Finish Coatings Type MD & PM EIFS

Finish Coatings Type MD & PM Descriptions

A decorative textured finish is applied over the base coats. This finish coat is integrally colored and formulated to resist the elements. The base coat and not the finish coat is the waterproofing layer of the lamina.

The finish product for EIFS is the last step in the process of completing the system. Interestingly enough most finish products are interchangeable between both PB and PM systems. The finish is a trowelable and sometimes sprayable, high build material with integral color and texture. The texture comes from various sizes of aggregates and the texture is achieved by the way one works these aggregates with a specific texturing technique. The minimum thickness of a finish is normally determined by the size of its largest aggregate.

Finishing is normally a two step technique:

Step one – When troweling, the material is applied with slight arm pressure causing the trowel to ride over the aggregate and therefore applying the finish to its proper thickness.

Step two – Produce the texture with a float or other type of tool.

 

Special Finishes

Most manufacturer’s make a variety of special finish products – some with additional enhancements and different benefits.

Some examples of different finish names and enhancements:

• Acrylic Finishes
• Siliconized Finishes
• Elastomeric Finishes

Then there are a variety of specialized finish products which are designed to give a variety of different looks. Some are designed to look like marble or granite. Others have properties that allow them to have a high build textured look. The high build finishes can be textured in countless ways and even can be made to look like heavy adobe. By far the most prevalent of the finish products we see today will consist of sand textured and swirl textured finishes.

 

Important Characteristics of EIFS Finishes

The EIFS finishes are:

• 1. Weather Repellent
  2. Vapor Permeable – to prevent damage from water vapor pressure a building must be able to breath and allow water vapor to pass through.
  3. UV resistant
  4. Somewhat resistant to dirt pick up.

Finish application prerequisites are:

• 1. The base coat must have cured a minimum of 24 hours or longer as required by weather conditions before the finish can be applied on the PB type system.
  2. The base coat application must be dry and hard before the finish application on PM type systems.
  3. Examine the cured base coat for any irregularities such as globs or base coat or missing base coat. Correct these irregularities before the start of the finish application.
  4. Review the environmental and application conditions.
  5. When hot and dry, work the finish on the shaded side of the building.

 

Assessing the Finish Application

In assessing the finish application, keep in mind that the material must be applied continuously for the best results. When possible, plan the day’s work to best take advantage of terminations, elevations, and aesthetic detailing. For example; work between columns, aesthetic joints, corners etc. For larger areas, sufficient manpower must be utilized to ensure an application free of cold joints and staging lines.

Direct sunlight, wind, temperature, and humidity can all have an effect on the workability and drying time of finishes.

 

Other Products and Enhancements in Finishes

Most, if not all manufacturers, offer a variety of other products that can be utilized in conjunction with finish coatings. Many make the various coatings without aggregate which can be used for recoating or detailing small color changes. Some of these paint-like coatings are enhanced with additional properties like silicone and elastomeric formulations.

A word about primers:

Some manufacturers offer, recommend, or require the addition of a base coat primer. Base coat primer is for cementitious base coats only.

The advantages of this primer are:

• 1. Protection of the cementitious base coat or substrate from water absorption.
  2. Minimize the risk of efflorescence.
  3. Provide a consistent color base for the finish product.
  4. Provide a better bond between the layers in the lamina.

Inspection consideration:

Check the specification to determine whether the system that is specified requires primers. Some systems require primers over the base coat only at the edges of the system or at sealant joints.