Sustainable Building Program and Courses at The Endeavour Centre

Red wall almost finished

Natural clay finish plasters add an unparalleled beauty to any home, and it was exciting to apply these plasters to Canada’s Greenest Home this weekend.

These skim coat plasters can be applied over any wall surface. In this project, we used them over clay base coat plasters and over drywall.

The plasters are mixed on site using widely available and affordable materials. Clay, sand, calcium carbonate, pigment, flour paste and water are mixed together and applied to the wall by trowel in a single, thin coat (~1/8 inch).

Our typical formula is 10 parts clay, 4 parts sifted sand, 1 part calcium carbonate, 1 part flour paste (a natural glue/hardener) and ~3.5 parts water. Natural pigments are added to this mix by weight, based on trial samples made in advance. As with baking, the dry ingredients are mixed together and then added into the water, flour paster and pigment that have been blended.

The clay in this case is Tile 6 Kaolin, from a pottery supply store. We’ve used other kaolins and ball clays with similar results. Calcium carbonate is finely ground limestone, from Omya in Perth, Ontario. Flour paste is cooked by boiling 4 parts water and adding a mixture of 2 parts cold water and 1 part flour and boiling until thick. Our natural pigments come from Kama Pigments.

Helping us with the mixing and application was our good friend Mike Henry, a plasterer with Camel’s Back Construction. His attention to detail helps bring out the best in the clay plaster.

There is nothing like the depth, richness of colour, sound attenuation and warmth of a natural clay finish plaster!

January 20, 2013 **Workshop Cancelled**

We will attempt to reschedule this workshop in March

Workshop Instructor(s): Anna Wolfson
Anna Wolfson Design

Workshop Description

Beautiful accent walls can be created using natural materials like clay, sand, pigment and mica, and Anna Wolfson is a master of teasing out the best possible results from the natural finishes palette.

In this workshop, Anna will show participants how to use a number of widely available, natural and healthy materials to create a wealth of different finishes. Whether you are remodelling a room or building a whole new house, you will be able to apply Anna’s techniques to your home with amazing results.

If you have ever wanted to bring the warmth, beauty and unmatched feel of natural materials into your home, this is the workshop for you!

Entry Requirements

Open to all

Fee

$125

Maximum class size: 12

Clay Plaster Workshop group photo

Endeavour’s first clay finish plasters workshop achieved its goal: to infect more people with the urge to cover walls with clay! The workshop participants spent a full day learning about mixes and application techniques and playing with a wide range of natural colours. Then we spent a day plastering a room in a home to get a “real world” sense of preparing, applying and detailing an actual home project.

Day one started in our new shop space, where we are able to spread out all the materials and equipment needed for a day of plastering fun. Materials, mix ratios, surface preparation, pigments and techniques were all covered so the playing could start in earnest!

Colour samples made using natural pigments

At the mixing station

We concentrated on making very small samples to begin, allowing people to see how the pigments work and try out some troweling on very small pieces of drywall.

At the pigment centre, trying to choose!

The next step was to mix a larger batch of the chosen colour and apply it to a sample board on the wall. Each person had multiple sample boards to experiment with.

Applying clay plaster on a sample board

The remainder of the day was spent working on sample boards, trying out different colours and different troweling techniques.

Mixing clay finish plaster

The next task was to learn how to calculate the mix formula to be able to cover larger areas. We mixed the plaster for the next day’s room, using the square footage of the room and a formula for knowing how much material to mix. Since it is preferable to mix clay plasters the day before using them, this is how we ended the day on Saturday.

On Sunday, we showed up to prepare and plaster a room in a home. After masking and protecting the floor, the plastering began. Working on a real room is helpful, as dealing with corners, trim and in this case a tricky chimney section really helps develop the skills necessary to undertake one’s own projects.

Clay plastering a room

Working in a real room also helps to develop a sense of the timing required to keep wet edges, deal with corners and know how long a job might take. Our amazing crew had this room done in just a few hours!

Jen stencilling clay plaster

Then it was back to the shop for a bit more fun. We looked at stencilling clay plaster (using a finer mix) over our samples. We also played with texturing on top of existing samples and techniques like scrafito (scratching away one coat to reveal the colour coat beneath) and carving (removing parts of one layer to reveal the layer beneath).

Stencilling clay plaster

By far, the stencilling was the most popular technique. It’s quick and easy and the results look great!

A stencilled clay plaster design

After the workshop, we went back to take some photos of the finished room. The owners were thrilled with the results. There’s nothing like clay plaster to make a room beautiful, warm and inviting!

Finished clay plaster bedroom

Our thanks to all the participants who came out for this workshop! We had a great time, and look forward to offering this workshop again!