Cleaning Painted Exterior Walls

[MikeyMike]

The walls of our new to us house are painted white, but are pretty grimey at present. I intend to repaint them in the summer but I'd like to give them a clean in the meantime. Beyond soapy water, what easily accessible products would do the job? We live out in the sticks so the grime tends to be general dirt and algae rather than exhaust pollutants that you may find in more built up areas, if that makes a difference.

Thanks

[finlo]

Comma truckwash, or even bleach and water.

[8-P]

I pressure washed mine, then scrubbed with caravan cleaner, then washed again

[trev540]

fungicidal wash available at decorators merchants is easiest, paint on and rinse off next day.

[Croutons]

trev540 said:

fungicidal wash available at decorators merchants is easiest, paint on and rinse off next day.

Or any diy chain, it's great, kills mould, so needs to be cleaned off, but defo worth it. If you do it now, you might sensibly do it again before you paint to ensure the surface is mould.free before painting over it, so maybe just jetwash for now, but do factor in the time to paint this stuff on, then get it off, before masonry painting (ie another day at least, as it has to dry then get washed off, which then needs to dry, before you paint).

[dickymint]

Another thumbs up for jet wash especially with a patio cleaning attachment.

[Murph7355]

Personally I'd avoid jet washing rendered/pointed surfaces...

[8-P]

Murph7355 said:

Personally I'd avoid jet washing rendered/pointed surfaces...

I would if they are old and look fragile, mine were 30 years old and no problem but then just like when using it on a car I would exercise some caution, you can take the paint of your car if you get too close at the wrong angle, I know, Ive done it!

[jeff m2]

Trisodium Phosphate usually just called TSP.

Good for cleaning paint and also very good for paint prep if used at stronger dilution.
It will remove any green or black mold and any oxidised paint leaving a ready to paint surface.

It has a very high PH....gloves advisable.
Needs rinsing off very well.

Should you get some on your hands...vinegar is good as a way to nuetralise.