Hard Coat Stucco

As a building material, hard coat stucco is a durable, attractive, and weather-resistant wall covering traditionally used as both an interior and exterior finish.

What Hard Coat Stucco is Best For

Hard Coat Stucco can be installed on any type of construction, on masonry buildings and on wood framed buildings, residential and commercial.
Hard Coat Stucco may be used for the following:

Exterior and interior cement plaster wall covering
Appearance
Durability

Hard Coat Stucco Components

Hard Coat Stucco is a multi-layered wall system that consists of the following components:

Lime
Portland cement
Sand
Fiberglass
Water

Types of Hard Coat Stucco

Traditional stucco – contains a mixture of lime, sand and water. It was traditionally used as both an interior and exterior finish applied in one or two thin layers directly over a solid masonry, brick or stone surface. The finish coat usually contained an integral color and was typically textured for appearance.
Modern stucco – contains a mixture of lime, Portland cement, sand, and water, but may also consist of a proprietary mix of additives including fibers and synthetic acrylics that add strength and flexibility.
Sculptural and architectural – Stucco has also been used as a sculptural and artistic material. Stucco relief was used in the architectural decoration schemes of many ancient cultures.

The most common type of hard coat stucco used in the United States is the modern stucco, known as a real cement based stucco.

Hard Coat Stucco Installation

Both, the traditional and modern application of stucco and lath occurs in three coats — the scratch coat, the brown coat and the finish coat.
The first step is to apply a water-resistive barrier, a material behind an exterior wall covering that is intended to resist liquid water that has penetrated behind the exterior covering from further intruding into the exterior hard coat stucco wall assembly.
Next, a metal lath needs to be applied, which consists of a metal wire and some other accessories, such as weep screed, corner aid and plaster stop attached with nails or screws to the structural framing.
The scratch coat is a base coat and the first one to go on the wall. It is applied with a hawk and trowel and a scratcher. The cement is spread evenly among the surface at a depth of about 3/8 of an inch thick.
The brown coat is applied after the scratch coat and is applied using the same techniques that were used on the scratch coat.
The final step in the process is the finish or top coat. This is applied with a hawk and trowel usually (depending on the finish) and can be customized a number of different ways using several different techniques.
The color of the stucco is either in the stucco itself or is applied with a finish coat that is applied over the stucco base.