When I looked at the specifications for the room addition job 11 years ago, I thought I was seeing things. The architect had actually specified a whitewash finish! It made sense after you went to the jobsite to look at the original home. The house was built in the 1920's and looked like an English cottage. It looked to me as if it was painted white and was simply in need of a new paint job but what I was looking at was a magnificent whitewash finish that was about 35 years old.
One of the things that amazed me was the fact that the finish on the house was not peeling. There were bare brick in places and some places where you could barely see through to the brick below but that was intentional. The original painters had varied the thickness of the whitewash and actually left it off in places to simulate a faded or worn look. How clever of them! My challenge was to duplicate this old look on a new room addition. I'll cut to the chase. I did it and if you were to drive up to the jobsite today you could not tell the difference between old and new. It took a few experimental attempts, but my painters and I got the job done.
What is in It?
Whitewash formulas and recipes are quite different. Some reference all sorts of different ingredients but perhaps the most important one is lime (use hydrated lime). If you have worked with cement or brick mortar then you know why lime is a key ingredient. Lime is a powder that does something special once mixed with water. When you add water to lime a chemical reaction begins. Millions of tiny crystals start to grow. These crystals allow the lime or whitewash to tenaciously grab onto whatever it is applied to. It is not unlike the small briars that stick to your socks and pants when you walk through the woods.
There are other strange ingredients in different whitewash recipes. I can't tell you what they do or how they affect the final product since the whitewash I used only contained hydrated lime and salt.
Once you mix up whitewash you usually don't have to use it right away. In fact some of the recipes want you to let it sit overnight or for a day before you apply it. It is also a great idea to make sure the surface you are applying it to is clean and damp. The lime crystals will penetrate deeper into the wood or the masonry if it is slightly wet.
The whitewash usually goes on blotchy. It looks like it is not covering well. But wait till the next day! If you put on a normal coat as you would paint, it dries a brilliant white. The best thing to do is to experiment on small areas. See what you think about how white it turns out.
Whitewash doesn't have to be white. You can make it look dirty by adding charcoal dust. You can make it look yellow by adding dry shake pigments. There are all sorts of ways to color it. The key is to experiment! Mix small batches and carefully note the concentrations. Always let it dry for several days to see the final color.
You can buy the dry pigments at businesses that sell special products to concrete contractors. These are special places that will be listed in the Yellow Pages under Concrete - Supplies. They also sell all sorts of wonderful epoxies, sealers and other things that concrete contractors need.
Remember, the key to success with whitewash is experimentation. You want to try it on a test wall or some spot to get the feel and look of it. Wait till you see it!