over the Algae, dead or alive, means that it is between the surface and the paint therefore the paint ain't going to stick. If the Algae is still alive it will carry on growing - even under the paint, and the fungicide in the paint is only there to kill any fungal spores that just happen to land on the wet paint, its not strong enough to kill whats underneath.
I've done a few jobs where the previous painters couldn't be arsed to clean off the lichens, which carry on growing. With a nice protective "hat" of paint on, they are hard to scrape off. :angry:

Peterpainter
Posts: 156
Joined: Tue Jun 16, 2009 7:48 pm
Location: Cardiff

Re: Pressure washing

Post by Peterpainter » Tue Mar 16, 2010 9:06 pm

I have never painted over algae like i said i alway clean off algae with fungicidal wash/brush. just dont pressure wash the entire building. Only set up on my own last year and did two external render jobs one was so bad I had it blasted first. I guess I will be off to buy a pressure washer before/if the summer kicks in. Thanks.

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jerry3571
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Joined: Sun Feb 21, 2010 10:17 am

Re: Pressure washing

Post by jerry3571 » Wed Apr 21, 2010 8:27 am

I use a third bleach to water for algae and mould. I do pressure wash off but on Masonry it has been said that using a pressure washer almost injects water in to the substrate causing future problems. Also if Salts are not removed prior then the water can disolve and then be re-absorbed back in to the wall or bring out deeper salts.
I don't know :001_unsure:

Cheers Jerry

Peterpainter
Posts: 156
Joined: Tue Jun 16, 2009 7:48 pm
Location: Cardiff

Re: Pressure washing

Post by Peterpainter » Sat Apr 24, 2010 3:33 pm

The whole design of a cavity wall is that water can saturate and pass through the outer skin and run down the cavity/wall tie, so I dont think moisture can get trapped, unless it is a really old house cavity walls have been around for a hundred years now. I know masonry paint is breathable anyway, so as long as the surface is dry then the substrate can continue drying out after its painted.

Peterpainter
Posts: 156
Joined: Tue Jun 16, 2009 7:48 pm
Location: Cardiff

Re: Pressure washing

Post by Peterpainter » Mon Apr 26, 2010 9:15 pm

Some good in info on pressure washers if anyone is looking, especially the motors bit: http://www.diyfaq.org.uk/electrical/pre ... er_faq.htm

Squeen
Posts: 26
Joined: Tue May 22, 2012 7:52 pm

Re: Pressure washing

Post by Squeen » Thu Jun 28, 2012 4:34 am

Word of warning,we have had 3 karchrs ,every one has had serious faults, they are made for a very light domestic market.
Tired of all the hassle I bought a Kranzle, 2 years of heavy use still brilliant.

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