Clay Plasters

Instructors: Tim Rieth, Andy Burt and Kelly Cutchin

Course Description: In this workshop participants will learn the basics of mixing and applying clay plasters to walls, and how to determine the right plaster for your situation and needs. Clay plasters are most commonly used as a finish coat for cob or strawbale buildings, but also can be applied as a beautiful finish on any pre-existing wall.

Topics:

•  Breathability

•  Finding the right recipe for your substrate

•  Water resistance

•  Crack prevention where different materials meet

•  Mixing techniques

•  Site set-up

Required reading: None

What to bring:
Hawk and plaster trowel (4x10" recommended) we will supply trowels if needed

Eye protection (goggles)

What to wear:
Work clothes

Course Schedule

Day 1

•  Welcome and orientation to Yestermorrow

•  Introduction to the course and brief bio of instructors

•  History of wall finishes and the advent of plasters

•  The basic chemistry of plaster, why it sets vs. the evaporation of joint compound

•  Introduction to materials, demonstrations: plaster setting up, workability of setting materials

•  Lunch

•  Mixing of batches and troweling plaster onto sample wall board and wire mesh substrates, creating hybrids of both substrates

•  Identifying common preparation issues

•  Using mesh tape

•  Hand mixed batches and drill mixed batches

•  Creating various textures

•  The importance of your hands and fingers in corner and detail finishing

•  Joining old plaster walls to new work

•  Troweling tips and techniques

Day 2

•  Continuing the work from previous day

•  Inside and outside corners, techniques and options

•  Creating radii and irregular shapes, both hand-formed and patterns

•  Emergent architectural elements and finishing around trim

•  Using plaster on cement based substrates i.e. block or wonderboard

•  Using paints and pigments to color plaster

•  Students will pick some wall space in the new Yestermorrow dorm facility to finish plaster an area that they can sign f they like, ultimate goal to finish over all exposed block in the dorm areas.

•  Lunch in there somewhere.