“Lime? What kinda lime? Whatcha gonna do with it?” I was sitting in a hardware store staring at a tower of dusty white bags. “You’re whitewashing your house, right?” The store owner grinned at me from beneath a large black moustache. “Erm, no. I’m building with it. I’m constructing a house without concrete, and I’m making the foundations with sacks full of limecrete.”
The store owner shook his head gravely. “Oh no no no,” he said. “You can’t build without cement, dear.”
Sigh. Unfortunately, this is still the opinion of far too many builders and architects, even those living in Turkey, a country visibly crammed with ancient buildings that have stood for thousands of years on foundations of lime.
After a long discussion in the hardware store, I finally managed to buy a tractor load of hydraulic lime. Four years later, I have one sack left. In the end I didn’t put it in the foundations at all, but I did use it plenty of other places. And the more I work with this wonderful white substance, the more I fall in love with it.
Lime is the predecessor of Portland cement, and is manufactured by heating limestone. It is can be purchased in two forms: Hydraulic lime, a powder which you need to mix with plenty of water and leave to soak for about two weeks until it looks like yoghurt, and slaked lime, a wet putty that has already gone through this process.
One thing to be aware of when using lime is that it’s caustic, so you need to wear gloves. But apart from that, it is everything that Portland cement isn’t: Namely, beautiful, breathable and best of all, carbon neutral.
1. To offset the greenhouse effect. Unlike Portland cement, which is currently one of the top two largest producers of CO2 (huge amounts are produced in the manufacturing process), lime is carbon neutral. It is produced at lower temperatures than Portland cement so uses only about 20% of the energy to manufacture. But best of all, lime reabsorbs the CO2 during its lifespan.
2. Earthplaster. For those building with mud in wet climates, lime is your best friend. Unlike Portland cement, lime breathes, so it doesn’t trap water vapour. When added to earth plasters, lime allows the damp to escape from the walls fast, preventing rising damp, mold and unstable plasters.
3. Lime wash. Lime wash has been used as a paint for centuries. Nowadays you can also colour the wash with natural pigments. The beauty of using lime on walls is that it’s non-toxic, allows your walls to breathe and creates magical interiors. It also repels bugs and prevents mold.
Here’s how to make a simple lime wash:
• 3 litres of slaked lime
• 200ml of white glue or salt (this helps fix the lime)
• natural colour (if desired)
• Water to thin
Mix all ingredients well until a smooth milky wash is created.
4. Pesticide and insect repellent. I can personally attest that a lime wash deters all manner of insects. Before I applied it to my mud plaster, mining bees were carving holes out of my walls. I’m happy to say they never returned post lime wash. Lime takes care of fire ants, wood ants, mites, aphids, flea beetles, and even mosquitos according to some sources. Lime wash can be applied to chicken coops, sheds, or sprayed on your garden to keep your plants bug free.
5. Putty If you drain off the excess water, slaked lime is putty-like in texture. You can then use it to fill in gouges in your plaster or smooth over cracks.
6. Limecrete Limecrete can be bought in slabs, or made and poured. Hydraulic lime is mixed with sand (and sometimes pozzolans) to create a durable surface. Limecrete can be used for floors, foundations and as a wall plaster, and is often preferred to Portland cement because it is breathable and reduces interior humidity.
7. Hempcrete Hempcrete is the natural building material of the moment. By mixing hemp, lime, sand and water together and allowing it to set in molds, a sturdy block is formed. These blocks can be used for wall construction. Hempcrete has also been used to create floors.
8. Fungicide and Disinfectant Lime is antifungal and a mild disinfectant. It prevents mold growing and is therefore perfect for walls that see damp or any area prone to bacteria.
9. Food preservation When I first heard a friend of mine saying she was going to dry eggplants with hydraulic lime to make eggplant jam, I was doubtful. “You taste it,” I said. ”I’ll stand by to call the ambulance.” In fact, the art of dehydrating food using lime is practiced in many countries, and often makes the food more delicious in the process.
One last word on lime: It’s very inexpensive.
Atulya K Bingham is an author and sustainable building addict. She lives semi off-grid in Turkey in her beloved earthbag house. Her days are spent growing her own food, experimenting with natural building techniques, and writing. For a limited time you can download her new ebook, Mud Mountain, The Secret Diary of an Accidental Off-Gridder for free! Read all of Atulya's MOTHER EARTH NEWS posts here.
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