Create Test Mixtures Before Rendering a Wall with Adobe Plaster, with Video



Sand and clay mixture tests by Tom Keeling. Fazenda Tomati Portugal Permaculture Design Certificate 2019

In the video below, I cover some basic tests you can do to analyse your earth for rendering. It is important to do as many tests as you can before applying an earthen finish. For me the main reason for doing this at every job is that the earth is always going to be a little bit different, even if in this case the earth was mined from the same site as a previous job.

Why We Do Render Tests for Earthen Walls

We knew from before that this particular mine gave earth with a very nice percentage of clay to sand (minute 25:75 in the video), which was ideal to work with, but even so we still carried out the basic tests to see how the mixtures fared in our particular conditions.

Another good reason for doing tests in this site in particular is that we were working on to cement block walls and even a modern paint in one of the spaces. For this reason it was very important to see whether the render would even stick, especially in the case of the smooth-rendered, modern white-painted walls.

So as with any job we made our tests, changing the quantity of sand to clay in each case. We had four different surfaces to work on to and we made four different mixtures. On past jobs I have done up to 12 tests and depending on the materials you are using and the parameters you want to test. In this case, we had two ingredients, sand and earth, so we didn't have to do quite so many tests. When testing a render on an exterior wall with four ingredients, where colour, texture as well as water resistance was important, this is where we did 12 tests.

Subscribe Today - Pay Now & Save 64% Off the Cover Price

50 Years of Money-Saving Tips!

Mother Earth NewsAt MOTHER EARTH NEWS for 50 years and counting, we are dedicated to conserving our planet's natural resources while helping you conserve your financial resources. You'll find tips for slashing heating bills, growing fresh, natural produce at home, and more. That's why we want you to save money and trees by subscribing through our earth-friendly automatic renewal savings plan. By paying with a credit card, you save an additional $5 and get 6 issues of MOTHER EARTH NEWS for only $12.95 (USA only).

You may also use the Bill Me option and pay $17.95 for 6 issues.

Canadian Subscribers - Click Here
International Subscribers - Click Here
Canadian subscriptions: 1 year (includes postage & GST).

Facebook Pinterest Instagram YouTube Twitter flipboard

Free Product Information Classifieds Newsletters