It’s not easy to keep farm buildings looking neat. Painting isn’t always at the top of your list of things to do, and some sheds are so old that paint won’t stick to the crumbling plaster. Damp can also be a problem. Cladding walls with stone offers a permanent maintenance-free solution. Once you’ve mixed the cement, you need suitable stones, a trowel, a spirit level (for foundation, top line, and for plumb vertical face as well as corners and ends), a rubber mallet to tap the stones into place, and a splash brush.
When the cement is dry, clean the stones with a solution of swimming pool acid. Use just enough to cause a reaction on the stonework. Rough casting is another easy-to-do method that gives a nice finish. You use a hand-operated machine called a flicker, obtainable at hardware stores. It flicks a 50:50 mixture of cement and coarse sand evenly onto the wall, which becomes rock hard. The wall surface should be rough enough for the plaster to stick to.
For colour, ochre can be added to the mixture. Then there is an old ‘Karoo mud’ recipe, which is even cheaper and easier to apply. Mix together 10 wheelbarrows of whatever coarse sand is available for building in your area with a 25kg bag of builder’s lime. Mix well, at least a day before use, but three days is better. Then mix another 25kg bag of builder’s lime with a spade of cement and water.
The thinner the mix and the rougher the wall surface, the better. Over the years, you can build up the layers of wash and the wall will become more textured and stronger. This is a very cost-effective and natural-looking way of neatening up a building.