Old fashioned 'White wash'

astrologic

I have an unsightly, concrete garage wall which seems to be suffering from mold, moss and mildew, from years of rain. I want to know the best way of covering up this wall and I remember my dad used 'white wash', as it was called in the 60s and 70s, to cover up our yard wall when I was little. It did an amazing job and seemed to withstand the rain brilliantly. Unfortunately, he passed a few years ago and nobody seems to remember what white wash was made of. I've tried looking in DIY stores and google, but can't find any reference to this product. Does anybody know of such a thing and if so, how do I make it? If it's too ancient a thing, does anybody have any solutions to this problem? I will be grateful for any and every piece of advice anyone can give. Thank you

MikeJXE

Here is a link to how to make white wash 

https://www.wikihow.com/Make-Whitewash

FreeBear

Whitewash - Otherwise known as limewash in some areas. Dead easy to make, and very cheap.

Some builders merchants stock Lime Putty. If you can not source any locally, grab a bag of hydrated lime, and mix it up in a big tub of water (an 80l bin is about the right size). Leave for 3-6 months for it to age in a frost free location. 

With either lime putty, or your hydrated lime, pour off the clear water and scoop out a good sized dollop. Mix with water to the consistency of single cream. With a stiff masonry paint brush, slap it on the wall in thin coats. Leave to dry, and apply a second thin coat. As it dries, the surface will be powdery,  so avoid rubbing it. After a few weeks, it will harden up and leave you with a tough finish.

If desired, you can mix pigments in (no more than 10%), but do be aware that some colours are not suitable - Blue & green are not generally stable in lime and will fade. Once the wash has dried blue & green stabilse. Black is another colour that can not be achieved - You need a lot of pigment (waaay more than 10%), and the best you'll get is a dark grey.

In use, you will need to stir the mix regularly as the lime has a tendency to sink to the bottom of the can.

After you've scooped out a dollop from your main bucket, make sure there is an inch or two of water covering the putty before putting the lid back on. You can return the limewash back to the main bucket when you're done.

You can purchase ready made limewash from the likes of Farrow & Ball - Darned expensive though. £63 for a 5l can. Compare that to ~£18 for a 20kG tub of lime putty that will make 100l or more of limewash... Lime putty can also be used to make mortars & plasters, so has plenty of uses around a house (and yes, I do have some tubs).

Further instructions on using limewash -> https://www.limebase.co.uk/product/limewash-16l-53-colours/

twopenny

Do you have any National Trust villages near you or one of their maintenance yards?

They aren't likely to be as generous as to let you have some but they may have some tips and tricks on lime wash. They use it on all the cottages in the SW.

I did this when I needed to locate old roof tiles and they were able to point me in the right direction to find them

astrologic

Thanks guys, that's really helpful!

FreeBear

And you can also add 1% or so of linseed oil to the mix for a bit more weatherproofing. But if you do that, don't tip the remains back in to big tub.