Underspray
A certain amount of plaster will inevitably dribble out of the sprayer and fall to the floor. As long as the floor is clean and the plaster uncontaminated, it can be pushed with a trowel to the wall, then pushed up the base of the wall to cover the bottom 6 to 8 inches.Plaster, p3
Plaster Application
Mix the plaster according to the manufacturer's recommendations. For the scratch coat, as earlier stated, we used a 1:2 ratio of lime to course, sharp, well graded sand, and mixed with enough water to make the plaster workable (not so dry it crumbles, or so wet it becomes a slurry). The plaster turned in the mixer for as long as 45 minutes per batch, allowing the lime to adequately hydrate. Once ready, it was dumped into a wheelbarrow and moved to the door of the structure, where it was easily accessible from inside.
Shooting lime plaster with a Tirolessa sprayer.
With the walls damp and the plaster mixed, spraying commenced. Though each batch of plaster took about 45 minutes to mix, it required only about ten minutes to apply using the Tirolessa sprayer. Once the plaster has been sprayed on to the walls, it may be troweled smooth then scarified, or simply left as is, with the sprayer delivering a sufficiently rough coat to which the brown coat can adhere (more information on the Tirolessa sprayer is available on the Tools page of the Details section). Two of us plastered an area of about 500 square feet - the interior of the structure - in the course of approximately 8 hours.