Anti damp paint?

[Zinxie]

Anyone used it? I was thinking might be a good idea to use it in the outside loo which needs repainting.

I have used it a lot. However an outside loo is a damp place and if you don't have any heating in there, it is never going to dry out. It is subject to a lot of moisture due to it being out side.
I would paint it with oil based paint on top of the damp proof paint.
Give the walls a good wash with some anti fungal wash first.
It will liook Ok for a bit, but eventually due to its location mould spores will be back.
Use Dettol mould and mildew remover to get it nice and clean looking again.

I would be happier with a breathing, porous paint that will enable the wall to dry out.

What led you to want an "anti-damp" paint?

I just saw it and thought it sounded a sensible precaution, pigletJohn. yet at the same time it seems counter intuitive if it prevents brick ventilation. So I wondered about it!

The outside loo has no heating and isn't mouldy. Currently it is old plaster which looks to have had something on it a long time ago, possibly whitewash or lime.

Thankyou hole , I've never painted walls with oil based paint. The anti fungal wash is a good idea. D'you think vinegar would do the trick?

I get mould spores or miss spores on the painted fence and fate, which I wash off with vinegar water and it seems to work, at least, I tend to only do it annually and it looks ok.

*moss, not miss.

Non breathing paint on lime plaster is a recipe for disaster!

Thank goodness I asked here, then! Thankyou! What would happen?!

Well, basically the wall would un-plaster it's self smartish. Not ideal.

The opposite of ideal, in fact.

Indeed

Lime wash would be best - non buggered with lime plaster is a real boon in an outside loo. It's why it's not damp.

It was the worse thing we did to our bathroom - instead of having mould we could wash off the water stayed on the walls and the paint crumbled off

Excellent, Lettuce, Thankyou for chiming in. I'm so glad I started this thread!!

andcake was that the anti damp paint that crumbled your walls?

Mmm. PigletJohn may yet chime back in and I'd take his advice over mine if they differ.

Good luck in any case.

I have seen old WCs and sculleries that have lime plaster, they were originally treated with whitewash or distemper.

I would use Dulux Trade Supermatt. It is a non-vinyl porous paint most often used for new, damp plaster as it allows it to breathe and dry out. Sadly it is not as durable as modern paints.

I don't like making distemper as it smells unpleasantly of boiled-up dead horses' feet.

There may be some specialist fancy paint peddled by people who supply old listed buildings. You could make up a limewash but IME it flakes off and is even more arduous to mix up than distemper.

There is special mortar paint for bricks as well. The wall will not dry out unless it has a damp proof course.
You need to get all loose paint off before you paint anything. If you paint on top of loose paint it will just throw itself off. A wire brush would be handy.

You can get a plaster mix that you put on with a roller. It is pretty hideous stuff but I have applied it to hide cracks. I just rolled it into small peaks.
However everything will go mouldy eventually in an outside loo. The bricks will be old as well. So they might be porous with shot mortar.

in all houses, but old ones particularly, porous surfaces and ventilation are key to dealing with damp.

If water evaporates from the walls, and the moist air is ventilated away, faster than water is added to them by leaks, rain or from the ground, the wall will be dry(ish).

If water is prevented from evaporating, or is not ventilated away, so it is lost slower than it is added, the walls will be damp(ish).

So I'm very keen on "breathing" surfaces and ventilation. Lime mortar, soft bricks, and lime plaster are all porous materials that will allow moisture to evaporate into the air.

If you have electricity in the WC, you can add a tubular heater to protect the plumbing from frost.